net: bridge: mdb: restart port group walk after deletion
In the Linux kernel, the following vulnerability has been resolved: net: bridge: mdb: restart port group walk after deletion br_mdb_flush_pgs() keeps a pointer-to-pointer cursor while walking mp->ports. br_multicast_del_pg() can re-enter the same MDB entry through br_multicast_sg_del_exclude_ports() and unlink other port groups. If the cursor points into one of those groups, the next iteration dereferences a stale cursor and can leave mp->ports pointing at freed memory. A following RTM_GETMDB exposes the dangling pointer: BUG: KASAN: slab-use-after-free in br_mdb_dump Read of size 8 br_mdb_dump rtnl_mdb_dump rtnl_dumpit netlink_dump Reset the cursor to mp->ports after every deletion. The deletion removes at least the selected group, so the restarted walk always makes progress.
CVE-2026-98487
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-2026-98487
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": "a6acb535afb2a3b688a7858f05b61f0433e480d5",
"lessThan": "46ec55855c972504258c371677ac039ba20e5d12",
"versionType": "git"
},
{
"status": "affected",
"version": "a6acb535afb2a3b688a7858f05b61f0433e480d5",
"lessThan": "ab3c4a4c85f2e1e8d04b5c1770dea8412d21c7fe",
"versionType": "git"
},
{
"status": "affected",
"version": "a6acb535afb2a3b688a7858f05b61f0433e480d5",
"lessThan": "fe2a42789c12eb7c5d3a42191e2cc735a6c35ead",
"versionType": "git"
},
{
"status": "affected",
"version": "a6acb535afb2a3b688a7858f05b61f0433e480d5",
"lessThan": "ab1404ac81154a89fb61ac50ae9a04cd8d4834dc",
"versionType": "git"
}
],
"programFiles": [
"net/bridge/br_mdb.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.8"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.8",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.55",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.9",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/bridge/br_mdb.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98487
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #55602 · Revision 1
- Added to Heist Feed
- Publisher date