In the Linux kernel, the following vulnerability has been resolved: ima: Check for ERR_PTR from dentry_path() in validate_hash_algo() dentry_path() returns ERR_PTR(-ENAMETOOLONG) when the path exceeds the buffer

Overview

In the Linux kernel, the following vulnerability has been resolved:

ima: Check for ERR_PTR from dentry_path() in validate_hash_algo()

dentry_path() returns ERR_PTR(-ENAMETOOLONG) when the path exceeds the buffer. validate_hash_algo() passes the result straight to integrity_audit_msg() without checking. ERR_PTR is not NULL, so integrity_audit_message() sees a valid pointer and calls strlen() on it, which faults:

BUG: unable to handle page fault for address: ffffffffffffffdc
RIP: 0010:strlen+0x30/0xa0
Call Trace:
 audit_log_untrustedstring+0x19/0x30
 integrity_audit_message+0x366/0x4f0
 ima_inode_setxattr+0x512/0x5f0

Check for IS_ERR() and use NULL instead, which makes the audit message skip the name= field instead of crashing.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.