4107 Commits

Author SHA1 Message Date
Ojaswin Mujoo
fc7237e191 ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()
[ Upstream commit 93cdf49f6eca5e23f6546b8f28457b2e6a6961d9 ]

When the length of best extent found is less than the length of goal extent
we need to make sure that the best extent atleast covers the start of the
original request. This is done by adjusting the ac_b_ex.fe_logical (logical
start) of the extent.

While doing so, the current logic sometimes results in the best extent's
logical range overflowing the goal extent. Since this best extent is later
added to the inode preallocation list, we have a possibility of introducing
overlapping preallocations. This is discussed in detail here [1].

As per Jan's suggestion, to fix this, replace the existing logic with the
below logic for adjusting best extent as it keeps fragmentation in check
while ensuring logical range of best extent doesn't overflow out of goal
extent:

1. Check if best extent can be kept at end of goal range and still cover
   original start.
2. Else, check if best extent can be kept at start of goal range and still
   cover original start.
3. Else, keep the best extent at start of original request.

Also, add a few extra BUG_ONs that might help catch errors faster.

[1] https://lore.kernel.org/r/Y+OGkVvzPN0RMv0O@li-bb2b2a4c-3307-11b2-a85c-8fa5c3a69313.ibm.com

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/f96aca6d415b36d1f90db86c1a8cd7e2e9d7ab0e.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30 12:57:49 +01:00
Kemeng Shi
3ca3005b50 ext4: set goal start correctly in ext4_mb_normalize_request
[ Upstream commit b07ffe6927c75d99af534d685282ea188d9f71a6 ]

We need to set ac_g_ex to notify the goal start used in
ext4_mb_find_by_goal. Set ac_g_ex instead of ac_f_ex in
ext4_mb_normalize_request.
Besides we should assure goal start is in range [first_data_block,
blocks_count) as ext4_mb_initialize_context does.

[ Added a check to make sure size is less than ar->pright; otherwise
  we could end up passing an underflowed value of ar->pright - size to
  ext4_get_group_no_and_offset(), which will trigger a BUG_ON later on.
  - TYT ]

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30 12:57:49 +01:00
Theodore Ts'o
100c0ad6c0 ext4: allow ext4_get_group_info() to fail
[ Upstream commit 5354b2af34064a4579be8bc0e2f15a7b70f14b5f ]

Previously, ext4_get_group_info() would treat an invalid group number
as BUG(), since in theory it should never happen.  However, if a
malicious attaker (or fuzzer) modifies the superblock via the block
device while it is the file system is mounted, it is possible for
s_first_data_block to get set to a very large number.  In that case,
when calculating the block group of some block number (such as the
starting block of a preallocation region), could result in an
underflow and very large block group number.  Then the BUG_ON check in
ext4_get_group_info() would fire, resutling in a denial of service
attack that can be triggered by root or someone with write access to
the block device.

For a quality of implementation perspective, it's best that even if
the system administrator does something that they shouldn't, that it
will not trigger a BUG.  So instead of BUG'ing, ext4_get_group_info()
will call ext4_error and return NULL.  We also add fallback code in
all of the callers of ext4_get_group_info() that it might NULL.

Also, since ext4_get_group_info() was already borderline to be an
inline function, un-inline it.  The results in a next reduction of the
compiled text size of ext4 by roughly 2k.

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230430154311.579720-2-tytso@mit.edu
Reported-by: syzbot+e2efa3efc15a1c9e95c3@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=69b28112e098b070f639efb356393af3ffec4220
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30 12:57:47 +01:00
Kemeng Shi
371d8b8ea0 ext4: allow to find by goal if EXT4_MB_HINT_GOAL_ONLY is set
[ Upstream commit 01e4ca29451760b9ac10b4cdc231c52150842643 ]

If EXT4_MB_HINT_GOAL_ONLY is set, ext4_mb_regular_allocator will only
allocate blocks from ext4_mb_find_by_goal. Allow to find by goal in
ext4_mb_find_by_goal if EXT4_MB_HINT_GOAL_ONLY is set or allocation
with EXT4_MB_HINT_GOAL_ONLY set will always fail.

EXT4_MB_HINT_GOAL_ONLY is not used at all, so the problem is not
found for now.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-3-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 5354b2af3406 ("ext4: allow ext4_get_group_info() to fail")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30 12:57:47 +01:00
Harshad Shirwadkar
8669fff0d0 ext4: add mballoc stats proc file
[ Upstream commit a6c75eaf11032f4a3d2b3ce2265a194ac6e4a7f0 ]

Add new stats for measuring the performance of mballoc. This patch is
forked from Artem Blagodarenko's work that can be found here:

https://github.com/lustre/lustre-release/blob/master/ldiskfs/kernel_patches/patches/rhel8/ext4-simple-blockalloc.patch

This patch reorganizes the stats by cr level. This is how the output
looks like:

mballoc:
	reqs: 0
	success: 0
	groups_scanned: 0
	cr0_stats:
		hits: 0
		groups_considered: 0
		useless_loops: 0
		bad_suggestions: 0
	cr1_stats:
		hits: 0
		groups_considered: 0
		useless_loops: 0
		bad_suggestions: 0
	cr2_stats:
		hits: 0
		groups_considered: 0
		useless_loops: 0
	cr3_stats:
		hits: 0
		groups_considered: 0
		useless_loops: 0
	extents_scanned: 0
		goal_hits: 0
		2^n_hits: 0
		breaks: 0
		lost: 0
	buddies_generated: 0/40
	buddies_time_used: 0
	preallocated: 0
	discarded: 0

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Ritesh Harjani <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20210401172129.189766-4-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 5354b2af3406 ("ext4: allow ext4_get_group_info() to fail")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30 12:57:47 +01:00
Harshad Shirwadkar
9b6a0c140e ext4: drop s_mb_bal_lock and convert protected fields to atomic
[ Upstream commit 67d25186046145748d5fe4c5019d832215e01c1e ]

s_mb_buddies_generated gets used later in this patch series to
determine if the cr 0 and cr 1 optimziations should be performed or
not. Currently, s_mb_buddies_generated is protected under a
spin_lock. In the allocation path, it is better if we don't depend on
the lock and instead read the value atomically. In order to do that,
we drop s_bal_lock altogether and we convert the only two protected
fields by it s_mb_buddies_generated and s_mb_generation_time to atomic
type.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Ritesh Harjani <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20210401172129.189766-2-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 5354b2af3406 ("ext4: allow ext4_get_group_info() to fail")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30 12:57:47 +01:00
Chunguang Xu
0983142c5f ext4: remove redundant mb_regenerate_buddy()
[ Upstream commit 6bd97bf273bdb4944904e57480f6545bca48ad77 ]

After this patch (163a203), if an abnormal bitmap is detected, we
will mark the group as corrupt, and we will not use this group in
the future. Therefore, it should be meaningless to regenerate the
buddy bitmap of this group, It might be better to delete it.

Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/1604764698-4269-2-git-send-email-brookxu@tencent.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 5354b2af3406 ("ext4: allow ext4_get_group_info() to fail")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30 12:57:47 +01:00
Jan Kara
d48b7eea94 ext4: fix lockdep warning when enabling MMP
[ Upstream commit 949f95ff39bf188e594e7ecd8e29b82eb108f5bf ]

When we enable MMP in ext4_multi_mount_protect() during mount or
remount, we end up calling sb_start_write() from write_mmp_block(). This
triggers lockdep warning because freeze protection ranks above s_umount
semaphore we are holding during mount / remount. The problem is harmless
because we are guaranteed the filesystem is not frozen during mount /
remount but still let's fix the warning by not grabbing freeze
protection from ext4_multi_mount_protect().

Cc: stable@kernel.org
Reported-by: syzbot+6b7df7d5506b32467149@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=ab7e5b6f400b7778d46f01841422e5718fb81843
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230411121019.21940-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30 12:57:47 +01:00
Theodore Ts'o
5c87115520 ext4: don't clear SB_RDONLY when remounting r/w until quota is re-enabled
[ Upstream commit a44be64bbecb15a452496f60db6eacfee2b59c79 ]

When a file system currently mounted read/only is remounted
read/write, if we clear the SB_RDONLY flag too early, before the quota
is initialized, and there is another process/thread constantly
attempting to create a directory, it's possible to trigger the

	WARN_ON_ONCE(dquot_initialize_needed(inode));

in ext4_xattr_block_set(), with the following stack trace:

   WARNING: CPU: 0 PID: 5338 at fs/ext4/xattr.c:2141 ext4_xattr_block_set+0x2ef2/0x3680
   RIP: 0010:ext4_xattr_block_set+0x2ef2/0x3680 fs/ext4/xattr.c:2141
   Call Trace:
    ext4_xattr_set_handle+0xcd4/0x15c0 fs/ext4/xattr.c:2458
    ext4_initxattrs+0xa3/0x110 fs/ext4/xattr_security.c:44
    security_inode_init_security+0x2df/0x3f0 security/security.c:1147
    __ext4_new_inode+0x347e/0x43d0 fs/ext4/ialloc.c:1324
    ext4_mkdir+0x425/0xce0 fs/ext4/namei.c:2992
    vfs_mkdir+0x29d/0x450 fs/namei.c:4038
    do_mkdirat+0x264/0x520 fs/namei.c:4061
    __do_sys_mkdirat fs/namei.c:4076 [inline]
    __se_sys_mkdirat fs/namei.c:4074 [inline]
    __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4074

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230506142419.984260-1-tytso@mit.edu
Reported-by: syzbot+6385d7d3065524c5ca6d@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=6513f6cb5cd6b5fc9f37e3bb70d273b94be9c34c
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30 12:57:47 +01:00
Theodore Ts'o
8284c7592d ext4: reflect error codes from ext4_multi_mount_protect() to its callers
[ Upstream commit 3b50d5018ed06a647bb26c44bb5ae74e59c903c7 ]

This will allow more fine-grained errno codes to be returned by the
mount system call.

Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: a44be64bbecb ("ext4: don't clear SB_RDONLY when remounting r/w until quota is re-enabled")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30 12:57:47 +01:00
Austin Kim
efd18a91c9 ext4: remove an unused variable warning with CONFIG_QUOTA=n
[ Upstream commit 3bbef91bdd2180c67407285ba160b023eb4d5306 ]

The 'enable_quota' variable is only used in an CONFIG_QUOTA.
With CONFIG_QUOTA=n, compiler causes a harmless warning:

fs/ext4/super.c: In function ‘ext4_remount’:
fs/ext4/super.c:5840:6: warning: variable ‘enable_quota’ set but not used
  [-Wunused-but-set-variable]
  int enable_quota = 0;
              ^~~~~

Move 'enable_quota' into the same #ifdef CONFIG_QUOTA block
to remove an unused variable warning.

Signed-off-by: Austin Kim <austindh.kim@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210824034929.GA13415@raspberrypi
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: a44be64bbecb ("ext4: don't clear SB_RDONLY when remounting r/w until quota is re-enabled")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30 12:57:47 +01:00
Theodore Ts'o
1a8822343e ext4: fix invalid free tracking in ext4_xattr_move_to_block()
commit b87c7cdf2bed4928b899e1ce91ef0d147017ba45 upstream.

In ext4_xattr_move_to_block(), the value of the extended attribute
which we need to move to an external block may be allocated by
kvmalloc() if the value is stored in an external inode.  So at the end
of the function the code tried to check if this was the case by
testing entry->e_value_inum.

However, at this point, the pointer to the xattr entry is no longer
valid, because it was removed from the original location where it had
been stored.  So we could end up calling kvfree() on a pointer which
was not allocated by kvmalloc(); or we could also potentially leak
memory by not freeing the buffer when it should be freed.  Fix this by
storing whether it should be freed in a separate variable.

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230430160426.581366-1-tytso@mit.edu
Link: https://syzkaller.appspot.com/bug?id=5c2aee8256e30b55ccf57312c16d88417adbd5e1
Link: https://syzkaller.appspot.com/bug?id=41a6b5d4917c0412eb3b3c3c604965bed7d7420b
Reported-by: syzbot+64b645917ce07d89bde5@syzkaller.appspotmail.com
Reported-by: syzbot+0d042627c4f2ad332195@syzkaller.appspotmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17 11:48:18 +02:00
Theodore Ts'o
b0fc279de4 ext4: remove a BUG_ON in ext4_mb_release_group_pa()
commit 463808f237cf73e98a1a45ff7460c2406a150a0b upstream.

If a malicious fuzzer overwrites the ext4 superblock while it is
mounted such that the s_first_data_block is set to a very large
number, the calculation of the block group can underflow, and trigger
a BUG_ON check.  Change this to be an ext4_warning so that we don't
crash the kernel.

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230430154311.579720-3-tytso@mit.edu
Reported-by: syzbot+e2efa3efc15a1c9e95c3@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=69b28112e098b070f639efb356393af3ffec4220
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17 11:48:17 +02:00
Theodore Ts'o
d88fe8e611 ext4: bail out of ext4_xattr_ibody_get() fails for any reason
commit 2a534e1d0d1591e951f9ece2fb460b2ff92edabd upstream.

In ext4_update_inline_data(), if ext4_xattr_ibody_get() fails for any
reason, it's best if we just fail as opposed to stumbling on,
especially if the failure is EFSCORRUPTED.

Cc: stable@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17 11:48:17 +02:00
Theodore Ts'o
4597554b4f ext4: add bounds checking in get_max_inline_xattr_value_size()
commit 2220eaf90992c11d888fe771055d4de330385f01 upstream.

Normally the extended attributes in the inode body would have been
checked when the inode is first opened, but if someone is writing to
the block device while the file system is mounted, it's possible for
the inode table to get corrupted.  Add bounds checking to avoid
reading beyond the end of allocated memory if this happens.

Reported-by: syzbot+1966db24521e5f6e23f7@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=1966db24521e5f6e23f7
Cc: stable@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17 11:48:17 +02:00
Theodore Ts'o
5f8b55136a ext4: fix deadlock when converting an inline directory in nojournal mode
commit f4ce24f54d9cca4f09a395f3eecce20d6bec4663 upstream.

In no journal mode, ext4_finish_convert_inline_dir() can self-deadlock
by calling ext4_handle_dirty_dirblock() when it already has taken the
directory lock.  There is a similar self-deadlock in
ext4_incvert_inline_data_nolock() for data files which we'll fix at
the same time.

A simple reproducer demonstrating the problem:

    mke2fs -Fq -t ext2 -O inline_data -b 4k /dev/vdc 64
    mount -t ext4 -o dirsync /dev/vdc /vdc
    cd /vdc
    mkdir file0
    cd file0
    touch file0
    touch file1
    attr -s BurnSpaceInEA -V abcde .
    touch supercalifragilisticexpialidocious

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230507021608.1290720-1-tytso@mit.edu
Reported-by: syzbot+91dccab7c64e2850a4e5@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=ba84cc80a9491d65416bc7877e1650c87530fe8a
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17 11:48:17 +02:00
Theodore Ts'o
37c69da3ad ext4: improve error recovery code paths in __ext4_remount()
commit 4c0b4818b1f636bc96359f7817a2d8bab6370162 upstream.

If there are failures while changing the mount options in
__ext4_remount(), we need to restore the old mount options.

This commit fixes two problem.  The first is there is a chance that we
will free the old quota file names before a potential failure leading
to a use-after-free.  The second problem addressed in this commit is
if there is a failed read/write to read-only transition, if the quota
has already been suspended, we need to renable quota handling.

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230506142419.984260-2-tytso@mit.edu
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17 11:48:17 +02:00
Baokun Li
08838aeefa ext4: check iomap type only if ext4_iomap_begin() does not fail
commit fa83c34e3e56b3c672af38059e066242655271b1 upstream.

When ext4_iomap_overwrite_begin() calls ext4_iomap_begin() map blocks may
fail for some reason (e.g. memory allocation failure, bare disk write), and
later because "iomap->type ! = IOMAP_MAPPED" triggers WARN_ON(). When ext4
iomap_begin() returns an error, it is normal that the type of iomap->type
may not match the expectation. Therefore, we only determine if iomap->type
is as expected when ext4_iomap_begin() is executed successfully.

Cc: stable@kernel.org
Reported-by: syzbot+08106c4b7d60702dbc14@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/00000000000015760b05f9b4eee9@google.com
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230505132429.714648-1-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17 11:48:17 +02:00
Jan Kara
4aa7f744fa ext4: fix data races when using cached status extents
commit 492888df0c7b42fc0843631168b0021bc4caee84 upstream.

When using cached extent stored in extent status tree in tree->cache_es
another process holding ei->i_es_lock for reading can be racing with us
setting new value of tree->cache_es. If the compiler would decide to
refetch tree->cache_es at an unfortunate moment, it could result in a
bogus in_range() check. Fix the possible race by using READ_ONCE() when
using tree->cache_es only under ei->i_es_lock for reading.

Cc: stable@kernel.org
Reported-by: syzbot+4a03518df1e31b537066@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/000000000000d3b33905fa0fd4a6@google.com
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230504125524.10802-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17 11:48:17 +02:00
Tudor Ambarus
0dde3141c5 ext4: avoid a potential slab-out-of-bounds in ext4_group_desc_csum
commit 4f04351888a83e595571de672e0a4a8b74f4fb31 upstream.

