CVE-2022-49380: f2fs: fix to avoid f2fs_bug_on() in dec_valid_node_count()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-02-26 · updated 2026-08-15

Description

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 products

Linux kernel: from 3.8 before 5.4.198; from 5.5 before 5.10.121; from 5.11 before 5.15.46; from 5.16 before 5.17.14; from 5.18 before 5.18.3 — fixed in 5.10.121, 5.15.46, 5.17.14, 5.18.3, 5.4.198

How to fix

Upgrade to a fixed version: Linux kernel 5.10.121, 5.15.46, 5.17.14, 5.18.3. Check the vendor advisory for mitigations.

References

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