CVE-2022-49380

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

f2fs: fix to avoid f2fs_bug_on() in dec_valid_node_count()

As Yanming reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=215897

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

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

The kernel message is shown below:

kernel BUG at fs/f2fs/f2fs.h:2511! Call Trace: f2fs_remove_inode_page+0x2a2/0x830 f2fs_evict_inode+0x9b7/0x1510 evict+0x282/0x4e0 do_unlinkat+0x33a/0x540 __x64_sys_unlinkat+0x8e/0xd0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae

The root cause is: .total_valid_block_count or .total_valid_node_count could fuzzed to zero, then once dec_valid_node_count() was called, it will cause BUG_ON(), this patch fixes to print warning info and set SBI_NEED_FSCK into CP instead of panic.

Affected Software

References

• https://git.kernel.org/stable/c/2766ddaf45b69252bb8fe526b5b6e56904a9ae7a
• https://git.kernel.org/stable/c/4d17e6fe9293d57081ffdc11e1cf313e25e8fd9e
• https://git.kernel.org/stable/c/89d9a48d0cd30429463ea4e37ca83be6773ed5eb
• https://git.kernel.org/stable/c/bce859358d3d5940aa858e40ceee70ee6e76130e
• https://git.kernel.org/stable/c/ccffa99ae6a1f44797b57444c6a80382a42928fe
• https://git.kernel.org/stable/c/f8b3c3fcf33105bc1ee7788e3b51b0a1ae42ae53