When modifying the block device while it is mounted by the filesystem,
syzbot reported the following:

BUG: KASAN: slab-out-of-bounds in crc16+0x206/0x280 lib/crc16.c:58
Read of size 1 at addr ffff888075f5c0a8 by task syz-executor.2/15586

CPU: 1 PID: 15586 Comm: syz-executor.2 Not tainted 6.2.0-rc5-syzkaller-00205-gc96618275234 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
 print_address_description+0x74/0x340 mm/kasan/report.c:306
 print_report+0x107/0x1f0 mm/kasan/report.c:417
 kasan_report+0xcd/0x100 mm/kasan/report.c:517
 crc16+0x206/0x280 lib/crc16.c:58
 ext4_group_desc_csum+0x81b/0xb20 fs/ext4/super.c:3187
 ext4_group_desc_csum_set+0x195/0x230 fs/ext4/super.c:3210
 ext4_mb_clear_bb fs/ext4/mballoc.c:6027 [inline]
 ext4_free_blocks+0x191a/0x2810 fs/ext4/mballoc.c:6173
 ext4_remove_blocks fs/ext4/extents.c:2527 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2710 [inline]
 ext4_ext_remove_space+0x24ef/0x46a0 fs/ext4/extents.c:2958
 ext4_ext_truncate+0x177/0x220 fs/ext4/extents.c:4416
 ext4_truncate+0xa6a/0xea0 fs/ext4/inode.c:4342
 ext4_setattr+0x10c8/0x1930 fs/ext4/inode.c:5622
 notify_change+0xe50/0x1100 fs/attr.c:482
 do_truncate+0x200/0x2f0 fs/open.c:65
 handle_truncate fs/namei.c:3216 [inline]
 do_open fs/namei.c:3561 [inline]
 path_openat+0x272b/0x2dd0 fs/namei.c:3714
 do_filp_open+0x264/0x4f0 fs/namei.c:3741
 do_sys_openat2+0x124/0x4e0 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_creat fs/open.c:1402 [inline]
 __se_sys_creat fs/open.c:1396 [inline]
 __x64_sys_creat+0x11f/0x160 fs/open.c:1396
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f72f8a8c0c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f72f97e3168 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f72f8bac050 RCX: 00007f72f8a8c0c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000280
RBP: 00007f72f8ae7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd165348bf R14: 00007f72f97e3300 R15: 0000000000022000

Replace
	le16_to_cpu(sbi->s_es->s_desc_size)
with
	sbi->s_desc_size

It reduces ext4's compiled text size, and makes the code more efficient
(we remove an extra indirect reference and a potential byte
swap on big endian systems), and there is no downside. It also avoids the
potential KASAN / syzkaller failure, as a bonus.

Reported-by: syzbot+fc51227e7100c9294894@syzkaller.appspotmail.com
Reported-by: syzbot+8785e41224a3afd04321@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=70d28d11ab14bd7938f3e088365252aa923cff42
Link: https://syzkaller.appspot.com/bug?id=b85721b38583ecc6b5e72ff524c67302abbc30f3
Link: https://lore.kernel.org/all/000000000000ece18705f3b20934@google.com/
Fixes: 717d50e4971b ("Ext4: Uninitialized Block Groups")
Cc: stable@vger.kernel.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20230504121525.3275886-1-tudor.ambarus@linaro.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17 11:48:17 +02:00
Ye Bin
5d356d902e ext4: fix WARNING in mb_find_extent
commit fa08a7b61dff8a4df11ff1e84abfc214b487caf7 upstream.

Syzbot found the following issue:

EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!
EXT4-fs (loop0): orphan cleanup on readonly fs
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5067 at fs/ext4/mballoc.c:1869 mb_find_extent+0x8a1/0xe30
Modules linked in:
CPU: 1 PID: 5067 Comm: syz-executor307 Not tainted 6.2.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:mb_find_extent+0x8a1/0xe30 fs/ext4/mballoc.c:1869
RSP: 0018:ffffc90003c9e098 EFLAGS: 00010293
RAX: ffffffff82405731 RBX: 0000000000000041 RCX: ffff8880783457c0
RDX: 0000000000000000 RSI: 0000000000000041 RDI: 0000000000000040
RBP: 0000000000000040 R08: ffffffff82405723 R09: ffffed10053c9402
R10: ffffed10053c9402 R11: 1ffff110053c9401 R12: 0000000000000000
R13: ffffc90003c9e538 R14: dffffc0000000000 R15: ffffc90003c9e2cc
FS:  0000555556665300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056312f6796f8 CR3: 0000000022437000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_mb_complex_scan_group+0x353/0x1100 fs/ext4/mballoc.c:2307
 ext4_mb_regular_allocator+0x1533/0x3860 fs/ext4/mballoc.c:2735
 ext4_mb_new_blocks+0xddf/0x3db0 fs/ext4/mballoc.c:5605
 ext4_ext_map_blocks+0x1868/0x6880 fs/ext4/extents.c:4286
 ext4_map_blocks+0xa49/0x1cc0 fs/ext4/inode.c:651
 ext4_getblk+0x1b9/0x770 fs/ext4/inode.c:864
 ext4_bread+0x2a/0x170 fs/ext4/inode.c:920
 ext4_quota_write+0x225/0x570 fs/ext4/super.c:7105
 write_blk fs/quota/quota_tree.c:64 [inline]
 get_free_dqblk+0x34a/0x6d0 fs/quota/quota_tree.c:130
 do_insert_tree+0x26b/0x1aa0 fs/quota/quota_tree.c:340
 do_insert_tree+0x722/0x1aa0 fs/quota/quota_tree.c:375
 do_insert_tree+0x722/0x1aa0 fs/quota/quota_tree.c:375
 do_insert_tree+0x722/0x1aa0 fs/quota/quota_tree.c:375
 dq_insert_tree fs/quota/quota_tree.c:401 [inline]
 qtree_write_dquot+0x3b6/0x530 fs/quota/quota_tree.c:420
 v2_write_dquot+0x11b/0x190 fs/quota/quota_v2.c:358
 dquot_acquire+0x348/0x670 fs/quota/dquot.c:444
 ext4_acquire_dquot+0x2dc/0x400 fs/ext4/super.c:6740
 dqget+0x999/0xdc0 fs/quota/dquot.c:914
 __dquot_initialize+0x3d0/0xcf0 fs/quota/dquot.c:1492
 ext4_process_orphan+0x57/0x2d0 fs/ext4/orphan.c:329
 ext4_orphan_cleanup+0xb60/0x1340 fs/ext4/orphan.c:474
 __ext4_fill_super fs/ext4/super.c:5516 [inline]
 ext4_fill_super+0x81cd/0x8700 fs/ext4/super.c:5644
 get_tree_bdev+0x400/0x620 fs/super.c:1282
 vfs_get_tree+0x88/0x270 fs/super.c:1489
 do_new_mount+0x289/0xad0 fs/namespace.c:3145
 do_mount fs/namespace.c:3488 [inline]
 __do_sys_mount fs/namespace.c:3697 [inline]
 __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3674
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Add some debug information:
mb_find_extent: mb_find_extent block=41, order=0 needed=64 next=0 ex=0/41/1@3735929054 64 64 7
block_bitmap: ff 3f 0c 00 fc 01 00 00 d2 3d 00 00 00 00 00 00 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

Acctually, blocks per group is 64, but block bitmap indicate at least has
128 blocks. Now, ext4_validate_block_bitmap() didn't check invalid block's
bitmap if set.
To resolve above issue, add check like fsck "Padding at end of block bitmap is
not set".

Cc: stable@kernel.org
Reported-by: syzbot+68223fe9f6c95ad43bed@syzkaller.appspotmail.com
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230116020015.1506120-1-yebin@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17 11:48:16 +02:00
Ye Bin
770b061363 ext4: fix use-after-free read in ext4_find_extent for bigalloc + inline
[ Upstream commit 835659598c67907b98cd2aa57bb951dfaf675c69 ]

Syzbot found the following issue:
loop0: detected capacity change from 0 to 2048
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: none.
==================================================================
BUG: KASAN: use-after-free in ext4_ext_binsearch_idx fs/ext4/extents.c:768 [inline]
BUG: KASAN: use-after-free in ext4_find_extent+0x76e/0xd90 fs/ext4/extents.c:931
Read of size 4 at addr ffff888073644750 by task syz-executor420/5067

CPU: 0 PID: 5067 Comm: syz-executor420 Not tainted 6.2.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
 print_address_description+0x74/0x340 mm/kasan/report.c:306
 print_report+0x107/0x1f0 mm/kasan/report.c:417
 kasan_report+0xcd/0x100 mm/kasan/report.c:517
 ext4_ext_binsearch_idx fs/ext4/extents.c:768 [inline]
 ext4_find_extent+0x76e/0xd90 fs/ext4/extents.c:931
 ext4_clu_mapped+0x117/0x970 fs/ext4/extents.c:5809
 ext4_insert_delayed_block fs/ext4/inode.c:1696 [inline]
 ext4_da_map_blocks fs/ext4/inode.c:1806 [inline]
 ext4_da_get_block_prep+0x9e8/0x13c0 fs/ext4/inode.c:1870
 ext4_block_write_begin+0x6a8/0x2290 fs/ext4/inode.c:1098
 ext4_da_write_begin+0x539/0x760 fs/ext4/inode.c:3082
 generic_perform_write+0x2e4/0x5e0 mm/filemap.c:3772
 ext4_buffered_write_iter+0x122/0x3a0 fs/ext4/file.c:285
 ext4_file_write_iter+0x1d0/0x18f0
 call_write_iter include/linux/fs.h:2186 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x7dc/0xc50 fs/read_write.c:584
 ksys_write+0x177/0x2a0 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f4b7a9737b9
RSP: 002b:00007ffc5cac3668 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4b7a9737b9
RDX: 00000000175d9003 RSI: 0000000020000200 RDI: 0000000000000004
RBP: 00007f4b7a933050 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000079f R11: 0000000000000246 R12: 00007f4b7a9330e0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Above issue is happens when enable bigalloc and inline data feature. As
commit 131294c35ed6 fixed delayed allocation bug in ext4_clu_mapped for
bigalloc + inline. But it only resolved issue when has inline data, if
inline data has been converted to extent(ext4_da_convert_inline_data_to_extent)
before writepages, there is no EXT4_STATE_MAY_INLINE_DATA flag. However
i_data is still store inline data in this scene. Then will trigger UAF
when find extent.
To resolve above issue, there is need to add judge "ext4_has_inline_data(inode)"
in ext4_clu_mapped().

