vulnerability
Red Hat: CVE-2025-21759: kernel: ipv6: mcast: extend RCU protection in igmp6_send() (Multiple Advisories)
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 6 | (AV:L/AC:L/Au:S/C:P/I:P/A:C) | Feb 27, 2025 | Jul 9, 2025 | Jan 28, 2026 |
Severity
6
CVSS
(AV:L/AC:L/Au:S/C:P/I:P/A:C)
Published
Feb 27, 2025
Added
Jul 9, 2025
Modified
Jan 28, 2026
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.
Solutions
no-fix-redhat-rpm-packageredhat-upgrade-kernelredhat-upgrade-kernel-rt
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