CVE-2026-31411

Katalog CVE

CVSS 5.5 · Medium EPSS 0,17%

Kerentanan NULL Pointer Dereference pada linux kernel. Skor CVSS 3.1 5.5 (Medium) menurut NVD.

Deskripsi (NVD)

In the Linux kernel, the following vulnerability has been resolved: net: atm: fix crash due to unvalidated vcc pointer in sigd_send() Reproducer available at [1]. The ATM send path (sendmsg -> vcc_sendmsg -> sigd_send) reads the vcc pointer from msg->vcc and uses it directly without any validation. This pointer comes from userspace via sendmsg() and can be arbitrarily forged: int fd = socket(AF_ATMSVC, SOCK_DGRAM, 0); ioctl(fd, ATMSIGD_CTRL); // become ATM signaling daemon struct msghdr msg = { .msg_iov = &iov, ... }; *(unsigned long *)(buf + 4) = 0xdeadbeef; // fake vcc pointer sendmsg(fd, &msg, 0); // kernel dereferences 0xdeadbeef In normal operation, the kernel sends the vcc pointer to the signaling daemon via sigd_enq() when processing operations like connect(), bind(), or listen(). The daemon is expected to return the same pointer when responding. However, a malicious daemon can send arbitrary pointer values. Fix this by introducing find_get_vcc() which validates the pointer by searching through vcc_hash (similar to how sigd_close() iterates over all VCCs), and acquires a reference via sock_hold() if found. Since struct atm_vcc embeds struct sock as its first member, they share the same lifetime. Therefore using sock_hold/sock_put is sufficient to keep the vcc alive while it is being used. Note that there may be a race with sigd_close() which could mark the vcc with various flags (e.g., ATM_VF_RELEASED) after find_get_vcc() returns. However, sock_hold() guarantees the memory remains valid, so this race only affects the logical state, not memory safety. [1]: https://gist.github.com/mrpre/1ba5949c45529c511152e2f4c755b0f3

Rincian

Terbit di NVD

8 April 2026

Terakhir diubah

25 Juli 2026

Status NVD

Modified

CVSS 3.1

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

Jenis kelemahan (CWE)

CWE-476: NULL Pointer Dereference

EPSS (30 hari)

0,17% peluang dieksploitasi; lebih tinggi dari 5,9% CVE lain

Produk dan versi terdampak

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

• https://git.kernel.org/stable/c/1c8bda3df028d5e54134077dcd09f46ca8cfceb5 patch
• https://git.kernel.org/stable/c/21c303fec138c002f90ed33bce60e807d53072bb patch
• https://git.kernel.org/stable/c/3e1a8b00095246a9a2b46b57f6d471c6d3c00ed2 patch
• https://git.kernel.org/stable/c/440c9a5fc477a8ee259d8bf669531250b8398651 patch
• https://git.kernel.org/stable/c/69d3f9ee5489e6e8b66defcfa226e91d82393297 patch
• https://git.kernel.org/stable/c/ae88a5d2f29b69819dc7b04086734439d074a643 patch
• https://git.kernel.org/stable/c/c96549d07dfdd51aadf0722cfb40711574424840 patch
• https://git.kernel.org/stable/c/e3f80666c2739296c3b69a127300455c43aa1067 patch
• https://cert-portal.siemens.com/productcert/html/ssa-019113.html
• https://cert-portal.siemens.com/productcert/html/ssa-082556.html