Fixes: 131294c35ed6 ("ext4: fix delayed allocation bug in ext4_clu_mapped for bigalloc + inline")
Reported-by: syzbot+bf4bb7731ef73b83a3b4@syzkaller.appspotmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Tested-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20230406111627.1916759-1-tudor.ambarus@linaro.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-17 11:48:03 +02:00
Harshad Shirwadkar
c8714ddf3c ext4: use ext4_journal_start/stop for fast commit transactions
commit 2729cfdcfa1cc49bef5a90d046fa4a187fdfcc69 upstream.

This patch drops all calls to ext4_fc_start_update() and
ext4_fc_stop_update(). To ensure that there are no ongoing journal
updates during fast commit, we also make jbd2_fc_begin_commit() lock
journal for updates. This way we don't have to maintain two different
transaction start stop APIs for fast commit and full commit. This
patch doesn't remove the functions altogether since in future we want
to have inode level locking for fast commits.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20211223202140.2061101-2-harshads@google.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17 11:47:32 +02:00
Baokun Li
05cf34a2b6 ext4: fix use-after-free in ext4_xattr_set_entry
[ Upstream commit 67d7d8ad99beccd9fe92d585b87f1760dc9018e3 ]

Hulk Robot reported a issue:
==================================================================
BUG: KASAN: use-after-free in ext4_xattr_set_entry+0x18ab/0x3500
Write of size 4105 at addr ffff8881675ef5f4 by task syz-executor.0/7092

CPU: 1 PID: 7092 Comm: syz-executor.0 Not tainted 4.19.90-dirty #17
Call Trace:
[...]
 memcpy+0x34/0x50 mm/kasan/kasan.c:303
 ext4_xattr_set_entry+0x18ab/0x3500 fs/ext4/xattr.c:1747
 ext4_xattr_ibody_inline_set+0x86/0x2a0 fs/ext4/xattr.c:2205
 ext4_xattr_set_handle+0x940/0x1300 fs/ext4/xattr.c:2386
 ext4_xattr_set+0x1da/0x300 fs/ext4/xattr.c:2498
 __vfs_setxattr+0x112/0x170 fs/xattr.c:149
 __vfs_setxattr_noperm+0x11b/0x2a0 fs/xattr.c:180
 __vfs_setxattr_locked+0x17b/0x250 fs/xattr.c:238
 vfs_setxattr+0xed/0x270 fs/xattr.c:255
 setxattr+0x235/0x330 fs/xattr.c:520
 path_setxattr+0x176/0x190 fs/xattr.c:539
 __do_sys_lsetxattr fs/xattr.c:561 [inline]
 __se_sys_lsetxattr fs/xattr.c:557 [inline]
 __x64_sys_lsetxattr+0xc2/0x160 fs/xattr.c:557
 do_syscall_64+0xdf/0x530 arch/x86/entry/common.c:298
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x459fe9
RSP: 002b:00007fa5e54b4c08 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 000000000051bf60 RCX: 0000000000459fe9
RDX: 00000000200003c0 RSI: 0000000020000180 RDI: 0000000020000140
RBP: 000000000051bf60 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000001009 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc73c93fc0 R14: 000000000051bf60 R15: 00007fa5e54b4d80
[...]
==================================================================

Above issue may happen as follows:
-------------------------------------
ext4_xattr_set
  ext4_xattr_set_handle
    ext4_xattr_ibody_find
      >> s->end < s->base
      >> no EXT4_STATE_XATTR
      >> xattr_check_inode is not executed
    ext4_xattr_ibody_set
      ext4_xattr_set_entry
       >> size_t min_offs = s->end - s->base
       >> UAF in memcpy

we can easily reproduce this problem with the following commands:
    mkfs.ext4 -F /dev/sda
    mount -o debug_want_extra_isize=128 /dev/sda /mnt
    touch /mnt/file
    setfattr -n user.cat -v `seq -s z 4096|tr -d '[:digit:]'` /mnt/file

In ext4_xattr_ibody_find, we have the following assignment logic:
  header = IHDR(inode, raw_inode)
         = raw_inode + EXT4_GOOD_OLD_INODE_SIZE + i_extra_isize
  is->s.base = IFIRST(header)
             = header + sizeof(struct ext4_xattr_ibody_header)
  is->s.end = raw_inode + s_inode_size

In ext4_xattr_set_entry
  min_offs = s->end - s->base
           = s_inode_size - EXT4_GOOD_OLD_INODE_SIZE - i_extra_isize -
	     sizeof(struct ext4_xattr_ibody_header)
  last = s->first
  free = min_offs - ((void *)last - s->base) - sizeof(__u32)
       = s_inode_size - EXT4_GOOD_OLD_INODE_SIZE - i_extra_isize -
         sizeof(struct ext4_xattr_ibody_header) - sizeof(__u32)

In the calculation formula, all values except s_inode_size and
i_extra_size are fixed values. When i_extra_size is the maximum value
s_inode_size - EXT4_GOOD_OLD_INODE_SIZE, min_offs is -4 and free is -8.
The value overflows. As a result, the preceding issue is triggered when
memcpy is executed.

Therefore, when finding xattr or setting xattr, check whether
there is space for storing xattr in the inode to resolve this issue.

Cc: stable@kernel.org
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220616021358.2504451-3-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-26 11:27:41 +02:00
Ritesh Harjani
c75711396c ext4: remove duplicate definition of ext4_xattr_ibody_inline_set()
[ Upstream commit 310c097c2bdbea253d6ee4e064f3e65580ef93ac ]

ext4_xattr_ibody_inline_set() & ext4_xattr_ibody_set() have the exact
same definition.  Hence remove ext4_xattr_ibody_inline_set() and all
its call references. Convert the callers of it to call
ext4_xattr_ibody_set() instead.

[ Modified to preserve ext4_xattr_ibody_set() and remove
  ext4_xattr_ibody_inline_set() instead. -- TYT ]

Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/fd566b799bbbbe9b668eb5eecde5b5e319e3694f.1622685482.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-26 11:27:41 +02:00
Tudor Ambarus
9400206d9d Revert "ext4: fix use-after-free in ext4_xattr_set_entry"
This reverts commit bb8592efcf8ef2f62947745d3182ea05b5256a15 which is
commit 67d7d8ad99beccd9fe92d585b87f1760dc9018e3 upstream.

The order in which patches are queued to stable matters. This patch
has a logical dependency on commit 310c097c2bdbea253d6ee4e064f3e65580ef93ac
upstream, and failing to queue the latter results in a null-ptr-deref
reported at the Link below.

In order to avoid conflicts on stable, revert the commit just so that we
can queue its prerequisite patch first and then queue the same after.

Link: https://syzkaller.appspot.com/bug?extid=d5ebf56f3b1268136afd
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-26 11:27:41 +02:00
Ye Bin
3392d67af0 ext4: fix kernel BUG in 'ext4_write_inline_data_end()'
commit 5c099c4fdc438014d5893629e70a8ba934433ee8 upstream.

Syzbot report follow issue:
------------[ cut here ]------------
kernel BUG at fs/ext4/inline.c:227!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 3629 Comm: syz-executor212 Not tainted 6.1.0-rc5-syzkaller-00018-g59d0d52c30d4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:ext4_write_inline_data+0x344/0x3e0 fs/ext4/inline.c:227
RSP: 0018:ffffc90003b3f368 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff8880704e16c0 RCX: 0000000000000000
RDX: ffff888021763a80 RSI: ffffffff821e31a4 RDI: 0000000000000006
RBP: 000000000006818e R08: 0000000000000006 R09: 0000000000068199
R10: 0000000000000079 R11: 0000000000000000 R12: 000000000000000b
R13: 0000000000068199 R14: ffffc90003b3f408 R15: ffff8880704e1c82
FS:  000055555723e3c0(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffe8ac9080 CR3: 0000000079f81000 CR4: 0000000000350ee0
Call Trace:
 <TASK>
 ext4_write_inline_data_end+0x2a3/0x12f0 fs/ext4/inline.c:768
 ext4_write_end+0x242/0xdd0 fs/ext4/inode.c:1313
 ext4_da_write_end+0x3ed/0xa30 fs/ext4/inode.c:3063
 generic_perform_write+0x316/0x570 mm/filemap.c:3764
 ext4_buffered_write_iter+0x15b/0x460 fs/ext4/file.c:285
 ext4_file_write_iter+0x8bc/0x16e0 fs/ext4/file.c:700
 call_write_iter include/linux/fs.h:2191 [inline]
 do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735
 do_iter_write+0x182/0x700 fs/read_write.c:861
 vfs_iter_write+0x74/0xa0 fs/read_write.c:902
 iter_file_splice_write+0x745/0xc90 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x114/0x180 fs/splice.c:931
 splice_direct_to_actor+0x335/0x8a0 fs/splice.c:886
 do_splice_direct+0x1ab/0x280 fs/splice.c:974
 do_sendfile+0xb19/0x1270 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x1d0/0x210 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
---[ end trace 0000000000000000 ]---

Above issue may happens as follows:
ext4_da_write_begin
  ext4_da_write_inline_data_begin
    ext4_da_convert_inline_data_to_extent
      ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
ext4_da_write_end

ext4_run_li_request
  ext4_mb_prefetch
    ext4_read_block_bitmap_nowait
      ext4_validate_block_bitmap
        ext4_mark_group_bitmap_corrupted(sb, block_group, EXT4_GROUP_INFO_BBITMAP_CORRUPT)
	 percpu_counter_sub(&sbi->s_freeclusters_counter,grp->bb_free);
	  -> sbi->s_freeclusters_counter become zero
ext4_da_write_begin
  if (ext4_nonda_switch(inode->i_sb)) -> As freeclusters_counter is zero will return true
    *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
    ext4_write_begin
ext4_da_write_end
  if (write_mode == FALL_BACK_TO_NONDELALLOC)
    ext4_write_end
      if (inline_data)
        ext4_write_inline_data_end
	  ext4_write_inline_data
	    BUG_ON(pos + len > EXT4_I(inode)->i_inline_size);
           -> As inode is already convert to extent, so 'pos + len' > inline_size
	   -> then trigger BUG.

