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.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.