CVE-2023-53763

In the Linux kernel, the following vulnerability has been resolved:

Revert "f2fs: fix to do sanity check on extent cache correctly"

syzbot reports a f2fs bug as below:

UBSAN: array-index-out-of-bounds in fs/f2fs/f2fs.h:3275:19

index 1409 is out of range for type '__le32[923]' (aka 'unsigned int[923]')

Call Trace:

__dump_stack lib/dump_stack.c:88 [inline]

dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106

ubsan_epilogue lib/ubsan.c:217 [inline]

__ubsan_handle_out_of_bounds+0x11c/0x150 lib/ubsan.c:348

inline_data_addr fs/f2fs/f2fs.h:3275 [inline]

__recover_inline_status fs/f2fs/inode.c:113 [inline]

do_read_inode fs/f2fs/inode.c:480 [inline]

f2fs_iget+0x4730/0x48b0 fs/f2fs/inode.c:604

f2fs_fill_super+0x640e/0x80c0 fs/f2fs/super.c:4601

mount_bdev+0x276/0x3b0 fs/super.c:1391

legacy_get_tree+0xef/0x190 fs/fs_context.c:611

vfs_get_tree+0x8c/0x270 fs/super.c:1519

do_new_mount+0x28f/0xae0 fs/namespace.c:3335

do_mount fs/namespace.c:3675 [inline]

__do_sys_mount fs/namespace.c:3884 [inline]

__se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3861

do_syscall_x64 arch/x86/entry/common.c:50 [inline]

do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80

entry_SYSCALL_64_after_hwframe+0x63/0xcd

The issue was bisected to:

commit d48a7b3a72f121655d95b5157c32c7d555e44c05

Author: Chao Yu <[email protected]>

Date: Mon Jan 9 03:49:20 2023 +0000

f2fs: fix to do sanity check on extent cache correctly

The root cause is we applied both v1 and v2 of the patch, v2 is the right

fix, so it needs to revert v1 in order to fix reported issue.

v1:

commit d48a7b3a72f1 ("f2fs: fix to do sanity check on extent cache correctly")

https://lore.kernel.org/lkml/[email protected]/

v2:

commit 269d11948100 ("f2fs: fix to do sanity check on extent cache correctly")

https://lore.kernel.org/lkml/[email protected]/