To solve this issue, instead of checking ext4_has_inline_data() which
is only cleared after data has been written back, check the
EXT4_STATE_MAY_INLINE_DATA flag in ext4_write_end().

Fixes: f19d5870cbf7 ("ext4: add normal write support for inline data")
Reported-by: syzbot+4faa160fa96bfba639f8@syzkaller.appspotmail.com
Reported-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Link: https://lore.kernel.org/r/20221206144134.1919987-1-yebin@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
[ta: Fix conflict in if expression and use the local variable inline_data
as it is initialized with ext4_has_inline_data(inode) anyway.]
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 11:23:52 +02:00
Theodore Ts'o
020166bc66 ext4: fix possible double unlock when moving a directory
commit 70e42feab2e20618ddd0cbfc4ab4b08628236ecd upstream.

Fixes: 0813299c586b ("ext4: Fix possible corruption when moving a directory")
Link: https://lore.kernel.org/r/5efbe1b9-ad8b-4a4f-b422-24824d2b775c@kili.mountain
Reported-by: Dan Carpenter <error27@gmail.com>
Reported-by: syzbot+0c73d1d8b952c5f3d714@syzkaller.appspotmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-22 13:30:02 +01:00
Baokun Li
a98160d8f3 ext4: fix task hung in ext4_xattr_delete_inode
[ Upstream commit 0f7bfd6f8164be32dbbdf36aa1e5d00485c53cd7 ]

Syzbot reported a hung task problem:
==================================================================
INFO: task syz-executor232:5073 blocked for more than 143 seconds.
      Not tainted 6.2.0-rc2-syzkaller-00024-g512dee0c00ad #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-exec232 state:D stack:21024 pid:5073 ppid:5072 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x995/0xe20 kernel/sched/core.c:6555
 schedule+0xcb/0x190 kernel/sched/core.c:6631
 __wait_on_freeing_inode fs/inode.c:2196 [inline]
 find_inode_fast+0x35a/0x4c0 fs/inode.c:950
 iget_locked+0xb1/0x830 fs/inode.c:1273
 __ext4_iget+0x22e/0x3ed0 fs/ext4/inode.c:4861
 ext4_xattr_inode_iget+0x68/0x4e0 fs/ext4/xattr.c:389
 ext4_xattr_inode_dec_ref_all+0x1a7/0xe50 fs/ext4/xattr.c:1148
 ext4_xattr_delete_inode+0xb04/0xcd0 fs/ext4/xattr.c:2880
 ext4_evict_inode+0xd7c/0x10b0 fs/ext4/inode.c:296
 evict+0x2a4/0x620 fs/inode.c:664
 ext4_orphan_cleanup+0xb60/0x1340 fs/ext4/orphan.c:474
 __ext4_fill_super fs/ext4/super.c:5516 [inline]
 ext4_fill_super+0x81cd/0x8700 fs/ext4/super.c:5644
 get_tree_bdev+0x400/0x620 fs/super.c:1282
 vfs_get_tree+0x88/0x270 fs/super.c:1489
 do_new_mount+0x289/0xad0 fs/namespace.c:3145
 do_mount fs/namespace.c:3488 [inline]
 __do_sys_mount fs/namespace.c:3697 [inline]
 __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3674
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fa5406fd5ea
RSP: 002b:00007ffc7232f968 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fa5406fd5ea
RDX: 0000000020000440 RSI: 0000000020000000 RDI: 00007ffc7232f970
RBP: 00007ffc7232f970 R08: 00007ffc7232f9b0 R09: 0000000000000432
R10: 0000000000804a03 R11: 0000000000000202 R12: 0000000000000004
R13: 0000555556a7a2c0 R14: 00007ffc7232f9b0 R15: 0000000000000000
 </TASK>
==================================================================

The problem is that the inode contains an xattr entry with ea_inum of 15
when cleaning up an orphan inode <15>. When evict inode <15>, the reference
counting of the corresponding EA inode is decreased. When EA inode <15> is
found by find_inode_fast() in __ext4_iget(), it is found that the EA inode
holds the I_FREEING flag and waits for the EA inode to complete deletion.
As a result, when inode <15> is being deleted, we wait for inode <15> to
complete the deletion, resulting in an infinite loop and triggering Hung
Task. To solve this problem, we only need to check whether the ino of EA
inode and parent is the same before getting EA inode.

Link: https://syzkaller.appspot.com/bug?extid=77d6fcc37bbb92f26048
Reported-by: syzbot+77d6fcc37bbb92f26048@syzkaller.appspotmail.com
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230110133436.996350-1-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-22 13:30:02 +01:00
Baokun Li
0bf15bc393 ext4: fail ext4_iget if special inode unallocated
[ Upstream commit 5cd740287ae5e3f9d1c46f5bfe8778972fd6d3fe ]

In ext4_fill_super(), EXT4_ORPHAN_FS flag is cleared after
ext4_orphan_cleanup() is executed. Therefore, when __ext4_iget() is
called to get an inode whose i_nlink is 0 when the flag exists, no error
is returned. If the inode is a special inode, a null pointer dereference
may occur. If the value of i_nlink is 0 for any inodes (except boot loader
inodes) got by using the EXT4_IGET_SPECIAL flag, the current file system
is corrupted. Therefore, make the ext4_iget() function return an error if
it gets such an abnormal special inode.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=199179
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216541
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216539
Reported-by: Luís Henriques <lhenriques@suse.de>
Suggested-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230107032126.4165860-2-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-22 13:30:02 +01:00
Lukas Czerner
7550aade97 ext4: block range must be validated before use in ext4_mb_clear_bb()
commit 1e1c2b86ef86a8477fd9b9a4f48a6bfe235606f6 upstream.

Block range to free is validated in ext4_free_blocks() using
ext4_inode_block_valid() and then it's passed to ext4_mb_clear_bb().
However in some situations on bigalloc file system the range might be
adjusted after the validation in ext4_free_blocks() which can lead to
troubles on corrupted file systems such as one found by syzkaller that
resulted in the following BUG

kernel BUG at fs/ext4/ext4.h:3319!
PREEMPT SMP NOPTI
CPU: 28 PID: 4243 Comm: repro Kdump: loaded Not tainted 5.19.0-rc6+ #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014
RIP: 0010:ext4_free_blocks+0x95e/0xa90
Call Trace:
 <TASK>
 ? lock_timer_base+0x61/0x80
 ? __es_remove_extent+0x5a/0x760
 ? __mod_timer+0x256/0x380
 ? ext4_ind_truncate_ensure_credits+0x90/0x220
 ext4_clear_blocks+0x107/0x1b0
 ext4_free_data+0x15b/0x170
 ext4_ind_truncate+0x214/0x2c0
 ? _raw_spin_unlock+0x15/0x30
 ? ext4_discard_preallocations+0x15a/0x410
 ? ext4_journal_check_start+0xe/0x90
 ? __ext4_journal_start_sb+0x2f/0x110
 ext4_truncate+0x1b5/0x460
 ? __ext4_journal_start_sb+0x2f/0x110
 ext4_evict_inode+0x2b4/0x6f0
 evict+0xd0/0x1d0
 ext4_enable_quotas+0x11f/0x1f0
 ext4_orphan_cleanup+0x3de/0x430
 ? proc_create_seq_private+0x43/0x50
 ext4_fill_super+0x295f/0x3ae0
 ? snprintf+0x39/0x40
 ? sget_fc+0x19c/0x330
 ? ext4_reconfigure+0x850/0x850
 get_tree_bdev+0x16d/0x260
 vfs_get_tree+0x25/0xb0
 path_mount+0x431/0xa70
 __x64_sys_mount+0xe2/0x120
 do_syscall_64+0x5b/0x80
 ? do_user_addr_fault+0x1e2/0x670
 ? exc_page_fault+0x70/0x170
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7fdf4e512ace

Fix it by making sure that the block range is properly validated before
used every time it changes in ext4_free_blocks() or ext4_mb_clear_bb().

Link: https://syzkaller.appspot.com/bug?id=5266d464285a03cee9dbfda7d2452a72c3c2ae7c
Reported-by: syzbot+15cd994e273307bf5cfa@syzkaller.appspotmail.com
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Cc: Tadeusz Struk <tadeusz.struk@linaro.org>
Tested-by: Tadeusz Struk <tadeusz.struk@linaro.org>
Link: https://lore.kernel.org/r/20220714165903.58260-1-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 08:45:16 +01:00
Ritesh Harjani
c3fd717b58 ext4: add strict range checks while freeing blocks
commit a00b482b82fb098956a5bed22bd7873e56f152f1 upstream.

