291 Commits

Author SHA1 Message Date
Ivan Orlov
acd5f476c1 nbd: Fix debugfs_create_dir error checking
[ Upstream commit 4913cfcf014c95f0437db2df1734472fd3e15098 ]

The debugfs_create_dir function returns ERR_PTR in case of error, and the
only correct way to check if an error occurred is 'IS_ERR' inline function.
This patch will replace the null-comparison with IS_ERR.

Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20230512130533.98709-1-ivan.orlov0322@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-09 10:28:56 +02:00
Shigeru Yoshida
3575949513 nbd: Fix hung when signal interrupts nbd_start_device_ioctl()
[ Upstream commit 1de7c3cf48fc41cd95adb12bd1ea9033a917798a ]

syzbot reported hung task [1].  The following program is a simplified
version of the reproducer:

int main(void)
{
	int sv[2], fd;

	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) < 0)
		return 1;
	if ((fd = open("/dev/nbd0", 0)) < 0)
		return 1;
	if (ioctl(fd, NBD_SET_SIZE_BLOCKS, 0x81) < 0)
		return 1;
	if (ioctl(fd, NBD_SET_SOCK, sv[0]) < 0)
		return 1;
	if (ioctl(fd, NBD_DO_IT) < 0)
		return 1;
	return 0;
}

When signal interrupt nbd_start_device_ioctl() waiting the condition
atomic_read(&config->recv_threads) == 0, the task can hung because it
waits the completion of the inflight IOs.

This patch fixes the issue by clearing queue, not just shutdown, when
signal interrupt nbd_start_device_ioctl().

Link: https://syzkaller.appspot.com/bug?id=7d89a3ffacd2b83fdd39549bc4d8e0a89ef21239 [1]
Reported-by: syzbot+38e6c55d4969a14c1534@syzkaller.appspotmail.com
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20220907163502.577561-1-syoshida@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 13:22:56 +02:00
Yu Kuai
69893d6d7f nbd: fix io hung while disconnecting device
[ Upstream commit 09dadb5985023e27d4740ebd17e6fea4640110e5 ]

In our tests, "qemu-nbd" triggers a io hung:

INFO: task qemu-nbd:11445 blocked for more than 368 seconds.
      Not tainted 5.18.0-rc3-next-20220422-00003-g2176915513ca #884
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:qemu-nbd        state:D stack:    0 pid:11445 ppid:     1 flags:0x00000000
Call Trace:
 <TASK>
 __schedule+0x480/0x1050
 ? _raw_spin_lock_irqsave+0x3e/0xb0
 schedule+0x9c/0x1b0
 blk_mq_freeze_queue_wait+0x9d/0xf0
 ? ipi_rseq+0x70/0x70
 blk_mq_freeze_queue+0x2b/0x40
 nbd_add_socket+0x6b/0x270 [nbd]
 nbd_ioctl+0x383/0x510 [nbd]
 blkdev_ioctl+0x18e/0x3e0
 __x64_sys_ioctl+0xac/0x120
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fd8ff706577
RSP: 002b:00007fd8fcdfebf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000040000000 RCX: 00007fd8ff706577
RDX: 000000000000000d RSI: 000000000000ab00 RDI: 000000000000000f
RBP: 000000000000000f R08: 000000000000fbe8 R09: 000055fe497c62b0
R10: 00000002aff20000 R11: 0000000000000246 R12: 000000000000006d
R13: 0000000000000000 R14: 00007ffe82dc5e70 R15: 00007fd8fcdff9c0

"qemu-ndb -d" will call ioctl 'NBD_DISCONNECT' first, however, following
message was found:

block nbd0: Send disconnect failed -32

Which indicate that something is wrong with the server. Then,
"qemu-nbd -d" will call ioctl 'NBD_CLEAR_SOCK', however ioctl can't clear
requests after commit 2516ab1543fd("nbd: only clear the queue on device
teardown"). And in the meantime, request can't complete through timeout
because nbd_xmit_timeout() will always return 'BLK_EH_RESET_TIMER', which
means such request will never be completed in this situation.

Now that the flag 'NBD_CMD_INFLIGHT' can make sure requests won't
complete multiple times, switch back to call nbd_clear_sock() in
nbd_clear_sock_ioctl(), so that inflight requests can be cleared.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20220521073749.3146892-5-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:12:01 +02:00
Yu Kuai
8a7da4ced2 nbd: fix race between nbd_alloc_config() and module removal
[ Upstream commit c55b2b983b0fa012942c3eb16384b2b722caa810 ]

When nbd module is being removing, nbd_alloc_config() may be
called concurrently by nbd_genl_connect(), although try_module_get()
will return false, but nbd_alloc_config() doesn't handle it.

The race may lead to the leak of nbd_config and its related
resources (e.g, recv_workq) and oops in nbd_read_stat() due
to the unload of nbd module as shown below:

  BUG: kernel NULL pointer dereference, address: 0000000000000040
  Oops: 0000 [#1] SMP PTI
  CPU: 5 PID: 13840 Comm: kworker/u17:33 Not tainted 5.14.0+ #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
  Workqueue: knbd16-recv recv_work [nbd]
  RIP: 0010:nbd_read_stat.cold+0x130/0x1a4 [nbd]
  Call Trace:
   recv_work+0x3b/0xb0 [nbd]
   process_one_work+0x1ed/0x390
   worker_thread+0x4a/0x3d0
   kthread+0x12a/0x150
   ret_from_fork+0x22/0x30

Fixing it by checking the return value of try_module_get()
in nbd_alloc_config(). As nbd_alloc_config() may return ERR_PTR(-ENODEV),
assign nbd->config only when nbd_alloc_config() succeeds to ensure
the value of nbd->config is binary (valid or NULL).

