CVE-2026-45966

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> apparmor: fix NULL pointer dereference in __unix_needs_revalidation<br /> <br /> When receiving file descriptors via SCM_RIGHTS, both the socket pointer<br /> and the socket&amp;#39;s sk pointer can be NULL during socket setup or teardown,<br /> causing NULL pointer dereferences in __unix_needs_revalidation().<br /> <br /> This is a regression in AppArmor 5.0.0 (kernel 6.17+) where the new<br /> __unix_needs_revalidation() function was added without proper NULL checks.<br /> <br /> The crash manifests as:<br /> BUG: kernel NULL pointer dereference, address: 0x0000000000000018<br /> RIP: aa_file_perm+0xb7/0x3b0 (or +0xbe/0x3b0, +0xc0/0x3e0)<br /> Call Trace:<br /> apparmor_file_receive+0x42/0x80<br /> security_file_receive+0x2e/0x50<br /> receive_fd+0x1d/0xf0<br /> scm_detach_fds+0xad/0x1c0<br /> <br /> The function dereferences sock-&gt;sk-&gt;sk_family without checking if either<br /> sock or sock-&gt;sk is NULL first.<br /> <br /> Add NULL checks for both sock and sock-&gt;sk before accessing sk_family.