Currently ext4_mb_clear_bb() & ext4_group_add_blocks() only checks
whether the given block ranges (which is to be freed) belongs to any FS
metadata blocks or not, of the block's respective block group.
But to detect any FS error early, it is better to add more strict
checkings in those functions which checks whether the given blocks
belongs to any critical FS metadata or not within system-zone.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/ddd9143d064774e32d6364a99667817c6e8bfdc0.1644992610.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 08:45:16 +01:00
Ritesh Harjani
65061f49a5 ext4: add ext4_sb_block_valid() refactored out of ext4_inode_block_valid()
commit 6bc6c2bdf1baca6522b8d9ba976257d722423085 upstream.

This API will be needed at places where we don't have an inode
for e.g. while freeing blocks in ext4_group_add_blocks()

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/dd34a236543ad5ae7123eeebe0cb69e6bdd44f34.1644992610.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 08:45:16 +01:00
Ritesh Harjani
9cd21f5bab ext4: refactor ext4_free_blocks() to pull out ext4_mb_clear_bb()
commit 8ac3939db99f99667b8eb670cf4baf292896e72d upstream.

ext4_free_blocks() function became too long and confusing, this patch
just pulls out the ext4_mb_clear_bb() function logic from it
which clears the block bitmap and frees it.

No functionality change in this patch

Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/22c30fbb26ba409cf8aa5f0c7912970272c459e8.1644992610.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 08:45:15 +01:00
Jan Kara
b113f90204 ext4: Fix deadlock during directory rename
[ Upstream commit 3c92792da8506a295afb6d032b4476e46f979725 ]

As lockdep properly warns, we should not be locking i_rwsem while having
transactions started as the proper lock ordering used by all directory
handling operations is i_rwsem -> transaction start. Fix the lock
ordering by moving the locking of the directory earlier in
ext4_rename().

Reported-by: syzbot+9d16c39efb5fade84574@syzkaller.appspotmail.com
Fixes: 0813299c586b ("ext4: Fix possible corruption when moving a directory")
Link: https://syzkaller.appspot.com/bug?extid=9d16c39efb5fade84574
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230301141004.15087-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-17 08:45:13 +01:00
Jan Kara
0c440f1455 ext4: Fix possible corruption when moving a directory
[ Upstream commit 0813299c586b175d7edb25f56412c54b812d0379 ]

When we are renaming a directory to a different directory, we need to
update '..' entry in the moved directory. However nothing prevents moved
directory from being modified and even converted from the inline format
to the normal format. When such race happens the rename code gets
confused and we crash. Fix the problem by locking the moved directory.

CC: stable@vger.kernel.org
Fixes: 32f7f22c0b52 ("ext4: let ext4_rename handle inline dir")
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230126112221.11866-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-17 08:45:09 +01:00
Zhihao Cheng
3f00c476da ext4: zero i_disksize when initializing the bootloader inode
commit f5361da1e60d54ec81346aee8e3d8baf1be0b762 upstream.

If the boot loader inode has never been used before, the
EXT4_IOC_SWAP_BOOT inode will initialize it, including setting the
i_size to 0.  However, if the "never before used" boot loader has a
non-zero i_size, then i_disksize will be non-zero, and the
inconsistency between i_size and i_disksize can trigger a kernel
warning:

 WARNING: CPU: 0 PID: 2580 at fs/ext4/file.c:319
 CPU: 0 PID: 2580 Comm: bb Not tainted 6.3.0-rc1-00004-g703695902cfa
 RIP: 0010:ext4_file_write_iter+0xbc7/0xd10
 Call Trace:
  vfs_write+0x3b1/0x5c0
  ksys_write+0x77/0x160
  __x64_sys_write+0x22/0x30
  do_syscall_64+0x39/0x80

Reproducer:
 1. create corrupted image and mount it:
       mke2fs -t ext4 /tmp/foo.img 200
       debugfs -wR "sif <5> size 25700" /tmp/foo.img
       mount -t ext4 /tmp/foo.img /mnt
       cd /mnt
       echo 123 > file
 2. Run the reproducer program:
       posix_memalign(&buf, 1024, 1024)
       fd = open("file", O_RDWR | O_DIRECT);
       ioctl(fd, EXT4_IOC_SWAP_BOOT);
       write(fd, buf, 1024);

Fix this by setting i_disksize as well as i_size to zero when
initiaizing the boot loader inode.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217159
Cc: stable@kernel.org
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Link: https://lore.kernel.org/r/20230308032643.641113-1-chengzhihao1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 08:45:07 +01:00
Ye Bin
a9bd94f67b ext4: fix WARNING in ext4_update_inline_data
commit 2b96b4a5d9443ca4cad58b0040be455803c05a42 upstream.

Syzbot found the following issue:
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: none.
fscrypt: AES-256-CTS-CBC using implementation "cts-cbc-aes-aesni"
fscrypt: AES-256-XTS using implementation "xts-aes-aesni"
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5071 at mm/page_alloc.c:5525 __alloc_pages+0x30a/0x560 mm/page_alloc.c:5525
Modules linked in:
CPU: 1 PID: 5071 Comm: syz-executor263 Not tainted 6.2.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:__alloc_pages+0x30a/0x560 mm/page_alloc.c:5525
RSP: 0018:ffffc90003c2f1c0 EFLAGS: 00010246
RAX: ffffc90003c2f220 RBX: 0000000000000014 RCX: 0000000000000000
RDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc90003c2f248
RBP: ffffc90003c2f2d8 R08: dffffc0000000000 R09: ffffc90003c2f220
R10: fffff52000785e49 R11: 1ffff92000785e44 R12: 0000000000040d40
R13: 1ffff92000785e40 R14: dffffc0000000000 R15: 1ffff92000785e3c
FS:  0000555556c0d300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f95d5e04138 CR3: 00000000793aa000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __alloc_pages_node include/linux/gfp.h:237 [inline]
 alloc_pages_node include/linux/gfp.h:260 [inline]
 __kmalloc_large_node+0x95/0x1e0 mm/slab_common.c:1113
 __do_kmalloc_node mm/slab_common.c:956 [inline]
 __kmalloc+0xfe/0x190 mm/slab_common.c:981
 kmalloc include/linux/slab.h:584 [inline]
 kzalloc include/linux/slab.h:720 [inline]
 ext4_update_inline_data+0x236/0x6b0 fs/ext4/inline.c:346
 ext4_update_inline_dir fs/ext4/inline.c:1115 [inline]
 ext4_try_add_inline_entry+0x328/0x990 fs/ext4/inline.c:1307
 ext4_add_entry+0x5a4/0xeb0 fs/ext4/namei.c:2385
 ext4_add_nondir+0x96/0x260 fs/ext4/namei.c:2772
 ext4_create+0x36c/0x560 fs/ext4/namei.c:2817
 lookup_open fs/namei.c:3413 [inline]
 open_last_lookups fs/namei.c:3481 [inline]
 path_openat+0x12ac/0x2dd0 fs/namei.c:3711
 do_filp_open+0x264/0x4f0 fs/namei.c:3741
 do_sys_openat2+0x124/0x4e0 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_openat fs/open.c:1342 [inline]
 __se_sys_openat fs/open.c:1337 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1337
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Above issue happens as follows:
ext4_iget
   ext4_find_inline_data_nolock ->i_inline_off=164 i_inline_size=60
ext4_try_add_inline_entry
   __ext4_mark_inode_dirty
      ext4_expand_extra_isize_ea ->i_extra_isize=32 s_want_extra_isize=44
         ext4_xattr_shift_entries
	 ->after shift i_inline_off is incorrect, actually is change to 176
ext4_try_add_inline_entry
  ext4_update_inline_dir
    get_max_inline_xattr_value_size
      if (EXT4_I(inode)->i_inline_off)
	entry = (struct ext4_xattr_entry *)((void *)raw_inode +
			EXT4_I(inode)->i_inline_off);
        free += EXT4_XATTR_SIZE(le32_to_cpu(entry->e_value_size));
	->As entry is incorrect, then 'free' may be negative
   ext4_update_inline_data
      value = kzalloc(len, GFP_NOFS);
      -> len is unsigned int, maybe very large, then trigger warning when
         'kzalloc()'

To resolve the above issue we need to update 'i_inline_off' after
'ext4_xattr_shift_entries()'.  We do not need to set
EXT4_STATE_MAY_INLINE_DATA flag here, since ext4_mark_inode_dirty()
already sets this flag if needed.  Setting EXT4_STATE_MAY_INLINE_DATA
when it is needed may trigger a BUG_ON in ext4_writepages().

Reported-by: syzbot+d30838395804afc2fa6f@syzkaller.appspotmail.com
Cc: stable@kernel.org
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230307015253.2232062-3-yebin@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 08:45:07 +01:00
Ye Bin
d72a6c3139 ext4: move where set the MAY_INLINE_DATA flag is set
commit 1dcdce5919115a471bf4921a57f20050c545a236 upstream.

The only caller of ext4_find_inline_data_nolock() that needs setting of
EXT4_STATE_MAY_INLINE_DATA flag is ext4_iget_extra_inode().  In
ext4_write_inline_data_end() we just need to update inode->i_inline_off.
Since we are going to add one more caller that does not need to set
EXT4_STATE_MAY_INLINE_DATA, just move setting of EXT4_STATE_MAY_INLINE_DATA
out to ext4_iget_extra_inode().

