CVE-2022-50273

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

f2fs: fix to do sanity check on destination blkaddr during recovery

As Wenqing Liu reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=216456

loop5: detected capacity change from 0 to 131072

F2FS-fs (loop5): recover_inode: ino = 6, name = hln, inline = 1

F2FS-fs (loop5): recover_data: ino = 6 (i_size: recover) err = 0

F2FS-fs (loop5): recover_inode: ino = 6, name = hln, inline = 1

F2FS-fs (loop5): recover_data: ino = 6 (i_size: recover) err = 0

F2FS-fs (loop5): recover_inode: ino = 6, name = hln, inline = 1

F2FS-fs (loop5): recover_data: ino = 6 (i_size: recover) err = 0

F2FS-fs (loop5): Bitmap was wrongly set, blk:5634

------------[ cut here ]------------

WARNING: CPU: 3 PID: 1013 at fs/f2fs/segment.c:2198

RIP: 0010:update_sit_entry+0xa55/0x10b0 [f2fs]

Call Trace:

<TASK>

f2fs_do_replace_block+0xa98/0x1890 [f2fs]

f2fs_replace_block+0xeb/0x180 [f2fs]

recover_data+0x1a69/0x6ae0 [f2fs]

f2fs_recover_fsync_data+0x120d/0x1fc0 [f2fs]

f2fs_fill_super+0x4665/0x61e0 [f2fs]

mount_bdev+0x2cf/0x3b0

legacy_get_tree+0xed/0x1d0

vfs_get_tree+0x81/0x2b0

path_mount+0x47e/0x19d0

do_mount+0xce/0xf0

__x64_sys_mount+0x12c/0x1a0

do_syscall_64+0x38/0x90

entry_SYSCALL_64_after_hwframe+0x63/0xcd

If we enable CONFIG_F2FS_CHECK_FS config, it will trigger a kernel panic

instead of warning.

The root cause is: in fuzzed image, SIT table is inconsistent with inode

mapping table, result in triggering such warning during SIT table update.

This patch introduces a new flag DATA_GENERIC_ENHANCE_UPDATE, w/ this

flag, data block recovery flow can check destination blkaddr's validation

in SIT table, and skip f2fs_replace_block() to avoid inconsistent status.