CVE-2026-63990

CVE CVE-2026-63990EUVD EUVD-2026-45563Veröffentlicht 2026-07-19T14:56:11.000Z

Was das Advisory beschreibt

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.

Quelle: EUVD (ENISA), im Wortlaut der Meldung.

Produkte, die das Advisory nennt

Diese Angaben stammen aus der Meldung selbst, nicht aus einer Prüfung durch uns.

• Linux — Linux cd05acfe65ed2cf2db683fa9a6adb8d35635263b <563090e5d450c665f70d955a39f9587afc7842eb; patch: 6.12.93; patch: 6.1.176; cd05acfe65ed2cf2db683fa9a6adb8d35635263b <8ba68464e4787b6a7ec938826e16124df20fd23d; 2.6.25; patch: 7.1; cd05acfe65ed2cf2db683fa9a6adb8d35635263b <02f1c87ded33b43d48b4a1d665da15f2157b30d8; patch: 6.6.143; cd05acfe65ed2cf2db683fa9a6adb8d35635263b <41e8478c4cd896d3abbe33d41afc90c84ac66602; patch: 6.18.35; cd05acfe65ed2cf2db683fa9a6adb8d35635263b <f4d78a81f57df82e9d82a2c07471fed1a1235893; patch: 0; cd05acfe65ed2cf2db683fa9a6adb8d35635263b <9ea8a648d9120f7652bcde1ce2c4ad66871af707; patch: 5.15.210; cd05acfe65ed2cf2db683fa9a6adb8d35635263b <69b78b5f3033272e53a2dc2dad675962654a5b38; patch: 7.0.12

Die genannten Versionen sind die Angabe der Meldung. Patchlage vergleicht keine Versionsnummern und leitet aus ihnen keine Aussage ab — welche Version installiert ist, muss ein Mensch nachsehen.

Im Produktkatalog geführt

Für diese Produkte kann ein Bestand in Patchlage erfasst werden. Ein Advisory dazu erscheint am Morgen danach im Lagebericht.

• Linux — Linux

Patchlage meldet Treffer und Verdachtsfälle. Zu allem anderen sagt dieses System nichts — weder diese Seite noch der Lagebericht behauptet je, dass ein Bestand sicher ist.