{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-31469", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.097Z", "datePublished": "2026-04-22T13:53:58.266Z", "dateUpdated": "2026-08-05T12:22:48.560Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:22:48.560Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvirtio_net: Fix UAF on dst_ops when IFF_XMIT_DST_RELEASE is cleared and napi_tx is false\n\nA UAF issue occurs when the virtio_net driver is configured with napi_tx=N\nand the device's IFF_XMIT_DST_RELEASE flag is cleared\n(e.g., during the configuration of tc route filter rules).\n\nWhen IFF_XMIT_DST_RELEASE is removed from the net_device, the network stack\nexpects the driver to hold the reference to skb->dst until the packet\nis fully transmitted and freed. In virtio_net with napi_tx=N,\nskbs may remain in the virtio transmit ring for an extended period.\n\nIf the network namespace is destroyed while these skbs are still pending,\nthe corresponding dst_ops structure has freed. When a subsequent packet\nis transmitted, free_old_xmit() is triggered to clean up old skbs.\nIt then calls dst_release() on the skb associated with the stale dst_entry.\nSince the dst_ops (referenced by the dst_entry) has already been freed,\na UAF kernel paging request occurs.\n\nfix it by adds skb_dst_drop(skb) in start_xmit to explicitly release\nthe dst reference before the skb is queued in virtio_net.\n\nCall Trace:\n Unable to handle kernel paging request at virtual address ffff80007e150000\n CPU: 2 UID: 0 PID: 6236 Comm: ping Kdump: loaded Not tainted 7.0.0-rc1+ #6 PREEMPT\n ...\n percpu_counter_add_batch+0x3c/0x158 lib/percpu_counter.c:98 (P)\n dst_release+0xe0/0x110 net/core/dst.c:177\n skb_release_head_state+0xe8/0x108 net/core/skbuff.c:1177\n sk_skb_reason_drop+0x54/0x2d8 net/core/skbuff.c:1255\n dev_kfree_skb_any_reason+0x64/0x78 net/core/dev.c:3469\n napi_consume_skb+0x1c4/0x3a0 net/core/skbuff.c:1527\n __free_old_xmit+0x164/0x230 drivers/net/virtio_net.c:611 [virtio_net]\n free_old_xmit drivers/net/virtio_net.c:1081 [virtio_net]\n start_xmit+0x7c/0x530 drivers/net/virtio_net.c:3329 [virtio_net]\n ...\n\nReproduction Steps:\nNETDEV=\"enp3s0\"\n\nconfig_qdisc_route_filter() {\n tc qdisc del dev $NETDEV root\n tc qdisc add dev $NETDEV root handle 1: prio\n tc filter add dev $NETDEV parent 1:0 \\\n\tprotocol ip prio 100 route to 100 flowid 1:1\n ip route add 192.168.1.100/32 dev $NETDEV realm 100\n}\n\ntest_ns() {\n ip netns add testns\n ip link set $NETDEV netns testns\n ip netns exec testns ifconfig $NETDEV 10.0.32.46/24\n ip netns exec testns ping -c 1 10.0.32.1\n ip netns del testns\n}\n\nconfig_qdisc_route_filter\n\ntest_ns\nsleep 2\ntest_ns" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable virtio_net transmit/free path is reached through local packet transmission plus local netlink/ethtool namespace setup on a virtio_net interface. Remote traffic alone does not provide the required control over tc/qdisc, TX NAPI state, and namespace/device lifecycle.\nAC:L - The required conditions are attacker-controllable once the attacker has the needed network administration rights: disable TX NAPI, clear IFF_XMIT_DST_RELEASE via tc route filtering, queue packets, destroy the namespace, then trigger another transmit. There is no uncontrollable race; the pending-ring timing can be induced with normal traffic.\nPR:L - The setup requires CAP_NET_ADMIN for tc/qdisc, ethtool coalescing, and net namespace/device operations. In a reasonable delegated container or network-namespace deployment with a virtio_net interface, that maps to low privileges rather than init-namespace root, and uncertainty is resolved toward higher severity.\nUI:N - No victim user action is required after the attacker has the relevant local privileges. The attacker can perform the configuration, traffic generation, namespace teardown, and retrigger steps directly.\nS:U - The bug is in the kernel networking/virtio_net path and impacts the same kernel security authority. This is not a VM escape, IOMMU bypass, or other cross-scope boundary by itself.\nC:H - This is a use-after-free involving dst_ops referenced from an skb-held dst_entry after namespace teardown. Kernel UAFs are treated as high confidentiality impact because freed object reuse can enable memory disclosure primitives.\nI:H - The stale dst_ops/percpu-counter access is memory corruption in kernel context. As a kernel UAF, it is defensibly treated as exploitable for control-flow or write-primitive development.\nA:H - The reported failure is a kernel paging request/oops in dst_release via free_old_xmit. Even without full exploitation, the UAF can crash the kernel, causing high availability impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/virtio_net.c" ], "versions": [ { "version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36", "lessThan": "be0e63f3b97bbaf453c542e8a15ba2a536e2ac01", "status": "affected", "versionType": "git" }, { "version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36", "lessThan": "c1ec36cb3768574b916f20d2d7415fd14fa1bf12", "status": "affected", "versionType": "git" }, { "version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36", "lessThan": "8a4790850e710fd6771e4d2112168ed1dd6c0e54", "status": "affected", "versionType": "git" }, { "version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36", "lessThan": "fedd2e1630cac920844997227ccbe7b26a76375a", "status": "affected", "versionType": "git" }, { "version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36", "lessThan": "f04733c4dc40c43899c3d1c97afbae5831a3770f", "status": "affected", "versionType": "git" }, { "version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36", "lessThan": "9a18629f2525781f0f3dda7be72b204e4cf77d08", "status": "affected", "versionType": "git" }, { "version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36", "lessThan": "63d45077b97bb0e0fe0c75931acbbca7a47af141", "status": "affected", "versionType": "git" }, { "version": "f2fc6a54585a1be6669613a31fbaba2ecbadcd36", "lessThan": "ba8bda9a0896746053aa97ac6c3e08168729172c", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/virtio_net.c" ], "versions": [ { "version": "2.6.26", "status": "affected" }, { "version": "0", "lessThan": "2.6.26", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.253", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.203", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.168", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.131", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.80", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.21", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.11", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "5.10.253" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "5.15.203" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "6.1.168" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "6.6.131" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "6.12.80" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "6.18.21" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "6.19.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.26", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/be0e63f3b97bbaf453c542e8a15ba2a536e2ac01" }, { "url": "https://git.kernel.org/stable/c/c1ec36cb3768574b916f20d2d7415fd14fa1bf12" }, { "url": "https://git.kernel.org/stable/c/8a4790850e710fd6771e4d2112168ed1dd6c0e54" }, { "url": "https://git.kernel.org/stable/c/fedd2e1630cac920844997227ccbe7b26a76375a" }, { "url": "https://git.kernel.org/stable/c/f04733c4dc40c43899c3d1c97afbae5831a3770f" }, { "url": "https://git.kernel.org/stable/c/9a18629f2525781f0f3dda7be72b204e4cf77d08" }, { "url": "https://git.kernel.org/stable/c/63d45077b97bb0e0fe0c75931acbbca7a47af141" }, { "url": "https://git.kernel.org/stable/c/ba8bda9a0896746053aa97ac6c3e08168729172c" } ], "title": "virtio_net: Fix UAF on dst_ops when IFF_XMIT_DST_RELEASE is cleared and napi_tx is false", "x_generator": { "engine": 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