{"id":"CVE-2026-72035","state":"PUBLISHED","title":"net/sched: sch_taprio: Replace direct dequeue call with peek and qdisc_dequeue_peeked","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_taprio: Replace direct dequeue call with peek and qdisc_dequeue_peeked\n\nWhen taprio's software path peeks a non-work-conserving child qdisc, the\nchild stashes the peeked skb in its gso_skb; taprio_dequeue_from_txq()\nthen takes the packet with a direct child ->dequeue() call, which ignores\nthat stash, orphans the peeked skb and desyncs the child's qlen/backlog.\nWith a qfq child this re-enters the child on an emptied list and\ndereferences NULL, panicking the kernel from softirq on ordinary egress.\n\nTake the packet through qdisc_dequeue_peeked(), as sch_red and sch_sfb\nnow do. The helper returns the child's stashed skb first and is a no-op\nwhen there is none, so a work-conserving child is unaffected and the\ngated path now consumes the skb whose length was charged to the budget.","publishedAt":"2026-08-15T05:51:56.374Z","updatedAt":"2026-10-19T21:19:23.999Z","severity":{"score":8.2,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"51f8af240aed903e988755af33d7491030b50ae9","versionType":"git"},{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"17ab5f76f3899f67e5569722f334591f4b88b17b","versionType":"git"},{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"f60d5c12e0551012cee5c272b0bcbcc78f7bb506","versionType":"git"},{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"6ee5a7665a9080bcb05d703bf981a579436fd05e","versionType":"git"},{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"18d580cb00c55805633bae45e90cf22ed6b8e424","versionType":"git"},{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"e2b7ee61989f2d39df6c2cc06f9db1aea69bdb09","versionType":"git"},{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"2dcebbd1ad2e180fe7b98bf346ced69a872e11e6","versionType":"git"},{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"e056e1dfcddca877dd46d704e8ec9860cfc9ec44","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/sch_taprio.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.20","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.20","versionType":"semver"},{"version":"5.10.266","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.217","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.184","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","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_taprio.c"]}],"references":["https://git.kernel.org/stable/c/51f8af240aed903e988755af33d7491030b50ae9","https://git.kernel.org/stable/c/17ab5f76f3899f67e5569722f334591f4b88b17b","https://git.kernel.org/stable/c/f60d5c12e0551012cee5c272b0bcbcc78f7bb506","https://git.kernel.org/stable/c/6ee5a7665a9080bcb05d703bf981a579436fd05e","https://git.kernel.org/stable/c/18d580cb00c55805633bae45e90cf22ed6b8e424","https://git.kernel.org/stable/c/e2b7ee61989f2d39df6c2cc06f9db1aea69bdb09","https://git.kernel.org/stable/c/2dcebbd1ad2e180fe7b98bf346ced69a872e11e6","https://git.kernel.org/stable/c/e056e1dfcddca877dd46d704e8ec9860cfc9ec44"],"weaknesses":["CWE-476"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72035.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72035","state":"PUBLISHED","datePublished":"2026-08-15T05:51:56.374Z","dateUpdated":"2026-10-19T21:19:23.999Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.901Z"},"containers":{"cna":{"title":"net/sched: sch_taprio: Replace direct dequeue call with peek and qdisc_dequeue_peeked","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_taprio: Replace direct dequeue call with peek and qdisc_dequeue_peeked\n\nWhen taprio's software path peeks a non-work-conserving child qdisc, the\nchild stashes the peeked skb in its gso_skb; taprio_dequeue_from_txq()\nthen takes the packet with a direct child ->dequeue() call, which ignores\nthat stash, orphans the peeked skb and desyncs the child's qlen/backlog.\nWith a qfq child this re-enters the child on an emptied list and\ndereferences NULL, panicking the kernel from softirq on ordinary egress.\n\nTake the packet through qdisc_dequeue_peeked(), as sch_red and sch_sfb\nnow do. The helper returns the child's stashed skb first and is a no-op\nwhen there is none, so a work-conserving child is unaffected and the\ngated path now consumes the skb whose length was charged to the budget."