CVE-2026-23001

In the Linux kernel, the following vulnerability has been resolved:

macvlan: fix possible UAF in macvlan_forward_source()

Add RCU protection on (struct macvlan_source_entry)->vlan.

Whenever macvlan_hash_del_source() is called, we must clear entry->vlan pointer before RCU grace period starts.

This allows macvlan_forward_source() to skip over entries queued for freeing.

Note that macvlan_dev are already RCU protected, as they are embedded in a standard netdev (netdev_priv(ndev)).

https: //lore.kernel.org/netdev/695fb1e8.050a0220.1c677c.039f.GAE@google.com/T/#u

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/15f6faf36e162532bec5cc05eb3fc622108bf2ed
• https://git.kernel.org/stable/c/232afc74a6dde0fe1830988e5827921f5ec9bb3f
• https://git.kernel.org/stable/c/484919832e2db6ce1e8add92c469e5d459a516b5
• https://git.kernel.org/stable/c/6dbead9c7677186f22b7981dd085a0feec1f038e
• https://git.kernel.org/stable/c/7470a7a63dc162f07c26dbf960e41ee1e248d80e
• https://git.kernel.org/stable/c/8133e85b8a3ec9f10d861e0002ec6037256e987e
• https://git.kernel.org/stable/c/8518712a2ca952d6da2238c6f0a16b4ae5ea3f13