{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74266", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.878Z", "datePublished": "2026-08-15T05:57:41.611Z", "dateUpdated": "2026-08-17T05:16:08.881Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:16:08.881Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_dualpi2: Do not call qdisc_tree_reduce_backlog during peek before restoring qlen\n\nWhenever dualpi2 drops packets during peek, it calls\nqdisc_tree_reduce_backlog. An issue arises because it calls\nqdisc_tree_reduce_backlog before it reincrements the qlen. If qlen drops\nto zero, but peek returns an skb, the parent's qlen_notify callback will be\nexecuted even though dualpi2 still has 1 packet on the queue and, thus,\nmistakenly deactivates the parent's class which leads to a null-ptr-deref:\n\n[ 101.427314][ T599] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] SMP KASAN NOPTI\n[ 101.427755][ T599] KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f]\n[ 101.428048][ T599] CPU: 2 UID: 0 PID: 599 Comm: ping Not tainted 7.1.0-rc5-00284-gbce53c430ed7 #102 PREEMPT(full)\n[ 101.428400][ T599] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011\n[ 101.428608][ T599] RIP: 0010:qfq_dequeue (net/sched/sch_qfq.c:1150) sch_qfq\n[ 101.428821][ T599] Code: 00 fc ff df 80 3c 02 00 0f 85 46 0c 00 00 4c 8d 73 48 48 89 9d b8 02 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 2d 0c 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b\nAll code\n[ 101.429348][ T599] RSP: 0018:ffff8881110df4f0 EFLAGS: 00010216\n[ 101.429541][ T599] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: dffffc0000000000\n[ 101.429763][ T599] RDX: 0000000000000009 RSI: 00000024c0000000 RDI: ffff88811436c2b0\n[ 101.429985][ T599] RBP: ffff88811436c000 R08: ffff88811436c280 R09: 1ffff11021277523\n[ 101.430206][ T599] R10: 1ffff11021277526 R11: 1ffff11021277527 R12: 00000024c0000000\n[ 101.430423][ T599] R13: ffff88811436c2b8 R14: 0000000000000048 R15: 0000000020000000\n[ 101.430642][ T599] FS: 00007f61813e1c40(0000) GS:ffff8881691ef000(0000) knlGS:0000000000000000\n[ 101.430913][ T599] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 101.431100][ T599] CR2: 00005651650850a8 CR3: 000000010ca0b000 CR4: 0000000000750ef0\n[ 101.431320][ T599] PKRU: 55555554\n[ 101.431433][ T599] Call Trace:\n[ 101.431544][ T599] \n[ 101.431628][ T599] __qdisc_run (net/sched/sch_generic.c:322 net/sched/sch_generic.c:427 net/sched/sch_generic.c:445)\n[ 101.431792][ T599] ? dev_qdisc_enqueue (./include/trace/events/qdisc.h:49 (discriminator 22) net/core/dev.c:4176 (discriminator 22))\n[ 101.431941][ T599] __dev_queue_xmit (./include/net/pkt_sched.h:120 ./include/net/pkt_sched.h:117 net/core/dev.c:4292 net/core/dev.c:4831)\n\nFix this by only calling qdisc_tree_reduce_backlog in peek after the\nqlen is restored." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/sch_dualpi2.c" ], "versions": [ { "version": "8f9516daedd67097a0c6e463fcb7a42b5ee9d477", "lessThan": "bd851b10daee7199a658458b8ce250e95a334500", "status": "affected", "versionType": "git" }, { "version": "8f9516daedd67097a0c6e463fcb7a42b5ee9d477", "lessThan": "466f29477cae2bd1982a066d518a9b20c5a37924", "status": "affected", "versionType": "git" }, { "version": "8f9516daedd67097a0c6e463fcb7a42b5ee9d477", "lessThan": "15cd0c93bf4f892d66bc7a93667e2357b5673365", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/sch_dualpi2.c" ], "versions": [ { "version": "6.17", "status": "affected" }, { "version": "0", "lessThan": "6.17", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "6.17", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/bd851b10daee7199a658458b8ce250e95a334500" }, { "url": "https://git.kernel.org/stable/c/466f29477cae2bd1982a066d518a9b20c5a37924" }, { "url": "https://git.kernel.org/stable/c/15cd0c93bf4f892d66bc7a93667e2357b5673365" } ], "title": "net/sched: sch_dualpi2: Do not call qdisc_tree_reduce_backlog during peek before restoring qlen", "x_generator": { "engine": "bippy-1.2.0" } } } }