CVE-2026-98103: igmp: convert struct ip_sf_list to RCU
igmp: convert struct ipsflist to RCU
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1 - Upgrade
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debian/linux-6.12to a version that resolves this vulnerability.Fixed in 6.12.113-1~deb12u1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1
Event History
Frequently Asked Questions
What conditions are involved in triggering the locking problem?
The described path requires IGMPv3 report processing to hold pmc->lock and an XFRM policy that matches a multicast destination. Route resolution can then enter ip_check_mc_rcu() from an RCU read-side critical section and attempt to acquire im->lock recursively on the same CPU.
How might an affected system present this issue?
The documented symptom is a lockdep recursive-locking warning or a deadlock. The underlying code was also intended to prevent a use-after-free while iterating multicast source entries during concurrent deletions.
Which systems are in scope based on the available information?
The issue concerns the Linux kernel's IPv4 IGMP multicast-source handling, particularly receive and route-lookup fast paths such as __mkroute_output(), ip_route_input_rcu(), and __udp4_lib_rcv(). The available data does not identify specific kernel versions or state whether a default configuration is affected.