Also adding a debug message to check the reference counter
of nbd_config during module removal.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20220521073749.3146892-3-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:12:01 +02:00
Yu Kuai
1be608e1ee nbd: call genl_unregister_family() first in nbd_cleanup()
[ Upstream commit 06c4da89c24e7023ea448cadf8e9daf06a0aae6e ]

Otherwise there may be race between module removal and the handling of
netlink command, which can lead to the oops as shown below:

  BUG: kernel NULL pointer dereference, address: 0000000000000098
  Oops: 0002 [#1] SMP PTI
  CPU: 1 PID: 31299 Comm: nbd-client Tainted: G            E     5.14.0-rc4
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
  RIP: 0010:down_write+0x1a/0x50
  Call Trace:
   start_creating+0x89/0x130
   debugfs_create_dir+0x1b/0x130
   nbd_start_device+0x13d/0x390 [nbd]
   nbd_genl_connect+0x42f/0x748 [nbd]
   genl_family_rcv_msg_doit.isra.0+0xec/0x150
   genl_rcv_msg+0xe5/0x1e0
   netlink_rcv_skb+0x55/0x100
   genl_rcv+0x29/0x40
   netlink_unicast+0x1a8/0x250
   netlink_sendmsg+0x21b/0x430
   ____sys_sendmsg+0x2a4/0x2d0
   ___sys_sendmsg+0x81/0xc0
   __sys_sendmsg+0x62/0xb0
   __x64_sys_sendmsg+0x1f/0x30
   do_syscall_64+0x3b/0xc0
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  Modules linked in: nbd(E-)

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20220521073749.3146892-2-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:12:01 +02:00
Xie Yongji
9d1764b926 nbd: Fix hung on disconnect request if socket is closed before
[ Upstream commit 491bf8f236fdeec698fa6744993f1ecf3fafd1a5 ]

When userspace closes the socket before sending a disconnect
request, the following I/O requests will be blocked in
wait_for_reconnect() until dead timeout. This will cause the
following disconnect request also hung on blk_mq_quiesce_queue().
That means we have no way to disconnect a nbd device if there
are some I/O requests waiting for reconnecting until dead timeout.
It's not expected. So let's wake up the thread waiting for
reconnecting directly when a disconnect request is sent.

Reported-by: Xu Jianhai <zero.xu@bytedance.com>
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20220322080639.142-1-xieyongji@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:11:28 +02:00
Greg Kroah-Hartman
541e757944 Revert "block: nbd: add sanity check for first_minor"
This reverts commit b3fa499d72a0db612f12645265a36751955c0037 which is
commit b1a811633f7321cf1ae2bb76a66805b7720e44c9 upstream.

The backport of this is reported to be causing some problems, so revert
this for now until they are worked out.

Link: https://lore.kernel.org/r/CACPK8XfUWoOHr-0RwRoYoskia4fbAbZ7DYf5wWBnv6qUnGq18w@mail.gmail.com
Reported-by: Joel Stanley <joel@jms.id.au>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Pavel Skripkin <paskripkin@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-16 12:56:13 +02:00
Pavel Skripkin
b3fa499d72 block: nbd: add sanity check for first_minor
[ Upstream commit b1a811633f7321cf1ae2bb76a66805b7720e44c9 ]

Syzbot hit WARNING in internal_create_group(). The problem was in
too big disk->first_minor.

disk->first_minor is initialized by value, which comes from userspace
and there wasn't any sanity checks about value correctness. It can cause
duplicate creation of sysfs files/links, because disk->first_minor will
be passed to MKDEV() which causes truncation to byte. Since maximum
minor value is 0xff, let's check if first_minor is correct minor number.

NOTE: the root case of the reported warning was in wrong error handling
in register_disk(), but we can avoid passing knowingly wrong values to
sysfs API, because sysfs error messages can confuse users. For example:
user passed 1048576 as index, but sysfs complains about duplicate
creation of /dev/block/43:0. It's not obvious how 1048576 becomes 0.
Log and reproducer for above example can be found on syzkaller bug
report page.

Link: https://syzkaller.appspot.com/bug?id=03c2ae9146416edf811958d5fd7acfab75b143d1
Fixes: b0d9111a2d53 ("nbd: use an idr to keep track of nbd devices")
Reported-by: syzbot+9937dc42271cd87d4b98@syzkaller.appspotmail.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15 09:47:29 +02:00
Xie Yongji
b74145d858 nbd: Aovid double completion of a request
[ Upstream commit cddce01160582a5f52ada3da9626c052d852ec42 ]

There is a race between iterating over requests in
nbd_clear_que() and completing requests in recv_work(),
which can lead to double completion of a request.

To fix it, flush the recv worker before iterating over
the requests and don't abort the completed request
while iterating.

Fixes: 96d97e17828f ("nbd: clear_sock on netlink disconnect")
Reported-by: Jiang Yadong <jiangyadong@bytedance.com>
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20210813151330.96-1-xieyongji@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-18 08:57:01 +02:00
Sun Ke
1c4962df93 nbd: Fix NULL pointer in flush_workqueue
[ Upstream commit 79ebe9110fa458d58f1fceb078e2068d7ad37390 ]

Open /dev/nbdX first, the config_refs will be 1 and
the pointers in nbd_device are still null. Disconnect
/dev/nbdX, then reference a null recv_workq. The
protection by config_refs in nbd_genl_disconnect is useless.