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"51f8af240aed903e988755af33d7491030b50ae9","versionType":"git"},{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"17ab5f76f3899f67e5569722f334591f4b88b17b","versionType":"git"},{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"f60d5c12e0551012cee5c272b0bcbcc78f7bb506","versionType":"git"},{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"6ee5a7665a9080bcb05d703bf981a579436fd05e","versionType":"git"},{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"18d580cb00c55805633bae45e90cf22ed6b8e424","versionType":"git"},{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"e2b7ee61989f2d39df6c2cc06f9db1aea69bdb09","versionType":"git"},{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"2dcebbd1ad2e180fe7b98bf346ced69a872e11e6","versionType":"git"},{"version":"5a781ccbd19e4664babcbe4b4ead7aa2b9283d22","status":"affected","lessThan":"e056e1dfcddca877dd46d704e8ec9860cfc9ec44","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/sch_taprio.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.20","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.20","versionType":"semver"},{"version":"5.10.266","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.217","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.184","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","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_taprio.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/51f8af240aed903e988755af33d7491030b50ae9"},{"url":"https://git.kernel.org/stable/c/17ab5f76f3899f67e5569722f334591f4b88b17b"},{"url":"https://git.kernel.org/stable/c/f60d5c12e0551012cee5c272b0bcbcc78f7bb506"},{"url":"https://git.kernel.org/stable/c/6ee5a7665a9080bcb05d703bf981a579436fd05e"},{"url":"https://git.kernel.org/stable/c/18d580cb00c55805633bae45e90cf22ed6b8e424"},{"url":"https://git.kernel.org/stable/c/e2b7ee61989f2d39df6c2cc06f9db1aea69bdb09"},{"url":"https://git.kernel.org/stable/c/2dcebbd1ad2e180fe7b98bf346ced69a872e11e6"},{"url":"https://git.kernel.org/stable/c/e056e1dfcddca877dd46d704e8ec9860cfc9ec44"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","baseScore":8.2,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - The fault is in taprio's software egress dequeue path (`__dev_queue_xmit` → `__qdisc_run` → `taprio_dequeue` → `taprio_dequeue_from_txq`) during ordinary packet transmission in softirq; on TSN/automotive/industrial gateways where taprio+qfq is already deployed, any remote peer can trigger it by sending traffic that causes egress through the gated queues.\nAC:L - Once taprio is configured with a non-work-conserving child such as qfq on the software path (no full offload, TXTIME_ASSIST disabled), peek followed by the incorrect direct `dequeue()` deterministically orphans the stashed skb, desyncs qlen/backlog, and re-enters qfq on an emptied list; the attacker fully controls triggering traffic with no uncontrollable races.\nPR:N - Installing taprio and grafting a qfq child requires CAP_NET_ADMIN via RTM_NEWQDISC, but on reasonably deployed TSN/industrial systems where operators have already configured this stack, triggering the bug requires only the ability to send packets through the affected interface—no credentials or capabilities on the victim host.\nUI:N - Exploitation needs only attacker-generated network traffic (or any local sender) once the qdisc hierarchy exists; no victim login, mount, file open, or other interactive action is required at trigger time.\nS:U - The NULL dereference kernel panic and qdisc qlen/backlog corruption occur entirely within the host kernel's security authority; this is not a VM escape, container breakout, or IOMMU/DMA boundary bypass.\nC:N - The published failure mode is a NULL pointer dereference in qfq after taprio mishandles the peek stash; although the peeked skb is orphaned and child counters desync, there is no use-after-free, out-of-bounds read, or demonstrated arbitrary kernel memory disclosure primitive.\nI:L - Calling `child->ops->dequeue()` instead of `qdisc_dequeue_peeked()` orphans the peek-stashed skb and corrupts the child qdisc's qlen/backlog accounting before the fatal qfq re-entry, enabling attacker-driven mis-accounting of queued traffic on the affected egress path prior to panic.\nA:H - With a qfq child the desynchronized dequeue path dereferences NULL from softirq during ordinary egress, panicking the kernel; the condition is repeatable whenever gated transmission exercises the peek/dequeue mismatch, causing total host availability loss."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-23T12:46:29.870Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"5.10.266"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"5.15.217"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.1.184"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-72035","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:50:28.139127Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-476","lang":"en","type":"CWE","description":"CWE-476 NULL Pointer Dereference"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T21:19:23.999Z"}}]}}}