Answer in brief
CVE-2026-98103 records a Unknown severity vulnerability in igmp: convert struct ip_sf_list to RCU. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=23d2b94043ca8835bd1e67749020e839f396a1c2 <f5182dfad54277267a8cb0c004a9cd4cf35aeebb || >=23d2b94043ca8835bd1e67749020e839f396a1c2 <d3011d1f293478c730aa0870490afa145c37600e || >=23d2b94043ca8835bd1e67749020e839f396a1c2 <e3206419bdb04e2087d8cc6be324df8639b3fac5 || >=23d2b94043ca8835bd1e67749020e839f396a1c2 <2987ee196c88dbde0463dc87d5fb209c684e34a2 || b24065948ae6c48c9e20891f8cfe9850f1d748be || e9924c4204ede999b0515fd31a370a1e27f676bc || 78967749984cf3614de346c90f3e259ff8272735 || 4768973dffed4d0126854514335ed4fe87bec1ab || d84708451d9041dff8a81e3718f821f12d2eb6c5 || ddd7e8b7b84836c584a284b98ca9bd7a348a0558 || 961447ff60291b91e27d5c32fa549c1411ad3b70 || d1a3c6d5925a8d00a32c5ef2d674dd9c0ce89c95 || >=4.4.284 <4.5 || >=4.9.283 <4.10 || >=4.14.247 <4.15 || >=4.19.207 <4.20 || >=5.4.145 <5.5 || >=5.10.64 <5.11 || >=5.13.16 <5.14 || >=5.14.3 <5.15 | f5182dfad54277267a8cb0c004a9cd4cf35aeebb, d3011d1f293478c730aa0870490afa145c37600e, e3206419bdb04e2087d8cc6be324df8639b3fac5, 2987ee196c88dbde0463dc87d5fb209c684e34a2, 4.5, 4.10, 4.15, 4.20, 5.5, 5.11, 5.14, 5.15 |
| Linux/Linuxgeneric | 5.15 | Not reported |
Published upstream
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 25, 2026
In the Linux kernel, the following vulnerability has been resolved: igmp: convert struct ip_sf_list to RCU Commit 23d2b94043ca ("igmp: Add ip_mc_list lock in ip_check_mc_rcu") added spin_lock_bh(&im->lock) to ip_check_mc_rcu() to prevent a use-after-free while iterating im->sources during concurrent deletions. However, ip_check_mc_rcu() is called from RCU read-side critical sections in packet receive and route lookup fast paths (e.g. __mkroute_output(), ip_route_input_rcu(), and __udp4_lib_rcv()). When igmpv3_send_cr() or igmpv3_send_report() holds &pmc->lock and calls add_grec() -> igmpv3_newpack() -> ip_route_output_ports(), an XFRM policy matching a multicast destination triggers xfrm_tmpl_resolve_one() -> xfrm4_get_saddr() -> __mkroute_output() -> ip_check_mc_rcu(). This attempts to acquire &im->lock while &pmc->lock is already held on the same CPU, triggering a lockdep recursive locking warning / deadlock. Fix this by converting IPv4 struct ip_sf_list to RCU, mirroring the IPv6 implementation in net/ipv6/mcast.c: 1. Add struct rcu_head to struct ip_sf_list and annotate sf_next, sources, and tomb as __rcu pointers. 2. Use rcu_assign_pointer() and kfree_rcu() for list updates and deletions. 3. Remove spin_lock_bh(&im->lock) from ip_check_mc_rcu() and traverse im->sources locklessly with for_each_psf_rcu(), reading and writing counter fields with READ_ONCE() and WRITE_ONCE(). Note: RCU conversion of /proc/net/mcfilter will be done in a separate patch.
Quoted source text, attributed separately from HOL analysis.