[  656.366194] BUG: kernel NULL pointer dereference, address: 0000000000000020
[  656.368943] #PF: supervisor write access in kernel mode
[  656.369844] #PF: error_code(0x0002) - not-present page
[  656.370717] PGD 10cc87067 P4D 10cc87067 PUD 1074b4067 PMD 0
[  656.371693] Oops: 0002 [#1] SMP
[  656.372242] CPU: 5 PID: 7977 Comm: nbd-client Not tainted 5.11.0-rc5-00040-g76c057c84d28 #1
[  656.373661] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
[  656.375904] RIP: 0010:mutex_lock+0x29/0x60
[  656.376627] Code: 00 0f 1f 44 00 00 55 48 89 fd 48 83 05 6f d7 fe 08 01 e8 7a c3 ff ff 48 83 05 6a d7 fe 08 01 31 c0 65 48 8b 14 25 00 6d 01 00 <f0> 48 0f b1 55 d
[  656.378934] RSP: 0018:ffffc900005eb9b0 EFLAGS: 00010246
[  656.379350] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[  656.379915] RDX: ffff888104cf2600 RSI: ffffffffaae8f452 RDI: 0000000000000020
[  656.380473] RBP: 0000000000000020 R08: 0000000000000000 R09: ffff88813bd6b318
[  656.381039] R10: 00000000000000c7 R11: fefefefefefefeff R12: ffff888102710b40
[  656.381599] R13: ffffc900005eb9e0 R14: ffffffffb2930680 R15: ffff88810770ef00
[  656.382166] FS:  00007fdf117ebb40(0000) GS:ffff88813bd40000(0000) knlGS:0000000000000000
[  656.382806] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  656.383261] CR2: 0000000000000020 CR3: 0000000100c84000 CR4: 00000000000006e0
[  656.383819] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  656.384370] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  656.384927] Call Trace:
[  656.385111]  flush_workqueue+0x92/0x6c0
[  656.385395]  nbd_disconnect_and_put+0x81/0xd0
[  656.385716]  nbd_genl_disconnect+0x125/0x2a0
[  656.386034]  genl_family_rcv_msg_doit.isra.0+0x102/0x1b0
[  656.386422]  genl_rcv_msg+0xfc/0x2b0
[  656.386685]  ? nbd_ioctl+0x490/0x490
[  656.386954]  ? genl_family_rcv_msg_doit.isra.0+0x1b0/0x1b0
[  656.387354]  netlink_rcv_skb+0x62/0x180
[  656.387638]  genl_rcv+0x34/0x60
[  656.387874]  netlink_unicast+0x26d/0x590
[  656.388162]  netlink_sendmsg+0x398/0x6c0
[  656.388451]  ? netlink_rcv_skb+0x180/0x180
[  656.388750]  ____sys_sendmsg+0x1da/0x320
[  656.389038]  ? ____sys_recvmsg+0x130/0x220
[  656.389334]  ___sys_sendmsg+0x8e/0xf0
[  656.389605]  ? ___sys_recvmsg+0xa2/0xf0
[  656.389889]  ? handle_mm_fault+0x1671/0x21d0
[  656.390201]  __sys_sendmsg+0x6d/0xe0
[  656.390464]  __x64_sys_sendmsg+0x23/0x30
[  656.390751]  do_syscall_64+0x45/0x70
[  656.391017]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

To fix it, just add if (nbd->recv_workq) to nbd_disconnect_and_put().

Fixes: e9e006f5fcf2 ("nbd: fix max number of supported devs")
Signed-off-by: Sun Ke <sunke32@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20210512114331.1233964-2-sunke32@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-19 10:08:30 +02:00
Josef Bacik
4ed3162e92 nbd: handle device refs for DESTROY_ON_DISCONNECT properly
commit c9a2f90f4d6b9d42b9912f7aaf68e8d748acfffd upstream.

There exists a race where we can be attempting to create a new nbd
configuration while a previous configuration is going down, both
configured with DESTROY_ON_DISCONNECT.  Normally devices all have a
reference of 1, as they won't be cleaned up until the module is torn
down.  However with DESTROY_ON_DISCONNECT we'll make sure that there is
only 1 reference (generally) on the device for the config itself, and
then once the config is dropped, the device is torn down.

The race that exists looks like this

TASK1					TASK2
nbd_genl_connect()
  idr_find()
    refcount_inc_not_zero(nbd)
      * count is 2 here ^^
					nbd_config_put()
					  nbd_put(nbd) (count is 1)
    setup new config
      check DESTROY_ON_DISCONNECT
	put_dev = true
    if (put_dev) nbd_put(nbd)
	* free'd here ^^

In nbd_genl_connect() we assume that the nbd ref count will be 2,
however clearly that won't be true if the nbd device had been setup as
DESTROY_ON_DISCONNECT with its prior configuration.  Fix this by getting
rid of the runtime flag to check if we need to mess with the nbd device
refcount, and use the device NBD_DESTROY_ON_DISCONNECT flag to check if
we need to adjust the ref counts.  This was reported by syzkaller with
the following kasan dump

BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:71 [inline]
BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:27 [inline]
BUG: KASAN: use-after-free in refcount_dec_not_one+0x71/0x1e0 lib/refcount.c:76
Read of size 4 at addr ffff888143bf71a0 by task systemd-udevd/8451

CPU: 0 PID: 8451 Comm: systemd-udevd Not tainted 5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:230
 __kasan_report mm/kasan/report.c:396 [inline]
 kasan_report.cold+0x79/0xd5 mm/kasan/report.c:413
 check_memory_region_inline mm/kasan/generic.c:179 [inline]
 check_memory_region+0x13d/0x180 mm/kasan/generic.c:185
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 atomic_read include/asm-generic/atomic-instrumented.h:27 [inline]
 refcount_dec_not_one+0x71/0x1e0 lib/refcount.c:76
 refcount_dec_and_mutex_lock+0x19/0x140 lib/refcount.c:115
 nbd_put drivers/block/nbd.c:248 [inline]
 nbd_release+0x116/0x190 drivers/block/nbd.c:1508
 __blkdev_put+0x548/0x800 fs/block_dev.c:1579
 blkdev_put+0x92/0x570 fs/block_dev.c:1632
 blkdev_close+0x8c/0xb0 fs/block_dev.c:1640
 __fput+0x283/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x190 kernel/task_work.c:140
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fc1e92b5270
Code: 73 01 c3 48 8b 0d 38 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 59 c1 20 00 00 75 10 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ee fb ff ff 48 89 04 24
RSP: 002b:00007ffe8beb2d18 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007fc1e92b5270
RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 00007fc1ea16f710 R08: 000000000000004a R09: 0000000000000008
R10: 0000562f8cb0b2a8 R11: 0000000000000246 R12: 0000000000000000
R13: 0000562f8cb0afd0 R14: 0000000000000003 R15: 000000000000000e

