Linux Kernel Binfmt Misc Shift-Out-Of-Bounds Vulnerability

A shift-out-of-bounds vulnerability has been identified in the Linux kernel's binfmt_misc component. This issue arises from a left shift operation of 1 by 31 places, which cannot be represented within the 'int' data type. The vulnerability was detected by Undefined Behavior Sanitizer (UBSAN), indicating a potential flaw in how special flags are handled in the binary format management system.

Impact

Exploitation of this vulnerability could lead to undefined behavior in the kernel, potentially allowing for arbitrary code execution or other malicious actions.

Reproduction

The vulnerability can be reproduced by writing to the binfmt_misc filesystem with a payload that triggers the shift-out-of-bounds condition. This can be done by creating a custom binary format entry that includes special flags designed to cause the left shift operation to exceed the limits of the 'int' data type.

Remediation

Users can upgrade to the patched version of the Linux kernel available in the Linux Kernel Stable PPA.