CVE-2026-23319

Katalog CVE

CVSS 7.8 · High EPSS 0,13%

Kerentanan Use After Free pada linux kernel. Skor CVSS 3.1 7.8 (High) menurut NVD.

Deskripsi (NVD)

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix a UAF issue in bpf_trampoline_link_cgroup_shim The root cause of this bug is that when 'bpf_link_put' reduces the refcount of 'shim_link->link.link' to zero, the resource is considered released but may still be referenced via 'tr->progs_hlist' in 'cgroup_shim_find'. The actual cleanup of 'tr->progs_hlist' in 'bpf_shim_tramp_link_release' is deferred. During this window, another process can cause a use-after-free via 'bpf_trampoline_link_cgroup_shim'. Based on Martin KaFai Lau's suggestions, I have created a simple patch. To fix this: Add an atomic non-zero check in 'bpf_trampoline_link_cgroup_shim'. Only increment the refcount if it is not already zero. Testing: I verified the fix by adding a delay in 'bpf_shim_tramp_link_release' to make the bug easier to trigger: static void bpf_shim_tramp_link_release(struct bpf_link *link) { /* ... */ if (!shim_link->trampoline) return; + msleep(100); WARN_ON_ONCE(bpf_trampoline_unlink_prog(&shim_link->link, shim_link->trampoline, NULL)); bpf_trampoline_put(shim_link->trampoline); } Before the patch, running a PoC easily reproduced the crash(almost 100%) with a call trace similar to KaiyanM's report. After the patch, the bug no longer occurs even after millions of iterations.

Rincian

Terbit di NVD

25 Maret 2026

Terakhir diubah

14 Juli 2026

Status NVD

Modified

CVSS 3.1

7.8 (High), sumber NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H · uraikan di kalkulator

Jenis kelemahan (CWE)

CWE-416: Use After Free

EPSS (30 hari)

0,13% peluang dieksploitasi; lebih tinggi dari 2,0% CVE lain

Produk dan versi terdampak

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

• https://git.kernel.org/stable/c/3eeddb80191f7626ec1ef742bfff51ec3b0fa5c2 patch
• https://git.kernel.org/stable/c/4e8a0005d633a4adc98e3b65d5080f93b90d356b patch
• https://git.kernel.org/stable/c/529e685e522b9d7fb379dbe6929dcdf520e34c8c patch
• https://git.kernel.org/stable/c/56145d237385ca0e7ca9ff7b226aaf2eb8ef368b patch
• https://git.kernel.org/stable/c/9b02c5c4147f8af8ed783c8deb5df927a55c3951 patch
• https://git.kernel.org/stable/c/cfcfa0ca0212162aa472551266038e8fd6768cff patch
• https://cert-portal.siemens.com/productcert/html/ssa-019113.html
• https://cert-portal.siemens.com/productcert/html/ssa-082556.html