Allocated by task 1:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:401 [inline]
 ____kasan_kmalloc.constprop.0+0x82/0xa0 mm/kasan/common.c:429
 kmalloc include/linux/slab.h:552 [inline]
 kzalloc include/linux/slab.h:682 [inline]
 nbd_dev_add+0x44/0x8e0 drivers/block/nbd.c:1673
 nbd_init+0x250/0x271 drivers/block/nbd.c:2394
 do_one_initcall+0x103/0x650 init/main.c:1223
 do_initcall_level init/main.c:1296 [inline]
 do_initcalls init/main.c:1312 [inline]
 do_basic_setup init/main.c:1332 [inline]
 kernel_init_freeable+0x605/0x689 init/main.c:1533
 kernel_init+0xd/0x1b8 init/main.c:1421
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Freed by task 8451:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:356
 ____kasan_slab_free+0xe1/0x110 mm/kasan/common.c:362
 kasan_slab_free include/linux/kasan.h:192 [inline]
 slab_free_hook mm/slub.c:1547 [inline]
 slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1580
 slab_free mm/slub.c:3143 [inline]
 kfree+0xdb/0x3b0 mm/slub.c:4139
 nbd_dev_remove drivers/block/nbd.c:243 [inline]
 nbd_put.part.0+0x180/0x1d0 drivers/block/nbd.c:251
 nbd_put drivers/block/nbd.c:295 [inline]
 nbd_config_put+0x6dd/0x8c0 drivers/block/nbd.c:1242
 nbd_release+0x103/0x190 drivers/block/nbd.c:1507
 __blkdev_put+0x548/0x800 fs/block_dev.c:1579
 blkdev_put+0x92/0x570 fs/block_dev.c:1632
 blkdev_close+0x8c/0xb0 fs/block_dev.c:1640
 __fput+0x283/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x190 kernel/task_work.c:140
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff888143bf7000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 416 bytes inside of
 1024-byte region [ffff888143bf7000, ffff888143bf7400)
The buggy address belongs to the page:
page:000000005238f4ce refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x143bf0
head:000000005238f4ce order:3 compound_mapcount:0 compound_pincount:0
flags: 0x57ff00000010200(slab|head)
raw: 057ff00000010200 ffffea00004b1400 0000000300000003 ffff888010c41140
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888143bf7080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888143bf7100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888143bf7180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff888143bf7200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Reported-and-tested-by: syzbot+429d3f82d757c211bff3@syzkaller.appspotmail.com
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-07 12:20:42 +01:00
Josef Bacik
587c6b75d7 nbd: freeze the queue while we're adding connections
commit b98e762e3d71e893b221f871825dc64694cfb258 upstream.

When setting up a device, we can krealloc the config->socks array to add
new sockets to the configuration.  However if we happen to get a IO
request in at this point even though we aren't setup we could hit a UAF,
as we deref config->socks without any locking, assuming that the
configuration was setup already and that ->socks is safe to access it as
we have a reference on the configuration.

But there's nothing really preventing IO from occurring at this point of
the device setup, we don't want to incur the overhead of a lock to
access ->socks when it will never change while the device is running.
To fix this UAF scenario simply freeze the queue if we are adding
sockets.  This will protect us from this particular case without adding
any additional overhead for the normal running case.

Cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-03 23:25:56 +01:00
Christoph Hellwig
81dcfdb9a0 nbd: fix a block_device refcount leak in nbd_release
[ Upstream commit 2bd645b2d3f0bacadaa6037f067538e1cd4e42ef ]

bdget_disk needs to be paired with bdput to not leak a reference
on the block device inode.

Fixes: 08ba91ee6e2c ("nbd: Add the nbd NBD_DISCONNECT_ON_CLOSE config flag.")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-18 19:20:27 +01:00
Ming Lei
95fda70d39 nbd: don't update block size after device is started
[ Upstream commit b40813ddcd6bf9f01d020804e4cb8febc480b9e4 ]

Mounted NBD device can be resized, one use case is rbd-nbd.

Fix the issue by setting up default block size, then not touch it
in nbd_size_update() any more. This kind of usage is aligned with loop
which has same use case too.

Cc: stable@vger.kernel.org
Fixes: c8a83a6b54d0 ("nbd: Use set_blocksize() to set device blocksize")
Reported-by: lining <lining2020x@163.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Jan Kara <jack@suse.cz>
Tested-by: lining <lining2020x@163.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-18 19:20:15 +01:00
Xiubo Li
742fd49cf8 nbd: make the config put is called before the notifying the waiter
[ Upstream commit 87aac3a80af5cbad93e63250e8a1e19095ba0d30 ]

There has one race case for ceph's rbd-nbd tool. When do mapping
it may fail with EBUSY from ioctl(nbd, NBD_DO_IT), but actually
the nbd device has already unmaped.

It dues to if just after the wake_up(), the recv_work() is scheduled
out and defers calling the nbd_config_put(), though the map process
has exited the "nbd->recv_task" is not cleared.

Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-05 11:43:22 +01:00
Hou Pu
c756635246 nbd: restore default timeout when setting it to zero
[ Upstream commit acb19e17c5134dd78668c429ecba5b481f038e6a ]

If we configured io timeout of nbd0 to 100s. Later after we
finished using it, we configured nbd0 again and set the io
timeout to 0. We expect it would timeout after 30 seconds
and keep retry. But in fact we could not change the timeout
when we set it to 0. the timeout is still the original 100s.

So change the timeout to default 30s when we set it to zero.
It also behaves same as commit 2da22da57348 ("nbd: fix zero
cmd timeout handling v2").

It becomes more important if we were reconfigure a nbd device
and the io timeout it set to zero. Because it could take 30s
to detect the new socket and thus io could be completed more
quickly compared to 100s.

Signed-off-by: Hou Pu <houpu@bytedance.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-09 19:12:22 +02:00
Zheng Bin
2a4c5ff12f nbd: Fix memory leak in nbd_add_socket
[ Upstream commit 579dd91ab3a5446b148e7f179b6596b270dace46 ]

When adding first socket to nbd, if nsock's allocation failed, the data
structure member "config->socks" was reallocated, but the data structure
member "config->num_connections" was not updated. A memory leak will occur
then because the function "nbd_config_put" will free "config->socks" only
when "config->num_connections" is not zero.

