CVE-2026-63990

In the Linux kernel, the following vulnerability has been resolved: bonding: refuse to enslave CAN devices syzbot reported a kernel paging request crash in can_rx_unregister() inside net/can/af_can.c. The crash occurs because a virtual CAN device (vxcan) is being enslaved to a bonding master. During the enslavement process, the bonding driver mutates and modifies the network device states to fit an Ethernet-like aggregation model. However, CAN devices operate on a completely different Layer 2 architecture, relying on the CAN mid-layer private data structure (can_ml_priv) instead of standard Ethernet structures. Since bonding does not initialize or maintain these CAN structures, subsequent operations on the half-enslaved interface (such as closing associated sockets via isotp_release) lead to a null-pointer dereference when accessing the CAN receiver lists. Bonding CAN interfaces is architecturally invalid as CAN lacks MAC addresses, ARP capabilities, and standard Ethernet link-layer mechanisms. While generic loopback devices are blocked globally in net/core/dev.c, virtual CAN devices bypass this check because they do not carry the IFF_LOOPBACK flag, despite acting as local software-loopbacks. Fix this by explicitly blocking network devices of type ARPHRD_CAN from being enslaved at the very beginning of bond_enslave(). This prevents illegal state mutations, eliminates the resulting KASAN crashes, and avoids potential memory leaks from incomplete socket cleanups. As the CAN support has been added a long time after bonding the Fixes-tag points to the introduction of ARPHRD_CAN that would have needed a specific handling in bonding_main.c.

• CWE-476

• https://git.kernel.org/stable/c/02f1c87ded33b43d48b4a1d665da15f2157b30d8Patch
• https://git.kernel.org/stable/c/41e8478c4cd896d3abbe33d41afc90c84ac66602Patch
• https://git.kernel.org/stable/c/563090e5d450c665f70d955a39f9587afc7842ebPatch
• https://git.kernel.org/stable/c/69b78b5f3033272e53a2dc2dad675962654a5b38Patch
• https://git.kernel.org/stable/c/8ba68464e4787b6a7ec938826e16124df20fd23dPatch
• https://git.kernel.org/stable/c/9ea8a648d9120f7652bcde1ce2c4ad66871af707Patch
• https://git.kernel.org/stable/c/f4d78a81f57df82e9d82a2c07471fed1a1235893Patch

Published

Jul 19, 2026

Last Modified

Oct 8, 2026

Status

Analyzed

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-63985In the Linux kernel, the following vulnerability has been re…7.8
• CVE-2026-63986In the Linux kernel, the following vulnerability has been re…5.5
• CVE-2026-63987In the Linux kernel, the following vulnerability has been re…7.8
• CVE-2026-63988In the Linux kernel, the following vulnerability has been re…5.5
• CVE-2026-63989In the Linux kernel, the following vulnerability has been re…5.5
• CVE-2026-6399The General Options plugin for WordPress is vulnerable to St…4.4
• CVE-2026-63991In the Linux kernel, the following vulnerability has been re…5.5
• CVE-2026-63992In the Linux kernel, the following vulnerability has been re…9.1
• CVE-2026-63993In the Linux kernel, the following vulnerability has been re…9.8
• CVE-2026-63994In the Linux kernel, the following vulnerability has been re…9.8
• CVE-2026-63995In the Linux kernel, the following vulnerability has been re…7.8
• CVE-2026-63996In the Linux kernel, the following vulnerability has been re…7.8