{"id":"CVE-2024-46800","state":"PUBLISHED","title":"sch/netem: fix use after free in netem_dequeue","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsch/netem: fix use after free in netem_dequeue\n\nIf netem_dequeue() enqueues packet to inner qdisc and that qdisc\nreturns __NET_XMIT_STOLEN. The packet is dropped but\nqdisc_tree_reduce_backlog() is not called to update the parent's\nq.qlen, leading to the similar use-after-free as Commit\ne04991a48dbaf382 (\"netem: fix return value if duplicate enqueue\nfails\")\n\nCommands to trigger KASAN UaF:\n\nip link add type dummy\nip link set lo up\nip link set dummy0 up\ntc qdisc add dev lo parent root handle 1: drr\ntc filter add dev lo parent 1: basic classid 1:1\ntc class add dev lo classid 1:1 drr\ntc qdisc add dev lo parent 1:1 handle 2: netem\ntc qdisc add dev lo parent 2: handle 3: drr\ntc filter add dev lo parent 3: basic classid 3:1 action mirred egress\nredirect dev dummy0\ntc class add dev lo classid 3:1 drr\nping -c1 -W0.01 localhost # Trigger bug\ntc class del dev lo classid 1:1\ntc class add dev lo classid 1:1 drr\nping -c1 -W0.01 localhost # UaF","publishedAt":"2024-09-18T07:12:54.330Z","updatedAt":"2026-08-05T11:38:39.612Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"f0bddb4de043399f16d1969dad5ee5b984a64e7b","versionType":"git"},{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"295ad5afd9efc5f67b86c64fce28fb94e26dc4c9","versionType":"git"},{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"98c75d76187944296068d685dfd8a1e9fd8c4fdc","versionType":"git"},{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"14f91ab8d391f249b845916820a56f42cf747241","versionType":"git"},{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"db2c235682913a63054e741fe4e19645fdf2d68e","versionType":"git"},{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"dde33a9d0b80aae0c69594d1f462515d7ff1cb3d","versionType":"git"},{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"32008ab989ddcff1a485fa2b4906234c25dc5cd6","versionType":"git"},{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"3b3a2a9c6349e25a025d2330f479bc33a6ccb54a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/sch_netem.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.3","versionType":"semver"},{"version":"4.19.322","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.284","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.226","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.167","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.110","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.51","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.10.10","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/sch_netem.c"]}],"references":["https://git.kernel.org/stable/c/f0bddb4de043399f16d1969dad5ee5b984a64e7b","https://git.kernel.org/stable/c/295ad5afd9efc5f67b86c64fce28fb94e26dc4c9","https://git.kernel.org/stable/c/98c75d76187944296068d685dfd8a1e9fd8c4fdc","https://git.kernel.org/stable/c/14f91ab8d391f249b845916820a56f42cf747241","https://git.kernel.org/stable/c/db2c235682913a63054e741fe4e19645fdf2d68e","https://git.kernel.org/stable/c/dde33a9d0b80aae0c69594d1f462515d7ff1cb3d","https://git.kernel.org/stable/c/32008ab989ddcff1a485fa2b4906234c25dc5cd6","https://git.kernel.org/stable/c/3b3a2a9c6349e25a025d2330f479bc33a6ccb54a","https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html","https://lists.debian.org/debian-lts-announce/2024/10/msg00003.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:07:47.831Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/46xxx/CVE-2024-46800.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-46800","state":"PUBLISHED","datePublished":"2024-09-18T07:12:54.330Z","dateUpdated":"2026-08-05T11:38:39.612Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-09-11T15:12:18.280Z"},"containers":{"cna":{"title":"sch/netem: fix use after free in netem_dequeue","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsch/netem: fix use after free in netem_dequeue\n\nIf netem_dequeue() enqueues packet to inner qdisc and that qdisc\nreturns __NET_XMIT_STOLEN. The packet is dropped but\nqdisc_tree_reduce_backlog() is not called to update the parent's\nq.qlen, leading to the similar use-after-free as Commit\ne04991a48dbaf382 (\"netem: fix return value if duplicate enqueue\nfails\")\n\nCommands to trigger KASAN UaF:\n\nip link add type dummy\nip link set lo up\nip link set dummy0 up\ntc qdisc add dev lo parent root handle 1: drr\ntc filter add dev lo parent 1: basic classid 1:1\ntc class add dev lo classid 1:1 drr\ntc qdisc add dev lo parent 1:1 handle 2: netem\ntc qdisc add dev lo parent 2: handle 3: drr\ntc filter add dev lo parent 3: basic classid 3:1 action mirred egress\nredirect dev dummy0\ntc class add dev lo classid 3:1 drr\nping -c1 -W0.01 localhost # Trigger bug\ntc class del dev lo classid 1:1\ntc class add dev lo classid 1:1 drr\nping -c1 -W0.01 localhost # UaF"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"f0bddb4de043399f16d1969dad5ee5b984a64e7b","versionType":"git"},{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"295ad5afd9efc5f67b86c64fce28fb94e26dc4c9","versionType":"git"},{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"98c75d76187944296068d685dfd8a1e9fd8c4fdc","versionType":"git"},{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"14f91ab8d391f249b845916820a56f42cf747241","versionType":"git"},{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"db2c235682913a63054e741fe4e19645fdf2d68e","versionType":"git"},{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"dde33a9d0b80aae0c69594d1f462515d7ff1cb3d","versionType":"git"},{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"32008ab989ddcff1a485fa2b4906234c25dc5cd6","versionType":"git"},{"version":"50612537e9ab29693122fab20fc1eed235054ffe","status":"affected","lessThan":"3b3a2a9c6349e25a025d2330f479bc33a6ccb54a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/sch_netem.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.3","versionType":"semver"},{"version":"4.19.322","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.284","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.226","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.167","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.110","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.51","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.10.10","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/sch_netem.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f0bddb4de043399f16d1969dad5ee5b984a64e7b"},{"url":"https://git.kernel.org/stable/c/295ad5afd9efc5f67b86c64fce28fb94e26dc4c9"},{"url":"https://git.kernel.org/stable/c/98c75d76187944296068d685dfd8a1e9fd8c4fdc"},{"url":"https://git.kernel.org/stable/c/14f91ab8d391f249b845916820a56f42cf747241"},{"url":"https://git.kernel.org/stable/c/db2c235682913a63054e741fe4e19645fdf2d68e"},{"url":"https://git.kernel.org/stable/c/dde33a9d0b80aae0c69594d1f462515d7ff1cb3d"},{"url":"https://git.kernel.org/stable/c/32008ab989ddcff1a485fa2b4906234c25dc5cd6"},{"url":"https://git.kernel.org/stable/c/3b3a2a9c6349e25a025d2330f479bc33a6ccb54a"}],"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 - Exploitation requires configuring a netem qdisc under a DRR class with a mirred-redirect filter via rtnetlink/tc, plus a locally transmitted packet to drive the dequeue path. Per kernel guidance, tc/netlink qdisc bugs are Local.\nAC:L - The commit message supplies a deterministic KASAN reproducer with no race and no dependence on conditions outside the attacker's control; the attacker fully controls the qdisc topology, the STOLEN-returning action, the class deletion, and the reclaiming heap spray.\nPR:L - Only CAP_NET_ADMIN scoped to a network namespace is needed, which any unprivileged local user obtains with `unshare -Urn`; this is also trivially reachable from containers/sandboxes that hold CAP_NET_ADMIN in their own netns.\nUI:N - The attacker performs every step — qdisc/class setup, the triggering transmit, the class deletion, and the second transmit that touches the freed object. No victim action is involved.\nS:U - The freed drr_class and the resulting corruption stay within the kernel's own security authority; there is no VM, IOMMU, or sandbox boundary crossed.\nC:H - The stale drr_class is dereferenced after free, and reclaiming the slab slot with sprayed data lets the attacker aim cl->qdisc at arbitrary kernel memory that is then read and dereferenced, yielding kernel memory disclosure.\nI:H - The UAF gives both an indirect call through cl->qdisc->ops->peek and list_del_init()/list_move_tail() writes through attacker-controlled list pointers in the freed object — arbitrary write and control-flow hijack primitives leading to privilege escalation.\nA:H - Even without weaponization the use-after-free corrupts the DRR active list and oopses the kernel (confirmed by KASAN in the reporter's reproducer), crashing the system."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T11:38:39.612Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"4.19.322"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"5.4.284"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"5.10.226"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"5.15.167"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"6.1.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"6.6.51"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"6.10.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"6.11"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2024-09-29T14:21:46.451136Z","id":"CVE-2024-46800","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-29T14:21:58.260Z"}},{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"},{"url":"https://lists.debian.org/debian-lts-announce/2024/10/msg00003.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-03T22:18:43.054Z"}}]}}}