Fixes: 03bf73c315ed ("nbd: prevent memory leak")
Reported-by: syzbot+934037347002901b8d2a@syzkaller.appspotmail.com
Signed-off-by: Zheng Bin <zhengbin13@huawei.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-16 08:16:40 +02:00
Sun Ke
25cbba5d4e nbd: add a flush_workqueue in nbd_start_device
[ Upstream commit 5c0dd228b5fc30a3b732c7ae2657e0161ec7ed80 ]

When kzalloc fail, may cause trying to destroy the
workqueue from inside the workqueue.

If num_connections is m (2 < m), and NO.1 ~ NO.n
(1 < n < m) kzalloc are successful. The NO.(n + 1)
failed. Then, nbd_start_device will return ENOMEM
to nbd_start_device_ioctl, and nbd_start_device_ioctl
will return immediately without running flush_workqueue.
However, we still have n recv threads. If nbd_release
run first, recv threads may have to drop the last
config_refs and try to destroy the workqueue from
inside the workqueue.

To fix it, add a flush_workqueue in nbd_start_device.

Fixes: e9e006f5fcf2 ("nbd: fix max number of supported devs")
Signed-off-by: Sun Ke <sunke32@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24 08:36:31 +01:00
Mike Christie
b3ead320dc nbd: fix shutdown and recv work deadlock v2
commit 1c05839aa973cfae8c3db964a21f9c0eef8fcc21 upstream.

This fixes a regression added with:

commit e9e006f5fcf2bab59149cb38a48a4817c1b538b4
Author: Mike Christie <mchristi@redhat.com>
Date:   Sun Aug 4 14:10:06 2019 -0500

    nbd: fix max number of supported devs

where we can deadlock during device shutdown. The problem occurs if
the recv_work's nbd_config_put occurs after nbd_start_device_ioctl has
returned and the userspace app has droppped its reference via closing
the device and running nbd_release. The recv_work nbd_config_put call
would then drop the refcount to zero and try to destroy the config which
would try to do destroy_workqueue from the recv work.

This patch just has nbd_start_device_ioctl do a flush_workqueue when it
wakes so we know after the ioctl returns running works have exited. This
also fixes a possible race where we could try to reuse the device while
old recv_works are still running.

Cc: stable@vger.kernel.org
Fixes: e9e006f5fcf2 ("nbd: fix max number of supported devs")
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-31 16:46:34 +01:00
Navid Emamdoost
abf404dfa5 nbd: prevent memory leak
commit 03bf73c315edca28f47451913177e14cd040a216 upstream.

In nbd_add_socket when krealloc succeeds, if nsock's allocation fail the
reallocted memory is leak. The correct behaviour should be assigning the
reallocted memory to config->socks right after success.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-29 10:09:47 +01:00
Sun Ke
dff10bbea4 nbd:fix memory leak in nbd_get_socket()
Before returning NULL, put the sock first.

Cc: stable@vger.kernel.org
Fixes: cf1b2326b734 ("nbd: verify socket is supported during setup")
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Sun Ke <sunke32@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-19 09:23:26 -07:00
Mike Christie
cf1b2326b7 nbd: verify socket is supported during setup
nbd requires socket families to support the shutdown method so the nbd
recv workqueue can be woken up from its sock_recvmsg call. If the socket
does not support the callout we will leave recv works running or get hangs
later when the device or module is removed.

This adds a check during socket connection/reconnection to make sure the
socket being passed in supports the needed callout.

Reported-by: syzbot+24c12fa8d218ed26011a@syzkaller.appspotmail.com
Fixes: e9e006f5fcf2 ("nbd: fix max number of supported devs")
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-25 14:37:21 -06:00
Josef Bacik
7ce23e8e0a nbd: handle racing with error'ed out commands
We hit the following warning in production

print_req_error: I/O error, dev nbd0, sector 7213934408 flags 80700
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 25 PID: 32407 at lib/refcount.c:190 refcount_sub_and_test_checked+0x53/0x60
Workqueue: knbd-recv recv_work [nbd]
RIP: 0010:refcount_sub_and_test_checked+0x53/0x60
Call Trace:
 blk_mq_free_request+0xb7/0xf0
 blk_mq_complete_request+0x62/0xf0
 recv_work+0x29/0xa1 [nbd]
 process_one_work+0x1f5/0x3f0
 worker_thread+0x2d/0x3d0
 ? rescuer_thread+0x340/0x340
 kthread+0x111/0x130
 ? kthread_create_on_node+0x60/0x60
 ret_from_fork+0x1f/0x30
---[ end trace b079c3c67f98bb7c ]---

This was preceded by us timing out everything and shutting down the
sockets for the device.  The problem is we had a request in the queue at
the same time, so we completed the request twice.  This can actually
happen in a lot of cases, we fail to get a ref on our config, we only
have one connection and just error out the command, etc.

Fix this by checking cmd->status in nbd_read_stat.  We only change this
under the cmd->lock, so we are safe to check this here and see if we've
already error'ed this command out, which would indicate that we've
completed it as well.

Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-25 14:20:03 -06:00
Josef Bacik
de6346ecbc nbd: protect cmd->status with cmd->lock
We already do this for the most part, except in timeout and clear_req.
For the timeout case we take the lock after we grab a ref on the config,
but that isn't really necessary because we're safe to touch the cmd at
this point, so just move the order around.

For the clear_req cause this is initiated by the user, so again is safe.

Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-25 14:20:01 -06:00
Xiubo Li
862488105b nbd: fix possible sysfs duplicate warning
1. nbd_put takes the mutex and drops nbd->ref to 0. It then does
idr_remove and drops the mutex.

2. nbd_genl_connect takes the mutex. idr_find/idr_for_each fails
to find an existing device, so it does nbd_dev_add.

3. just before the nbd_put could call nbd_dev_remove or not finished
totally, but if nbd_dev_add try to add_disk, we can hit:

debugfs: Directory 'nbd1' with parent 'block' already present!

