CVE-2026-89838: f2fs: limit recovery filename logging to stored length
In the Linux kernel, the following vulnerability has been resolved:
f2fs: limit recovery filename logging to stored length
F2FS stores recovery filenames as a length plus a fixed-size iname buffer. The buffer is not NUL-terminated, but recoverinode() and recoverdentry() print it with %s.
For a 255-byte filename, recovery logging can read past iname into the following raw inode fields.
Print the name with a precision bounded by inamelen and F2FSNAMELEN.
Affected Software
Event History
Frequently Asked Questions
What conditions are required for the out-of-bounds read to occur?
F2FS recovery must process an inode or directory entry whose recovery filename is 255 bytes long. The vulnerable logging paths are recover_inode() and recover_dentry(), which print the non-NUL-terminated name buffer with %s.
What data could be exposed by the vulnerable logging?
Logging may read beyond the fixed-size i_name buffer and include bytes from raw inode fields that follow it in memory. The provided data describes an information disclosure through recovery filename logging, not a write or code-execution condition.
How is the issue fixed?
The fix prints recovery filenames using a precision bounded by both i_namelen and F2FS_NAME_LEN, rather than treating the stored buffer as a NUL-terminated string. The referenced stable kernel commits contain the remediation.