Signed-off-by: Ye Bin <yebin10@huawei.com>
Cc: stable@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230307015253.2232062-2-yebin@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 08:45:06 +01:00
Darrick J. Wong
1d2366624b ext4: fix another off-by-one fsmap error on 1k block filesystems
commit c993799baf9c5861f8df91beb80e1611b12efcbd upstream.

Apparently syzbot figured out that issuing this FSMAP call:

struct fsmap_head cmd = {
	.fmh_count	= ...;
	.fmh_keys	= {
		{ .fmr_device = /* ext4 dev */, .fmr_physical = 0, },
		{ .fmr_device = /* ext4 dev */, .fmr_physical = 0, },
	},
...
};
ret = ioctl(fd, FS_IOC_GETFSMAP, &cmd);

Produces this crash if the underlying filesystem is a 1k-block ext4
filesystem:

kernel BUG at fs/ext4/ext4.h:3331!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU: 3 PID: 3227965 Comm: xfs_io Tainted: G        W  O       6.2.0-rc8-achx
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:ext4_mb_load_buddy_gfp+0x47c/0x570 [ext4]
RSP: 0018:ffffc90007c03998 EFLAGS: 00010246
RAX: ffff888004978000 RBX: ffffc90007c03a20 RCX: ffff888041618000
RDX: 0000000000000000 RSI: 00000000000005a4 RDI: ffffffffa0c99b11
RBP: ffff888012330000 R08: ffffffffa0c2b7d0 R09: 0000000000000400
R10: ffffc90007c03950 R11: 0000000000000000 R12: 0000000000000001
R13: 00000000ffffffff R14: 0000000000000c40 R15: ffff88802678c398
FS:  00007fdf2020c880(0000) GS:ffff88807e100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd318a5fe8 CR3: 000000007f80f001 CR4: 00000000001706e0
Call Trace:
 <TASK>
 ext4_mballoc_query_range+0x4b/0x210 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80]
 ext4_getfsmap_datadev+0x713/0x890 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80]
 ext4_getfsmap+0x2b7/0x330 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80]
 ext4_ioc_getfsmap+0x153/0x2b0 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80]
 __ext4_ioctl+0x2a7/0x17e0 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80]
 __x64_sys_ioctl+0x82/0xa0
 do_syscall_64+0x2b/0x80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7fdf20558aff
RSP: 002b:00007ffd318a9e30 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000000200c0 RCX: 00007fdf20558aff
RDX: 00007fdf1feb2010 RSI: 00000000c0c0583b RDI: 0000000000000003
RBP: 00005625c0634be0 R08: 00005625c0634c40 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdf1feb2010
R13: 00005625be70d994 R14: 0000000000000800 R15: 0000000000000000

For GETFSMAP calls, the caller selects a physical block device by
writing its block number into fsmap_head.fmh_keys[01].fmr_device.
To query mappings for a subrange of the device, the starting byte of the
range is written to fsmap_head.fmh_keys[0].fmr_physical and the last
byte of the range goes in fsmap_head.fmh_keys[1].fmr_physical.

IOWs, to query what mappings overlap with bytes 3-14 of /dev/sda, you'd
set the inputs as follows:

	fmh_keys[0] = { .fmr_device = major(8, 0), .fmr_physical = 3},
	fmh_keys[1] = { .fmr_device = major(8, 0), .fmr_physical = 14},

Which would return you whatever is mapped in the 12 bytes starting at
physical offset 3.

The crash is due to insufficient range validation of keys[1] in
ext4_getfsmap_datadev.  On 1k-block filesystems, block 0 is not part of
the filesystem, which means that s_first_data_block is nonzero.
ext4_get_group_no_and_offset subtracts this quantity from the blocknr
argument before cracking it into a group number and a block number
within a group.  IOWs, block group 0 spans blocks 1-8192 (1-based)
instead of 0-8191 (0-based) like what happens with larger blocksizes.

The net result of this encoding is that blocknr < s_first_data_block is
not a valid input to this function.  The end_fsb variable is set from
the keys that are copied from userspace, which means that in the above
example, its value is zero.  That leads to an underflow here:

	blocknr = blocknr - le32_to_cpu(es->s_first_data_block);

The division then operates on -1:

	offset = do_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb)) >>
		EXT4_SB(sb)->s_cluster_bits;

Leaving an impossibly large group number (2^32-1) in blocknr.
ext4_getfsmap_check_keys checked that keys[0].fmr_physical and
keys[1].fmr_physical are in increasing order, but
ext4_getfsmap_datadev adjusts keys[0].fmr_physical to be at least
s_first_data_block.  This implies that we have to check it again after
the adjustment, which is the piece that I forgot.

Reported-by: syzbot+6be2b977c89f79b6b153@syzkaller.appspotmail.com
Fixes: 4a4956249dac ("ext4: fix off-by-one fsmap error on 1k block filesystems")
Link: https://syzkaller.appspot.com/bug?id=79d5768e9bfe362911ac1a5057a36fc6b5c30002
Cc: stable@vger.kernel.org
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/Y+58NPTH7VNGgzdd@magnolia
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 08:45:06 +01:00
Eric Whitney
8706c972fc ext4: fix RENAME_WHITEOUT handling for inline directories
commit c9f62c8b2dbf7240536c0cc9a4529397bb8bf38e upstream.

A significant number of xfstests can cause ext4 to log one or more
warning messages when they are run on a test file system where the
inline_data feature has been enabled.  An example:

"EXT4-fs warning (device vdc): ext4_dirblock_csum_set:425: inode
 #16385: comm fsstress: No space for directory leaf checksum. Please
run e2fsck -D."

The xfstests include: ext4/057, 058, and 307; generic/013, 051, 068,
070, 076, 078, 083, 232, 269, 270, 390, 461, 475, 476, 482, 579, 585,
589, 626, 631, and 650.

In this situation, the warning message indicates a bug in the code that
performs the RENAME_WHITEOUT operation on a directory entry that has
been stored inline.  It doesn't detect that the directory is stored
inline, and incorrectly attempts to compute a dirent block checksum on
the whiteout inode when creating it.  This attempt fails as a result
of the integrity checking in get_dirent_tail (usually due to a failure
to match the EXT4_FT_DIR_CSUM magic cookie), and the warning message
is then emitted.

Fix this by simply collecting the inlined data state at the time the
search for the source directory entry is performed.  Existing code
handles the rest, and this is sufficient to eliminate all spurious
warning messages produced by the tests above.  Go one step further
and do the same in the code that resets the source directory entry in
the event of failure.  The inlined state should be present in the
"old" struct, but given the possibility of a race there's no harm
in taking a conservative approach and getting that information again
since the directory entry is being reread anyway.

Fixes: b7ff91fd030d ("ext4: find old entry again if failed to rename whiteout")
Cc: stable@kernel.org
Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230210173244.679890-1-enwlinux@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 08:45:06 +01:00
Eric Biggers
d0632ff49b ext4: fix cgroup writeback accounting with fs-layer encryption
commit ffec85d53d0f39ee4680a2cf0795255e000e1feb upstream.

When writing a page from an encrypted file that is using
filesystem-layer encryption (not inline encryption), ext4 encrypts the
pagecache page into a bounce page, then writes the bounce page.

It also passes the bounce page to wbc_account_cgroup_owner().  That's
incorrect, because the bounce page is a newly allocated temporary page
that doesn't have the memory cgroup of the original pagecache page.
This makes wbc_account_cgroup_owner() not account the I/O to the owner
of the pagecache page as it should.

Fix this by always passing the pagecache page to
wbc_account_cgroup_owner().

Fixes: 001e4a8775f6 ("ext4: implement cgroup writeback support")
Cc: stable@vger.kernel.org
Reported-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230203005503.141557-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 08:45:06 +01:00
Jun Nie
0dc0fa313b ext4: refuse to create ea block when umounted
commit f31173c19901a96bb2ebf6bcfec8a08df7095c91 upstream.

The ea block expansion need to access s_root while it is
already set as NULL when umount is triggered. Refuse this
request to avoid panic.

Reported-by: syzbot+2dacb8f015bf1420155f@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=3613786cb88c93aa1c6a279b1df6a7b201347d08
Link: https://lore.kernel.org/r/20230103014517.495275-3-jun.nie@linaro.org
Cc: stable@kernel.org
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-11 16:40:01 +01:00
Jun Nie
d738789ae9 ext4: optimize ea_inode block expansion
commit 1e9d62d252812575ded7c620d8fc67c32ff06c16 upstream.

Copy ea data from inode entry when expanding ea block if possible.
Then remove the ea entry if expansion success. Thus memcpy to a
temporary buffer may be avoided.

If the expansion fails, we do not need to recovery the removed ea
entry neither in this way.

Reported-by: syzbot+2dacb8f015bf1420155f@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=3613786cb88c93aa1c6a279b1df6a7b201347d08
Link: https://lore.kernel.org/r/20230103014517.495275-2-jun.nie@linaro.org
Cc: stable@kernel.org
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-11 16:40:01 +01:00
Kees Cook
1ba10d3640 ext4: Fix function prototype mismatch for ext4_feat_ktype
commit 118901ad1f25d2334255b3d50512fa20591531cd upstream.

