78c276f549
syzbot reported a warning which could cause shift-out-of-bounds issue.
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x183/0x22e lib/dump_stack.c:120
ubsan_epilogue lib/ubsan.c:148 [inline]
__ubsan_handle_shift_out_of_bounds+0x432/0x4d0 lib/ubsan.c:395
exfat_read_boot_sector fs/exfat/super.c:471 [inline]
__exfat_fill_super fs/exfat/super.c:556 [inline]
exfat_fill_super+0x2acb/0x2d00 fs/exfat/super.c:624
get_tree_bdev+0x406/0x630 fs/super.c:1291
vfs_get_tree+0x86/0x270 fs/super.c:1496
do_new_mount fs/namespace.c:2881 [inline]
path_mount+0x1937/0x2c50 fs/namespace.c:3211
do_mount fs/namespace.c:3224 [inline]
__do_sys_mount fs/namespace.c:3432 [inline]
__se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3409
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
exfat specification describe sect_per_clus_bits field of boot sector
could be at most 25 - sect_size_bits and at least 0. And sect_size_bits
can also affect this calculation, It also needs validation.
This patch add validation for sect_per_clus_bits and sect_size_bits
field of boot sector.
Fixes: 719c1e182916 ("exfat: add super block operations")
Cc: stable@vger.kernel.org # v5.9+
Reported-by: syzbot+da4fe66aaadd3c2e2d1c@syzkaller.appspotmail.com
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.