CVE-2026-31714: f2fs: fix to avoid memory leak in f2fs_rename()
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid memory leak in f2fsrename()
syzbot reported a f2fs bug as below:
BUG: memory leak unreferenced object 0xffff888127f70830 (size 16): comm "syz.0.23", pid 6144, jiffies 4294943712 hex dump (first 16 bytes): 3c af 57 72 5b e6 8f ad 6e 8e fd 33 42 39 03 ff <.Wr[...n..3B9.. backtrace (crc 925f8a80): kmemleakallocrecursive include/linux/kmemleak.h:44 [inline] slabpostallochook mm/slub.c:4520 [inline] slaballocnode mm/slub.c:4844 [inline] dokmallocnode mm/slub.c:5237 [inline] kmallocnoprof+0x3bd/0x560 mm/slub.c:5250 kmallocnoprof include/linux/slab.h:954 [inline] fscryptsetupfilename+0x15e/0x3b0 fs/crypto/fname.c:364 f2fssetupfilename+0x52/0xb0 fs/f2fs/dir.c:143 f2fsrename+0x159/0xca0 fs/f2fs/namei.c:961 f2fsrename2+0xd5/0xf20 fs/f2fs/namei.c:1308 vfsrename+0x7ff/0x1250 fs/namei.c:6026 filenamerenameat2+0x4f4/0x660 fs/namei.c:6144 dosysrenameat2 fs/namei.c:6173 [inline] sesysrenameat2 fs/namei.c:6168 [inline] x64sysrenameat2+0x59/0x80 fs/namei.c:6168 dosyscallx64 arch/x86/entry/syscall64.c:63 [inline] dosyscall64+0xe2/0xf80 arch/x86/entry/syscall64.c:94 entrySYSCALL64afterhwframe+0x77/0x7f
The root cause is in commit 40b2d55e0452 ("f2fs: fix to create selinux label during whiteout initialization"), we added a call to f2fssetupfilename() without a matching call to f2fsfreefilename(), fix it.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Operational
Apply the source-level fix: ensure a matching call to f2fs_free_filename() is added where f2fs_setup_filename() is called (specifically in f2fs_rename()) so that memory allocated by f2fs_setup_filename() is freed on all code paths. Backport or merge the upstream commit that implements this fix into your kernel tree and rebuild/redeploy kernels as appropriate.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-31714?
CVE-2026-31714 is classified as a memory leak vulnerability in the f2fs component of the Linux kernel.
What impacts does CVE-2026-31714 have on system performance?
CVE-2026-31714 can lead to increased memory usage over time, potentially resulting in degraded system performance.
How do I fix CVE-2026-31714?
To fix CVE-2026-31714, update to the latest version of the Linux kernel that includes the fixes for this vulnerability.
Who is affected by CVE-2026-31714?
CVE-2026-31714 affects systems running the f2fs file system in specific versions of the Linux kernel.
What is the nature of CVE-2026-31714?
CVE-2026-31714 specifically addresses a memory leak issue encountered during the renaming operation in the f2fs file system.