CVE-2026-74266

{"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] <TASK>\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"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/sched/sch_dualpi2.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "bd851b10daee7199a658458b8ce250e95a334500", "status": "affected", "version": "8f9516daedd67097a0c6e463fcb7a42b5ee9d477", "versionType": "git"}, {"lessThan": "466f29477cae2bd1982a066d518a9b20c5a37924", "status": "affected", "version": "8f9516daedd67097a0c6e463fcb7a42b5ee9d477", "versionType": "git"}, {"lessThan": "15cd0c93bf4f892d66bc7a93667e2357b5673365", "status": "affected", "version": "8f9516daedd67097a0c6e463fcb7a42b5ee9d477", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/sched/sch_dualpi2.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.17"}, {"lessThan": "6.17", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.40", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "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] <TASK>\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."}], "id": "CVE-2026-74266", "lastModified": "2026-08-17T06:19:20.190", "metrics": {}, "published": "2026-08-15T06:22:25.920", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/15cd0c93bf4f892d66bc7a93667e2357b5673365"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/466f29477cae2bd1982a066d518a9b20c5a37924"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/bd851b10daee7199a658458b8ce250e95a334500"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: net/sched: sch_dualpi2: Do not call qdisc_tree_reduce_backlog during peek before restoring qlen", "id": "2516886", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2516886"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-476", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nnet/sched: sch_dualpi2: Do not call qdisc_tree_reduce_backlog during peek before restoring qlen\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[ 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] <TASK>\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)\nFix this by only calling qdisc_tree_reduce_backlog in peek after the\nqlen is restored.", "A flaw was found in the Linux kernel's `sch_dualpi2` network scheduler. When the scheduler processes network packets, it can incorrectly manage its internal queue length. This mismanagement can lead to a system crash, making the system unavailable (Denial of Service)."], "name": "CVE-2026-74266", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-15T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-74266\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74266\nhttps://lore.kernel.org/linux-cve-announce/2026081543-CVE-2026-74266-1cd6@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8f9516daedd67097a0c6e463fcb7a42b5ee9d477,bd851b10daee7199a658458b8ce250e95a334500)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8f9516daedd67097a0c6e463fcb7a42b5ee9d477,466f29477cae2bd1982a066d518a9b20c5a37924)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8f9516daedd67097a0c6e463fcb7a42b5ee9d477,15cd0c93bf4f892d66bc7a93667e2357b5673365)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "6.17"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.17)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.40,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.5,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-15T17:15:03.021529+00:00", "updated": "2026-08-22T02:30:17.190029+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-476"]}