linux/fs/exfat
Namjae Jeon 78c276f549 exfat: fix shift-out-of-bounds in exfat_fill_super()
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: 719c1e1829 ("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>
2021-02-22 09:55:13 +09:00
..
balloc.c exfat: remove EXFAT_SB_DIRTY flag 2020-08-12 08:31:10 +09:00
cache.c exfat: fix use of uninitialized spinlock on error path 2020-10-07 14:27:13 +09:00
dir.c exfat: remove 'rwoffset' in exfat_inode_info 2020-10-22 08:29:11 +09:00
exfat_fs.h exfat: remove 'rwoffset' in exfat_inode_info 2020-10-22 08:29:11 +09:00
exfat_raw.h exfat: fix shift-out-of-bounds in exfat_fill_super() 2021-02-22 09:55:13 +09:00
fatent.c exfat: optimize exfat_zeroed_cluster() 2020-08-12 08:31:12 +09:00
file.c exfat: remove 'rwoffset' in exfat_inode_info 2020-10-22 08:29:11 +09:00
inode.c exfat: remove 'rwoffset' in exfat_inode_info 2020-10-22 08:29:11 +09:00
Kconfig exfat: Improve wording of EXFAT_DEFAULT_IOCHARSET config option 2020-06-09 16:48:39 +09:00
Makefile exfat: add Kconfig and Makefile 2020-03-05 21:00:40 -05:00
misc.c exfat: write multiple sectors at once 2020-08-12 08:31:11 +09:00
namei.c exfat: remove useless check in exfat_move_file() 2020-10-22 08:29:12 +09:00
nls.c exfat: Avoid allocating upcase table using kcalloc() 2020-12-22 12:31:17 +09:00
super.c exfat: fix shift-out-of-bounds in exfat_fill_super() 2021-02-22 09:55:13 +09:00