virtio_net: Fix UAF on dst_ops when IFF_XMIT_DST_RELEASE is cleared and napi_tx is false
In the Linux kernel, the following vulnerability has been resolved: virtio_net: Fix UAF on dst_ops when IFF_XMIT_DST_RELEASE is cleared and napi_tx is false A UAF issue occurs when the virtio_net driver is configured with napi_tx=N and the device's IFF_XMIT_DST_RELEASE flag is cleared (e.g., during the configuration of tc route filter rules). When IFF_XMIT_DST_RELEASE is removed from the net_device, the network stack expects the driver to hold the reference to skb->dst until the packet is fully transmitted and freed. In virtio_net with napi_tx=N, skbs may remain in the virtio transmit ring for an extended period. If the network namespace is destroyed while these skbs are still pending, the corresponding dst_ops structure has freed. When a subsequent packet is transmitted, free_old_xmit() is triggered to clean up old skbs. It then calls dst_release() on the skb associated with the stale dst_entry. Since the dst_ops (referenced by the dst_entry) has already been freed, a UAF kernel paging request occurs. fix it by adds skb_dst_drop(skb) in start_xmit to explicitly release the dst reference before the skb is queued in virtio_net. Call Trace: Unable to handle kernel paging request at virtual address ffff80007e150000 CPU: 2 UID: 0 PID: 6236 Comm: ping Kdump: loaded Not tainted 7.0.0-rc1+ #6 PREEMPT ... percpu_counter_add_batch+0x3c/0x158 lib/percpu_counter.c:98 (P) dst_release+0xe0/0x110 net/core/dst.c:177 skb_release_head_state+0xe8/0x108 net/core/skbuff.c:1177 sk_skb_reason_drop
CVE-2026-31469
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-2026-31469
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": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36",
"lessThan": "be0e63f3b97bbaf453c542e8a15ba2a536e2ac01",
"versionType": "git"
},
{
"status": "affected",
"version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36",
"lessThan": "c1ec36cb3768574b916f20d2d7415fd14fa1bf12",
"versionType": "git"
},
{
"status": "affected",
"version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36",
"lessThan": "8a4790850e710fd6771e4d2112168ed1dd6c0e54",
"versionType": "git"
},
{
"status": "affected",
"version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36",
"lessThan": "fedd2e1630cac920844997227ccbe7b26a76375a",
"versionType": "git"
},
{
"status": "affected",
"version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36",
"lessThan": "f04733c4dc40c43899c3d1c97afbae5831a3770f",
"versionType": "git"
},
{
"status": "affected",
"version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36",
"lessThan": "9a18629f2525781f0f3dda7be72b204e4cf77d08",
"versionType": "git"
},
{
"status": "affected",
"version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36",
"lessThan": "63d45077b97bb0e0fe0c75931acbbca7a47af141",
"versionType": "git"
},
{
"status": "affected",
"version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36",
"lessThan": "ba8bda9a0896746053aa97ac6c3e08168729172c",
"versionType": "git"
}
],
"programFiles": [
"drivers/net/virtio_net.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.26"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.26",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.253",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.203",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.168",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.131",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.80",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.21",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "6.19.11",
"versionType": "semver",
"lessThanOrEqual": "6.19.*"
},
{
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/net/virtio_net.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-31469
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #39886 · Revision 1
- Added to Heist Feed
- Publisher date