Medium (5.5) in linux linux kernel. EPSS 0.3% chance of exploitation in the next 30 days.
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to do sanity check on block address in f2fs_do_zero_range()
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.
Severity
CVSS 3.1
5.5 medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
0.3% chance of exploitation in the next 30 days; higher than 20% of CVEs (scores of 2026-10-31)