This patch will make sure all the disk add/remove stuff are done
by holding the nbd_index_mutex lock.

Reported-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-10 09:44:56 -06:00
Xiubo Li
8454d68563 nbd: fix possible page fault for nbd disk
When the NBD_CFLAG_DESTROY_ON_DISCONNECT flag is set and at the same
time when the socket is closed due to the server daemon is restarted,
just before the last DISCONNET is totally done if we start a new connection
by using the old nbd_index, there will be crashing randomly, like:

<3>[  110.151949] block nbd1: Receive control failed (result -32)
<1>[  110.152024] BUG: unable to handle page fault for address: 0000058000000840
<1>[  110.152063] #PF: supervisor read access in kernel mode
<1>[  110.152083] #PF: error_code(0x0000) - not-present page
<6>[  110.152094] PGD 0 P4D 0
<4>[  110.152106] Oops: 0000 [#1] SMP PTI
<4>[  110.152120] CPU: 0 PID: 6698 Comm: kworker/u5:1 Kdump: loaded Not tainted 5.3.0-rc4+ #2
<4>[  110.152136] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
<4>[  110.152166] Workqueue: knbd-recv recv_work [nbd]
<4>[  110.152187] RIP: 0010:__dev_printk+0xd/0x67
<4>[  110.152206] Code: 10 e8 c5 fd ff ff 48 8b 4c 24 18 65 48 33 0c 25 28 00 [...]
<4>[  110.152244] RSP: 0018:ffffa41581f13d18 EFLAGS: 00010206
<4>[  110.152256] RAX: ffffa41581f13d30 RBX: ffff96dd7374e900 RCX: 0000000000000000
<4>[  110.152271] RDX: ffffa41581f13d20 RSI: 00000580000007f0 RDI: ffffffff970ec24f
<4>[  110.152285] RBP: ffffa41581f13d80 R08: ffff96dd7fc17908 R09: 0000000000002e56
<4>[  110.152299] R10: ffffffff970ec24f R11: 0000000000000003 R12: ffff96dd7374e900
<4>[  110.152313] R13: 0000000000000000 R14: ffff96dd7374e9d8 R15: ffff96dd6e3b02c8
<4>[  110.152329] FS:  0000000000000000(0000) GS:ffff96dd7fc00000(0000) knlGS:0000000000000000
<4>[  110.152362] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[  110.152383] CR2: 0000058000000840 CR3: 0000000067cc6002 CR4: 00000000001606f0
<4>[  110.152401] Call Trace:
<4>[  110.152422]  _dev_err+0x6c/0x83
<4>[  110.152435]  nbd_read_stat.cold+0xda/0x578 [nbd]
<4>[  110.152448]  ? __switch_to_asm+0x34/0x70
<4>[  110.152468]  ? __switch_to_asm+0x40/0x70
<4>[  110.152478]  ? __switch_to_asm+0x34/0x70
<4>[  110.152491]  ? __switch_to_asm+0x40/0x70
<4>[  110.152501]  ? __switch_to_asm+0x34/0x70
<4>[  110.152511]  ? __switch_to_asm+0x40/0x70
<4>[  110.152522]  ? __switch_to_asm+0x34/0x70
<4>[  110.152533]  recv_work+0x35/0x9e [nbd]
<4>[  110.152547]  process_one_work+0x19d/0x340
<4>[  110.152558]  worker_thread+0x50/0x3b0
<4>[  110.152568]  kthread+0xfb/0x130
<4>[  110.152577]  ? process_one_work+0x340/0x340
<4>[  110.152609]  ? kthread_park+0x80/0x80
<4>[  110.152637]  ret_from_fork+0x35/0x40

This is very easy to reproduce by running the nbd-runner.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-17 20:03:49 -06:00
Xiubo Li
ec76a7b922 nbd: rename the runtime flags as NBD_RT_ prefixed
Preparing for the destory when disconnecting crash fixing.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-17 20:03:49 -06:00
Mike Christie
e9e006f5fc nbd: fix max number of supported devs
This fixes a bug added in 4.10 with commit:

commit 9561a7ade0c205bc2ee035a2ac880478dcc1a024
Author: Josef Bacik <jbacik@fb.com>
Date:   Tue Nov 22 14:04:40 2016 -0500

    nbd: add multi-connection support

that limited the number of devices to 256. Before the patch we could
create 1000s of devices, but the patch switched us from using our
own thread to using a work queue which has a default limit of 256
active works.

The problem is that our recv_work function sits in a loop until
disconnection but only handles IO for one connection. The work is
started when the connection is started/restarted, but if we end up
creating 257 or more connections, the queue_work call just queues
connection257+'s recv_work and that waits for connection 1 - 256's
recv_work to be disconnected and that work instance completing.

Instead of reverting back to kthreads, this has us allocate a
workqueue_struct per device, so we can block in the work.

Cc: stable@vger.kernel.org
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-20 12:44:07 -06:00
Mike Christie
2da22da573 nbd: fix zero cmd timeout handling v2
This fixes a regression added in 4.9 with commit:

commit 0eadf37afc2500e1162c9040ec26a705b9af8d47
Author: Josef Bacik <jbacik@fb.com>
Date:   Thu Sep 8 12:33:40 2016 -0700

    nbd: allow block mq to deal with timeouts

where before the patch userspace would set the timeout to 0 to disable
it. With the above patch, a zero timeout tells the block layer to use
the default value of 30 seconds. For setups where commands can take a
long time or experience transient issues like network disruptions this
then results in IO errors being sent to the application.

