CVE-2026-31629
Description
In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: add missing return after LLCP_CLOSED checks In nfc_llcp_recv_hdlc() and nfc_llcp_recv_disc(), when the socket state is LLCP_CLOSED, the code correctly calls release_sock() and nfc_llcp_sock_put() but fails to return. Execution falls through to the remainder of the function, which calls release_sock() and nfc_llcp_sock_put() again. This results in a double release_sock() and a refcount underflow via double nfc_llcp_sock_put(), leading to a use-after-free. Add the missing return statements after the LLCP_CLOSED branches in both functions to prevent the fall-through.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-31629
Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2026-31629.html
Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/ff3d9e8f7244293e303f7b6ef70774291c7c27e9
Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/aba4712e8f0381cd5d196534ce2ad082626a5ab6
Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/8977fad2b3c6eefd414131168d597c5d1d5e1abf
Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/796e0cac058252d0ad34ebe288e6f7979b5fc9b2
Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/2b5dd4632966c39da6ba74dbc8689b309065e82c
Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/0eb1263a3b8c36418c9ba295c9ab3abed664edbf
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | affected | |
| debian | bullseye | affected | |
| debian | forky | fixed | 6.19.14-1 |
| debian | sid | fixed | 6.19.14-1 |
| debian | trixie | fixed | 6.12.85-1 |
| linux-kernel | affected | 6.6.136 |
References
- https://git.kernel.org/stable/c/0eb1263a3b8c36418c9ba295c9ab3abed664edbf
- https://git.kernel.org/stable/c/2b5dd4632966c39da6ba74dbc8689b309065e82c
- https://git.kernel.org/stable/c/796e0cac058252d0ad34ebe288e6f7979b5fc9b2
- https://git.kernel.org/stable/c/8977fad2b3c6eefd414131168d597c5d1d5e1abf
- https://git.kernel.org/stable/c/aba4712e8f0381cd5d196534ce2ad082626a5ab6
- https://git.kernel.org/stable/c/ff3d9e8f7244293e303f7b6ef70774291c7c27e9
- https://www.suse.com/security/cve/CVE-2026-31629.html
- https://security-tracker.debian.org/tracker/CVE-2026-31629
CWEs
CWE-667
Verify integrity in audit chain (admin only). AS-IS.