Description

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.

Classification

CVE ID: CVE-2025-21759

Affected Products

Vendor: Linux, Linux

Product: Linux, Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.02% (probability of being exploited)

EPSS Percentile: 1.82% (scored less or equal to compared to others)

EPSS Date: 2025-03-27 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-21759
https://git.kernel.org/stable/c/81b25a07ebf53f9ef4ca8f3d96a8ddb94561dd5a
https://git.kernel.org/stable/c/0bf8e2f3768629d437a32cb824149e6e98254381
https://git.kernel.org/stable/c/8e92d6a413feaf968a33f0b439ecf27404407458
https://git.kernel.org/stable/c/087c1faa594fa07a66933d750c0b2610aa1a2946

Timeline