openvswitch: fix soft lockup in the netlink flow dump
In the Linux kernel, the following vulnerability has been resolved: openvswitch: fix soft lockup in the netlink flow dump A production compute node carrying a few thousand datapath flows hit a soft lockup inside a single netlink flow dump and panicked. ovs_flow_cmd_dump() calls ovs_flow_stats_get() for every flow it emits, and that releases stats->lock with spin_unlock_bh() once per CPU that has touched the flow. Every release is a local_bh_enable(), and each one runs the pending softirq backlog in the dumping thread's own context. The skb bounds the flows one callback emits, but not the softirq work it absorbs. On a CPU that carries the box's packet load the backlog refills as fast as it drains, so the dumping thread becomes that CPU's softirq engine. It never sleeps and it has no reschedule point, so under voluntary preemption nothing can take the CPU away from it: neither the ksoftirqd the kernel woke to take the work over, nor the stopper thread the softlockup detector dispatches to refresh its timestamp. Hold BH off across the whole callback instead, the way ctnetlink_dump_table() does, so the nested spin_unlock_bh() stop draining softirqs. The loop already runs under rcu_read_lock() and cannot sleep. What it gives up is preemption under CONFIG_PREEMPT, since a BH-off region is not preemptible outside PREEMPT_RT. The region stays short: the skb caps the flows one callback emits, and empty buckets cost no skb space but are each visited once per dump, as the cursor only mo
CVE-2026-99025
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-2026-99025
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": "63e7959c4b9bd6f791061c460a22d9ee32ae2240",
"lessThan": "c995c52eba1926a5e82823fa5573a6f1b1010e5d",
"versionType": "git"
},
{
"status": "affected",
"version": "63e7959c4b9bd6f791061c460a22d9ee32ae2240",
"lessThan": "b872de585edff534056c65ba30970b68499fca14",
"versionType": "git"
},
{
"status": "affected",
"version": "63e7959c4b9bd6f791061c460a22d9ee32ae2240",
"lessThan": "55f12552b00a34ca7ab5cf2d2b5ed02f8f06a965",
"versionType": "git"
},
{
"status": "affected",
"version": "63e7959c4b9bd6f791061c460a22d9ee32ae2240",
"lessThan": "80db24f3c16fdeef85460d9d66a4aae7a9cb92b4",
"versionType": "git"
},
{
"status": "affected",
"version": "63e7959c4b9bd6f791061c460a22d9ee32ae2240",
"lessThan": "aaaaf87ea99b8766c9a8aa0e71aa42e6bc8a5320",
"versionType": "git"
}
],
"programFiles": [
"net/openvswitch/datapath.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.113",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.57",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.11",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/openvswitch/datapath.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-99025
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #52861 · Revision 1
- Added to Heist Feed
- Publisher date