CVE-2024-47703: 
Linux Kernel vulnerability analysis and mitigation

A vulnerability in the Linux kernel's BPF LSM (Linux Security Module) subsystem was identified where a BPF program returning a positive number attached to file_alloc_security hook could cause a kernel panic. The issue was discovered in Linux kernel versions from 5.7 through 6.10.13 and 6.11 through 6.11.2. This occurs because the file system cannot filter out the positive number returned by the LSM program using IS_ERR, and misinterprets this positive number as a file pointer (NVD).

The vulnerability stems from the BPF LSM hook implementation where the file_alloc_security hook never returned a positive number before the BPF LSM introduction. The issue was addressed by adding LSM return value check in the verifier to ensure no unexpected values are returned. The vulnerability has been assigned a CVSS v3.1 Base Score of 5.5 (Medium) with vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (NVD).

When exploited, this vulnerability can cause a denial of service through a kernel panic. The impact is limited to local attacks and affects system availability, with no direct impact on confidentiality or integrity (NVD).

The vulnerability has been fixed in Linux kernel versions 6.10.13 and 6.11.2. The fix involves adding a check for BPF LSM return values in the verifier to prevent unexpected positive return values. Users should update their Linux kernel to these patched versions or later (Kernel Patch).