Linux vulnerability

What happened

In the Linux kernel, the following vulnerability has been resolved: ipv6: mcast: extend RCU protection in igmp6_send() igmp6_send() can be called without RTNL or RCU being held. Extend RCU protection so that we can safely fetch the net pointer and avoid a potential UAF. Note that we no longer can use sock_alloc_send_skb() because ipv6.igmp_sk uses GFP_KERNEL allocations which can sleep. Instead use alloc_skb() and charge the net->ipv6.igmp_sk socket under RCU protection.

Affected versions

Linux: b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551 through before 638e8fe3563a82f298fe537a28d5342a97278cf1 (git); b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551 through before 6901bbb169e3add6c037218d996790cef6b3d650 (git); b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551 through before 7e0a818ecc4d62e7fb668ea02de0bfe8ba0b7dff (git); b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551 through before 81b25a07ebf53f9ef4ca8f3d96a8ddb94561dd5a (git); b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551 through before 0bf8e2f3768629d437a32cb824149e6e98254381 (git); b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551 through before 8e92d6a413feaf968a33f0b439ecf27404407458 (git); b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551 through before 087c1faa594fa07a66933d750c0b2610aa1a2946 (git); 2.6.26 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.