Namjae Jeon 4e6e00704f exfat: fix shift-out-of-bounds in exfat_fill_super() ... commit 78c276f5495aa53a8beebb627e5bf6a54f0af34f upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-03-04 11:38:41 +01:00
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balloc.c
cache.c
dir.c
exfat_fs.h
exfat_raw.h
fatent.c
file.c
inode.c
Kconfig
Makefile
misc.c
namei.c
nls.c
super.c