CVE-2026-74400

A flaw was found in the Linux kernel. The BPF (Berkeley Packet Filter) kfuncs bpf_set_dentry_xattr and bpf_remove_dentry_xattr do not properly check for a null inode when handling negative dentries. This oversight can lead to a null pointer dereference. Additionally, warnings in bpf_xattr_read_permission() and bpf_xattr_write_permission() could be triggered by similar conditions. On systems configured with panic_on_warn, this vulnerability could result in a Denial of Service (DoS).

This vulnerability is assessed as Moderate impact for Red Hat products because exploitation requires local access and elevated administrative privileges to load custom BPF programs. An authorized user with privileges such as CAP_BPF or CAP_SYS_ADMIN could pass a negative directory entry to extended attribute BPF kfuncs, causing a kernel crash or triggering panics on configurations with panic_on_warn enabled. Unprivileged users cannot independently trigger this flaw, restricting the blast radius to a localized denial of service by privileged operators.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.