igmp: convert struct ip_sf_list to RCU
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.
CVE-2026-98103
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-98103
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "23d2b94043ca8835bd1e67749020e839f396a1c2",
"lessThan": "01131daffc4b64f1652e23dc3e6e2f601eda781d",
"versionType": "git"
},
{
"status": "affected",
"version": "23d2b94043ca8835bd1e67749020e839f396a1c2",
"lessThan": "f5182dfad54277267a8cb0c004a9cd4cf35aeebb",
"versionType": "git"
},
{
"status": "affected",
"version": "23d2b94043ca8835bd1e67749020e839f396a1c2",
"lessThan": "d3011d1f293478c730aa0870490afa145c37600e",
"versionType": "git"
},
{
"status": "affected",
"version": "23d2b94043ca8835bd1e67749020e839f396a1c2",
"lessThan": "e3206419bdb04e2087d8cc6be324df8639b3fac5",
"versionType": "git"
},
{
"status": "affected",
"version": "23d2b94043ca8835bd1e67749020e839f396a1c2",
"lessThan": "2987ee196c88dbde0463dc87d5fb209c684e34a2",
"versionType": "git"
},
{
"status": "affected",
"version": "b24065948ae6c48c9e20891f8cfe9850f1d748be",
"versionType": "git"
},
{
"status": "affected",
"version": "e9924c4204ede999b0515fd31a370a1e27f676bc",
"versionType": "git"
},
{
"status": "affected",
"version": "78967749984cf3614de346c90f3e259ff8272735",
"versionType": "git"
},
{
"status": "affected",
"version": "4768973dffed4d0126854514335ed4fe87bec1ab",
"versionType": "git"
},
{
"status": "affected",
"version": "d84708451d9041dff8a81e3718f821f12d2eb6c5",
"versionType": "git"
},
{
"status": "affected",
"version": "ddd7e8b7b84836c584a284b98ca9bd7a348a0558",
"versionType": "git"
},
{
"status": "affected",
"version": "961447ff60291b91e27d5c32fa549c1411ad3b70",
"versionType": "git"
},
{
"status": "affected",
"version": "d1a3c6d5925a8d00a32c5ef2d674dd9c0ce89c95",
"versionType": "git"
},
{
"status": "affected",
"version": "4.4.284",
"lessThan": "4.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.9.283",
"lessThan": "4.10",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.14.247",
"lessThan": "4.15",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.19.207",
"lessThan": "4.20",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.4.145",
"lessThan": "5.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.10.64",
"lessThan": "5.11",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.13.16",
"lessThan": "5.14",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.14.3",
"lessThan": "5.15",
"versionType": "semver"
}
],
"programFiles": [
"include/linux/igmp.h",
"net/ipv4/igmp.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.15",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/linux/igmp.h",
"net/ipv4/igmp.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98103
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #48853 · Revision 1
- Added to Heist Feed
- Publisher date