With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG),
indirect call targets are validated against the expected function
pointer prototype to make sure the call target is valid to help mitigate
ROP attacks. If they are not identical, there is a failure at run time,
which manifests as either a kernel panic or thread getting killed.

ext4_feat_ktype was setting the "release" handler to "kfree", which
doesn't have a matching function prototype. Add a simple wrapper
with the correct prototype.

This was found as a result of Clang's new -Wcast-function-type-strict
flag, which is more sensitive than the simpler -Wcast-function-type,
which only checks for type width mismatches.

Note that this code is only reached when ext4 is a loadable module and
it is being unloaded:

 CFI failure at kobject_put+0xbb/0x1b0 (target: kfree+0x0/0x180; expected type: 0x7c4aa698)
 ...
 RIP: 0010:kobject_put+0xbb/0x1b0
 ...
 Call Trace:
  <TASK>
  ext4_exit_sysfs+0x14/0x60 [ext4]
  cleanup_module+0x67/0xedb [ext4]

Fixes: b99fee58a20a ("ext4: create ext4_feat kobject dynamically")
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: stable@vger.kernel.org
Build-tested-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20230103234616.never.915-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20230104210908.gonna.388-kees@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-25 11:55:04 +01:00
Ye Bin
091f85db4c ext4: fix uninititialized value in 'ext4_evict_inode'
[ Upstream commit 7ea71af94eaaaf6d9aed24bc94a05b977a741cb9 ]

Syzbot found the following issue:
=====================================================
BUG: KMSAN: uninit-value in ext4_evict_inode+0xdd/0x26b0 fs/ext4/inode.c:180
 ext4_evict_inode+0xdd/0x26b0 fs/ext4/inode.c:180
 evict+0x365/0x9a0 fs/inode.c:664
 iput_final fs/inode.c:1747 [inline]
 iput+0x985/0xdd0 fs/inode.c:1773
 __ext4_new_inode+0xe54/0x7ec0 fs/ext4/ialloc.c:1361
 ext4_mknod+0x376/0x840 fs/ext4/namei.c:2844
 vfs_mknod+0x79d/0x830 fs/namei.c:3914
 do_mknodat+0x47d/0xaa0
 __do_sys_mknodat fs/namei.c:3992 [inline]
 __se_sys_mknodat fs/namei.c:3989 [inline]
 __ia32_sys_mknodat+0xeb/0x150 fs/namei.c:3989
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

Uninit was created at:
 __alloc_pages+0x9f1/0xe80 mm/page_alloc.c:5578
 alloc_pages+0xaae/0xd80 mm/mempolicy.c:2285
 alloc_slab_page mm/slub.c:1794 [inline]
 allocate_slab+0x1b5/0x1010 mm/slub.c:1939
 new_slab mm/slub.c:1992 [inline]
 ___slab_alloc+0x10c3/0x2d60 mm/slub.c:3180
 __slab_alloc mm/slub.c:3279 [inline]
 slab_alloc_node mm/slub.c:3364 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc_lru+0x6f3/0xb30 mm/slub.c:3429
 alloc_inode_sb include/linux/fs.h:3117 [inline]
 ext4_alloc_inode+0x5f/0x860 fs/ext4/super.c:1321
 alloc_inode+0x83/0x440 fs/inode.c:259
 new_inode_pseudo fs/inode.c:1018 [inline]
 new_inode+0x3b/0x430 fs/inode.c:1046
 __ext4_new_inode+0x2a7/0x7ec0 fs/ext4/ialloc.c:959
 ext4_mkdir+0x4d5/0x1560 fs/ext4/namei.c:2992
 vfs_mkdir+0x62a/0x870 fs/namei.c:4035
 do_mkdirat+0x466/0x7b0 fs/namei.c:4060
 __do_sys_mkdirat fs/namei.c:4075 [inline]
 __se_sys_mkdirat fs/namei.c:4073 [inline]
 __ia32_sys_mkdirat+0xc4/0x120 fs/namei.c:4073
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

CPU: 1 PID: 4625 Comm: syz-executor.2 Not tainted 6.1.0-rc4-syzkaller-62821-gcb231e2f67ec #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
=====================================================

Now, 'ext4_alloc_inode()' didn't init 'ei->i_flags'. If new inode failed
before set 'ei->i_flags' in '__ext4_new_inode()', then do 'iput()'. As after
6bc0d63dad7f commit will access 'ei->i_flags' in 'ext4_evict_inode()' which
will lead to access uninit-value.
To solve above issue just init 'ei->i_flags' in 'ext4_alloc_inode()'.

Reported-by: syzbot+57b25da729eb0b88177d@syzkaller.appspotmail.com
Signed-off-by: Ye Bin <yebin10@huawei.com>
Fixes: 6bc0d63dad7f ("ext4: remove EA inode entry from mbcache on inode eviction")
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20221117073603.2598882-1-yebin@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18 11:44:57 +01:00
Eric Biggers
23ad034760 ext4: don't set up encryption key during jbd2 transaction
commit 4c0d5778385cb3618ff26a561ce41de2b7d9de70 upstream.

Commit a80f7fcf1867 ("ext4: fixup ext4_fc_track_* functions' signature")
extended the scope of the transaction in ext4_unlink() too far, making
it include the call to ext4_find_entry().  However, ext4_find_entry()
can deadlock when called from within a transaction because it may need
to set up the directory's encryption key.

Fix this by restoring the transaction to its original scope.

Reported-by: syzbot+1a748d0007eeac3ab079@syzkaller.appspotmail.com
Fixes: a80f7fcf1867 ("ext4: fixup ext4_fc_track_* functions' signature")
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20221106224841.279231-3-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-14 10:16:51 +01:00
Eric Biggers
d9ff5ad203 ext4: disable fast-commit of encrypted dir operations
commit 0fbcb5251fc81b58969b272c4fb7374a7b922e3e upstream.

fast-commit of create, link, and unlink operations in encrypted
directories is completely broken because the unencrypted filenames are
being written to the fast-commit journal instead of the encrypted
filenames.  These operations can't be replayed, as encryption keys
aren't present at journal replay time.  It is also an information leak.

Until if/when we can get this working properly, make encrypted directory
operations ineligible for fast-commit.

Note that fast-commit operations on encrypted regular files continue to
be allowed, as they seem to work.

Fixes: aa75f4d3daae ("ext4: main fast-commit commit path")
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20221106224841.279231-2-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-14 10:16:51 +01:00
Eric Biggers
a41d63f204 ext4: don't allow journal inode to have encrypt flag
commit 105c78e12468413e426625831faa7db4284e1fec upstream.

Mounting a filesystem whose journal inode has the encrypt flag causes a
NULL dereference in fscrypt_limit_io_blocks() when the 'inlinecrypt'
mount option is used.

The problem is that when jbd2_journal_init_inode() calls bmap(), it
eventually finds its way into ext4_iomap_begin(), which calls
fscrypt_limit_io_blocks().  fscrypt_limit_io_blocks() requires that if
the inode is encrypted, then its encryption key must already be set up.
That's not the case here, since the journal inode is never "opened" like
a normal file would be.  Hence the crash.

A reproducer is:

    mkfs.ext4 -F /dev/vdb
    debugfs -w /dev/vdb -R "set_inode_field <8> flags 0x80808"
    mount /dev/vdb /mnt -o inlinecrypt

To fix this, make ext4 consider journal inodes with the encrypt flag to
be invalid.  (Note, maybe other flags should be rejected on the journal
inode too.  For now, this is just the minimal fix for the above issue.)

I've marked this as fixing the commit that introduced the call to
fscrypt_limit_io_blocks(), since that's what made an actual crash start
being possible.  But this fix could be applied to any version of ext4
that supports the encrypt feature.

Reported-by: syzbot+ba9dac45bc76c490b7c3@syzkaller.appspotmail.com
Fixes: 38ea50daa7a4 ("ext4: support direct I/O with fscrypt using blk-crypto")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20221102053312.189962-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-14 10:16:50 +01:00
Jan Kara
1be16a0c2f ext4: fix deadlock due to mbcache entry corruption
[ Upstream commit a44e84a9b7764c72896f7241a0ec9ac7e7ef38dd ]

When manipulating xattr blocks, we can deadlock infinitely looping
inside ext4_xattr_block_set() where we constantly keep finding xattr
block for reuse in mbcache but we are unable to reuse it because its
reference count is too big. This happens because cache entry for the
xattr block is marked as reusable (e_reusable set) although its
reference count is too big. When this inconsistency happens, this
inconsistent state is kept indefinitely and so ext4_xattr_block_set()
keeps retrying indefinitely.

The inconsistent state is caused by non-atomic update of e_reusable bit.
e_reusable is part of a bitfield and e_reusable update can race with
update of e_referenced bit in the same bitfield resulting in loss of one
of the updates. Fix the problem by using atomic bitops instead.

This bug has been around for many years, but it became *much* easier
to hit after commit 65f8b80053a1 ("ext4: fix race when reusing xattr
blocks").

Cc: stable@vger.kernel.org
Fixes: 6048c64b2609 ("mbcache: add reusable flag to cache entries")
Fixes: 65f8b80053a1 ("ext4: fix race when reusing xattr blocks")
Reported-and-tested-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Reported-by: Thilo Fromm <t-lo@linux.microsoft.com>
Link: https://lore.kernel.org/r/c77bf00f-4618-7149-56f1-b8d1664b9d07@linux.microsoft.com/
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20221123193950.16758-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:44 +01:00