To fix this, the patch still uses the common block layer timeout
framework, but if zero is set, nbd just logs a message and then resets
the timer when it expires.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-20 12:44:05 -06:00
Mike Christie
887e975c41 nbd: add missing config put
Fix bug added with the patch:

commit 8f3ea35929a0806ad1397db99a89ffee0140822a
Author: Josef Bacik <josef@toxicpanda.com>
Date:   Mon Jul 16 12:11:35 2018 -0400

    nbd: handle unexpected replies better

where if the timeout handler runs when the completion path is and we fail
to grab the mutex in the timeout handler we will leave a config reference
and cannot free the config later.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-20 12:44:04 -06:00
Mike Christie
00514677ed nbd: add function to convert blk req op to nbd cmd
This adds a helper function to convert a block req op to a nbd cmd type.
It will be used in the last patch to log the type in the timeout
handler.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-20 12:44:02 -06:00
Mike Christie
55313e92bd nbd: add set cmd timeout helper
Add a helper to set the cmd timeout. It does not really do a lot now,
but will be more useful in the next patches.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-20 12:44:01 -06:00
Munehisa Kamata
2b5c8f0063 nbd: replace kill_bdev() with __invalidate_device() again
Commit abbbdf12497d ("replace kill_bdev() with __invalidate_device()")
once did this, but 29eaadc03649 ("nbd: stop using the bdev everywhere")
resurrected kill_bdev() and it has been there since then. So buffer_head
mappings still get killed on a server disconnection, and we can still
hit the BUG_ON on a filesystem on the top of the nbd device.

  EXT4-fs (nbd0): mounted filesystem with ordered data mode. Opts: (null)
  block nbd0: Receive control failed (result -32)
  block nbd0: shutting down sockets
  print_req_error: I/O error, dev nbd0, sector 66264 flags 3000
  EXT4-fs warning (device nbd0): htree_dirblock_to_tree:979: inode #2: lblock 0: comm ls: error -5 reading directory block
  print_req_error: I/O error, dev nbd0, sector 2264 flags 3000
  EXT4-fs error (device nbd0): __ext4_get_inode_loc:4690: inode #2: block 283: comm ls: unable to read itable block
  EXT4-fs error (device nbd0) in ext4_reserve_inode_write:5894: IO failure
  ------------[ cut here ]------------
  kernel BUG at fs/buffer.c:3057!
  invalid opcode: 0000 [#1] SMP PTI
  CPU: 7 PID: 40045 Comm: jbd2/nbd0-8 Not tainted 5.1.0-rc3+ #4
  Hardware name: Amazon EC2 m5.12xlarge/, BIOS 1.0 10/16/2017
  RIP: 0010:submit_bh_wbc+0x18b/0x190
  ...
  Call Trace:
   jbd2_write_superblock+0xf1/0x230 [jbd2]
   ? account_entity_enqueue+0xc5/0xf0
   jbd2_journal_update_sb_log_tail+0x94/0xe0 [jbd2]
   jbd2_journal_commit_transaction+0x12f/0x1d20 [jbd2]
   ? __switch_to_asm+0x40/0x70
   ...
   ? lock_timer_base+0x67/0x80
   kjournald2+0x121/0x360 [jbd2]
   ? remove_wait_queue+0x60/0x60
   kthread+0xf8/0x130
   ? commit_timeout+0x10/0x10 [jbd2]
   ? kthread_bind+0x10/0x10
   ret_from_fork+0x35/0x40

With __invalidate_device(), I no longer hit the BUG_ON with sync or
unmount on the disconnected device.

Fixes: 29eaadc03649 ("nbd: stop using the bdev everywhere")
Cc: linux-block@vger.kernel.org
Cc: Ratna Manoj Bolla <manoj.br@gmail.com>
Cc: nbd@other.debian.org
Cc: stable@vger.kernel.org
Cc: David Woodhouse <dwmw@amazon.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Munehisa Kamata <kamatam@amazon.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-31 08:51:56 -06:00
Mike Christie
4ddeaae890 nbd: add netlink reconfigure resize support
If the device is setup with ioctl we can resize the device after the
initial setup, but if the device is setup with netlink we cannot use the
resize related ioctls and there is no netlink reconfigure size ATTR
handling code.

This patch adds netlink reconfigure resize support to match the ioctl
interface.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-10 21:21:31 -06:00
Xiubo Li
553768d116 nbd: fix crash when the blksize is zero
This will allow the blksize to be set zero and then use 1024 as
default.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
[fix to use goto out instead of return in genl_connect]
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-10 21:21:16 -06:00
Thomas Gleixner
eb1fe3bfe8 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 127
Based on 1 normalized pattern(s):

  this file is released under gplv2 or later

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527063114.295960793@linutronix.de
Link: https://lkml.kernel.org/r/20190524100843.018830140@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:25:13 -07:00
David S. Miller
5f0d736e7f Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2019-04-28

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Introduce BPF socket local storage map so that BPF programs can store
   private data they associate with a socket (instead of e.g. separate hash
   table), from Martin.

2) Add support for bpftool to dump BTF types. This is done through a new
   `bpftool btf dump` sub-command, from Andrii.

3) Enable BPF-based flow dissector for skb-less eth_get_headlen() calls which
   was currently not supported since skb was used to lookup netns, from Stanislav.

4) Add an opt-in interface for tracepoints to expose a writable context
   for attached BPF programs, used here for NBD sockets, from Matt.

5) BPF xadd related arm64 JIT fixes and scalability improvements, from Daniel.

6) Change the skb->protocol for bpf_skb_adjust_room() helper in order to
   support tunnels such as sit. Add selftests as well, from Willem.

7) Various smaller misc fixes.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-28 08:42:41 -04:00
Johannes Berg
ef6243acb4 genetlink: optionally validate strictly/dumps
Add options to strictly validate messages and dump messages,
sometimes perhaps validating dump messages non-strictly may
be required, so add an option for that as well.

Since none of this can really be applied to existing commands,
set the options everwhere using the following spatch:

    @@
    identifier ops;
    expression X;
    @@
    struct genl_ops ops[] = {
    ...,
     {
            .cmd = X,
    +       .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
            ...
     },
    ...
    };

For new commands one should just not copy the .validate 'opt-out'
flags and thus get strict validation.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27 17:07:22 -04:00
Johannes Berg
8cb081746c netlink: make validation more configurable for future strictness
We currently have two levels of strict validation:

 1) liberal (default)
     - undefined (type >= max) & NLA_UNSPEC attributes accepted
     - attribute length >= expected accepted
     - garbage at end of message accepted
 2) strict (opt-in)
     - NLA_UNSPEC attributes accepted
     - attribute length >= expected accepted

Split out parsing strictness into four different options:
 * TRAILING     - check that there's no trailing data after parsing
                  attributes (in message or nested)
 * MAXTYPE      - reject attrs > max known type
 * UNSPEC       - reject attributes with NLA_UNSPEC policy entries
 * STRICT_ATTRS - strictly validate attribute size

The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().

Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.

We end up with the following renames:
 * nla_parse           -> nla_parse_deprecated
 * nla_parse_strict    -> nla_parse_deprecated_strict
 * nlmsg_parse         -> nlmsg_parse_deprecated
 * nlmsg_parse_strict  -> nlmsg_parse_deprecated_strict
 * nla_parse_nested    -> nla_parse_nested_deprecated
 * nla_validate_nested -> nla_validate_nested_deprecated

Using spatch, of course:
    @@
    expression TB, MAX, HEAD, LEN, POL, EXT;
    @@
    -nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
    +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression TB, MAX, NLA, POL, EXT;
    @@
    -nla_parse_nested(TB, MAX, NLA, POL, EXT)
    +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)

    @@
    expression START, MAX, POL, EXT;
    @@
    -nla_validate_nested(START, MAX, POL, EXT)
    +nla_validate_nested_deprecated(START, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, MAX, POL, EXT;
    @@
    -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
    +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)

For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.

Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.

Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.

In effect then, this adds fully strict validation for any new command.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27 17:07:21 -04:00
Michal Kubecek
ae0be8de9a netlink: make nla_nest_start() add NLA_F_NESTED flag
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.

Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().

Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:

@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)

@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27 17:03:44 -04:00
Andrew Hall
2abd2de712 nbd: add tracepoints for send/receive timing
This adds four tracepoints to nbd, enabling separate tracing of payload
and header sending/receipt.

In the send path for headers that have already been sent, we also
explicitly initialize the handle so it can be referenced by the later
tracepoint.

Signed-off-by: Andrew Hall <hall@fb.com>
Signed-off-by: Matt Mullins <mmullins@fb.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-26 19:04:19 -07:00
Matt Mullins
ea106722c7 nbd: trace sending nbd requests
This adds a tracepoint that can both observe the nbd request being sent
to the server, as well as modify that request , e.g., setting a flag in
the request that will cause the server to collect detailed tracing data.

The struct request * being handled is included to permit correlation
with the block tracepoints.

Signed-off-by: Matt Mullins <mmullins@fb.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-26 19:04:19 -07:00
Johannes Berg
3b0f31f2b8 genetlink: make policy common to family
Since maxattr is common, the policy can't really differ sanely,
so make it common as well.

The only user that did in fact manage to make a non-common policy
is taskstats, which has to be really careful about it (since it's
still using a common maxattr!). This is no longer supported, but
we can fake it using pre_doit.

This reduces the size of e.g. nl80211.o (which has lots of commands):

   text	   data	    bss	    dec	    hex	filename
 398745	  14323	   2240	 415308	  6564c	net/wireless/nl80211.o (before)
 397913	  14331	   2240	 414484	  65314	net/wireless/nl80211.o (after)
--------------------------------
   -832      +8       0    -824

Which is obviously just 8 bytes for each command, and an added 8
bytes for the new policy pointer. I'm not sure why the ops list is
counted as .text though.

Most of the code transformations were done using the following spatch:
    @ops@
    identifier OPS;
    expression POLICY;
    @@
    struct genl_ops OPS[] = {
    ...,
     {
    -	.policy = POLICY,
     },
    ...
    };

    @@
    identifier ops.OPS;
    expression ops.POLICY;
    identifier fam;
    expression M;
    @@
    struct genl_family fam = {
            .ops = OPS,
            .maxattr = M,
    +       .policy = POLICY,
            ...
    };

This also gets rid of devlink_nl_cmd_region_read_dumpit() accessing
the cb->data as ops, which we want to change in a later genl patch.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-22 10:38:23 -04:00
Li RongQing
cd46eb89df nbd: propagate genlmsg_reply return code
genlmsg_reply can fail, so propagate its return code

Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-28 14:06:37 -07:00
Ming Lei
56d18f62f5 block: kill BLK_MQ_F_SG_MERGE
QUEUE_FLAG_NO_SG_MERGE has been killed, so kill BLK_MQ_F_SG_MERGE too.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15 08:40:12 -07:00
Jan Kara
c8a83a6b54 nbd: Use set_blocksize() to set device blocksize
NBD can update block device block size implicitely through
bd_set_size(). Make it explicitely set blocksize with set_blocksize() as
this behavior of bd_set_size() is going away.

CC: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-01-15 07:30:54 -07:00
Jens Axboe
7baa85727d blk-mq-tag: change busy_iter_fn to return whether to continue or not
We have this functionality in sbitmap, but we don't export it in
blk-mq for users of the tags busy iteration. This can be useful
for stopping the iteration, if the caller doesn't need to find
more requests.

Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-08 10:24:07 -07:00
David Howells
aa563d7bca iov_iter: Separate type from direction and use accessor functions
In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.

Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements.  This makes it easier to add further
iterator types.  Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.

Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself.  Only the direction is required.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:07 +01:00
Jens Axboe
bc811f05d7 nbd: don't allow invalid blocksize settings
syzbot reports a divide-by-zero off the NBD_SET_BLKSIZE ioctl.
We need proper validation of the input here. Not just if it's
zero, but also if the value is a power-of-2 and in a valid
range. Add that.

Cc: stable@vger.kernel.org
Reported-by: syzbot <syzbot+25dbecbec1e62c6b0dd4@syzkaller.appspotmail.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-04 11:54:58 -06:00
David S. Miller
89b1698c93 Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net
The BTF conflicts were simple overlapping changes.

The virtio_net conflict was an overlap of a fix of statistics counter,
happening alongisde a move over to a bonafide statistics structure
rather than counting value on the stack.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-02 10:55:32 -07:00