In the Linux kernel, the following vulnerability has been resolved:
apparmor: fix NULL pointer dereference in __unix_needs_revalidation
When receiving file descriptors via SCM_RIGHTS, both the socket pointer and the socket's sk pointer can be NULL during socket setup or teardown, causing NULL pointer dereferences in __unix_needs_revalidation().
This is a regression in AppArmor 5.0.0 (kernel 6.17+) where the new __unix_needs_revalidation() function was added without proper NULL checks.
The crash manifests as: BUG: kernel NULL pointer dereference, address: 0x0000000000000018 RIP: aa_file_perm+0xb7/0x3b0 (or +0xbe/0x3b0, +0xc0/0x3e0) Call Trace: apparmor_file_receive+0x42/0x80 security_file_receive+0x2e/0x50 receive_fd+0x1d/0xf0 scm_detach_fds+0xad/0x1c0
The function dereferences sock->sk->sk_family without checking if either sock or sock->sk is NULL first.
Add NULL checks for both sock and sock->sk before accessing sk_family.
CVSS Details
- CVSS 3.1 Base Score: 5.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Ubuntu | — | Upgrade linux-image-gcp-64kUpgrade linux-image-aws-64k-6.17Upgrade linux-image-6.17.0-1026-nvidia-64kUpgrade linux-image-6.17.0-1018-gcp-64kUpgrade linux-image-gcp-64k-6.17Upgrade linux-image-nvidia-hwe-24.04Upgrade linux-image-nvidia-6.17Upgrade linux-image-nvidia-64k-hwe-24.04Upgrade linux-image-aws-64kUpgrade linux-image-6.17.0-1026-nvidiaUpgrade linux-image-gcp-6.17Upgrade linux-image-gcpUpgrade linux-image-awsUpgrade linux-image-6.17.0-1017-aws-64kUpgrade linux-image-6.17.0-1017-awsUpgrade linux-image-aws-6.17Upgrade linux-image-6.17.0-1018-gcpUpgrade linux-image-nvidia-64k-6.17 | May 31, 2026 | May 27, 2026 |
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