CVE-2024-26878: 
Linux Kernel vulnerability analysis and mitigation

CVE-2024-26878 is a vulnerability discovered in the Linux kernel's quota system. The issue involves a potential NULL pointer dereference that occurs due to a race condition between dquotfreeinode and quota_off operations (NVD). The vulnerability was first reported on April 17, 2024, and affects Linux kernel versions up to (excluding) 4.19.311, 5.4.273, 5.10.214, 5.15.153, and various other versions (Debian).

The vulnerability stems from a race condition in the kernel's quota system where if dquotfreeinode (or other routines) checks inode's quota pointers before quota_off sets it to NULL and then attempts to use it afterward, a NULL pointer dereference will be triggered. The issue has been assigned a CVSS v3.1 Base Score of 4.7 (Medium) with the vector string CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H (NVD).

The vulnerability can lead to a NULL pointer dereference in the Linux kernel, potentially resulting in a system crash or denial of service condition. The impact is limited by the requirement for local access and high attack complexity (NVD).

The issue has been fixed by using a temporary pointer to avoid the NULL pointer dereference. The fix has been implemented in various Linux kernel versions through patches. Multiple distributions have released updates to address this vulnerability, including Debian with versions 5.10.216-1~deb10u1 and 4.19.316-1 (Debian LTS).