Linux Kernel BPF Exclusive Map Memory Leak Vulnerability

A memory leak vulnerability has been identified in the Linux kernel's BPF (Berkeley Packet Filter) subsystem. This issue arises when the 'excl_prog_hash' is 0, but 'excl_prog_hash_size' is non-zero. In such cases, the map created needs to be freed; otherwise, the memory allocated for the map will not be reclaimed, leading to a memory leak. This problem was reported by syzbot, which provided a backtrace indicating the source of the memory leak in the BPF syscall handling.

Impact

The vulnerability causes a memory leak in the BPF subsystem, where allocated memory is not properly reclaimed, potentially leading to increased memory usage and exhaustion over time.

Remediation

Users can apply the patch available in the Linux kernel stable tree to address this vulnerability. The patch can be downloaded as part of the Linux kernel source code.