f2fs: fix to do sanity check on block address in f2fs_do_zero_range()
authorChao Yu <chao@kernel.org>
Wed, 27 Apr 2022 09:51:40 +0000 (17:51 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 9 Jun 2022 08:23:17 +0000 (10:23 +0200)
commitf2e1c38b5ac64eb1a16a89c52fb419409d12c25b
treee66b38e124abdad19a9ba4c34924f74f52dadbe1
parentbce859358d3d5940aa858e40ceee70ee6e76130e
f2fs: fix to do sanity check on block address in f2fs_do_zero_range()

commit 25f8236213a91efdf708b9d77e9e51b6fc3e141c upstream.

As Yanming reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=215894

I have encountered a bug in F2FS file system in kernel v5.17.

I have uploaded the system call sequence as case.c, and a fuzzed image can
be found in google net disk

The kernel should enable CONFIG_KASAN=y and CONFIG_KASAN_INLINE=y. You can
reproduce the bug by running the following commands:

kernel BUG at fs/f2fs/segment.c:2291!
Call Trace:
 f2fs_invalidate_blocks+0x193/0x2d0
 f2fs_fallocate+0x2593/0x4a70
 vfs_fallocate+0x2a5/0xac0
 ksys_fallocate+0x35/0x70
 __x64_sys_fallocate+0x8e/0xf0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The root cause is, after image was fuzzed, block mapping info in inode
will be inconsistent with SIT table, so in f2fs_fallocate(), it will cause
panic when updating SIT with invalid blkaddr.

Let's fix the issue by adding sanity check on block address before updating
SIT table with it.

Cc: stable@vger.kernel.org
Reported-by: Ming Yan <yanming@tju.edu.cn>
Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/f2fs/file.c