CVE-2026-80630
- Source
- https://cve.org/CVERecord?id=CVE-2026-80630
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80630.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-80630
- Downstream
- Published
- 2026-08-28T06:48:46Z
- Modified
- 2026-10-08T02:52:02Z
- Severity
-
- 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
- Summary
- net/sched: sch_fq_codel: Do not call qdisc_tree_reduce_backlog during peek before restoring qlen
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_fq_codel: Do not call qdisc_tree_reduce_backlog during peek before restoring qlen
Whenever fq_codel drops packets during peek, it calls qdisc_tree_reduce_backlog. An issue arises because it calls qdisc_tree_reduce_backlog before it reincrements the qlen. If qlen drops to zero, but peek returns an skb, the parent's qlen_notify callback will be executed even though fq_codel still has 1 packet on the queue and, thus, will mistakenly deactivate the parent's class causing issues like a recent report [1] and a wild memory access in qfq:
[ 29.371146][ T360] Oops: general protection fault, probably for non-canonical address 0xfbd59c0000000024: 0000 [#1] SMP KASAN NOPTI [ 29.371666][ T360] KASAN: maybe wild-memory-access in range [0xdead000000000120-0xdead000000000127] [ 29.371987][ T360] CPU: 6 UID: 0 PID: 360 Comm: tc Not tainted 7.1.0-rc5-00285-gc530e5b2dbc6-dirty #82 PREEMPT(full) [ 29.372384][ T360] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 29.372620][ T360] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:1029 (discriminator 2) include/linux/list.h:1043 (discriminator 2) net/sched/sch_qfq.c:1369 (discriminator 2) net/sched/sch_qfq.c:1395 (discriminator 2)) sch_qfq [ 29.373544][ T360] RSP: 0018:ffff888102417370 EFLAGS: 00010216 [ 29.373800][ T360] RAX: 0000000000000000 RBX: ffff88811224d568 RCX: dffffc0000000000 [ 29.374079][ T360] RDX: 1ffff11021fe1543 RSI: ffff88810ff0aa00 RDI: dffffc0000000000 [ 29.374368][ T360] RBP: ffff88811224c280 R08: dead000000000122 R09: 1bd5a00000000024 [ 29.374649][ T360] R10: fffffbfff7940329 R11: fffffbfff7940329 R12: 0000000000000000 [ 29.374926][ T360] R13: dead000000000100 R14: ffff88811224d580 R15: ffff88811224d578 [ 29.375207][ T360] FS: 00007f5b794e5780(0000) GS:ffff88815d1e9000(0000) knlGS:0000000000000000 [ 29.375545][ T360] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.375823][ T360] CR2: 000055ffb091f000 CR3: 000000010a305000 CR4: 0000000000750ef0 [ 29.376103][ T360] PKRU: 55555554 [ 29.376258][ T360] Call Trace: [ 29.376401][ T360] ... [ 29.376885][ T360] qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1487) sch_qfq [ 29.377074][ T360] qdisc_reset (net/sched/sch_generic.c:1057) [ 29.377414][ T360] __qdisc_destroy (net/sched/sch_generic.c:1096) [ 29.377600][ T360] qdisc_graft (net/sched/sch_api.c:1062 net/sched/sch_api.c:1053 net/sched/sch_api.c:1159) [ 29.378593][ T360] tc_get_qdisc (net/sched/sch_api.c:1528 net/sched/sch_api.c:1556)
Fix this by only calling qdisc_tree_reduce_backlog in peek after the qlen is restored.
[1] http://lore.kernel.org/netdev/CAN2cbVe79oj0O9==m4+4x3v+O+qzRagA=2=wkrp9i9=CqYvyZA@mail.gmail.com/
- Database specific
{ "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80630.json" }- References
-
- https://git.kernel.org/stable/c/0500af8630c3253f0dde879bd3a73a06bb2f2b3f
- https://git.kernel.org/stable/c/097f6fc7b1ae362dd7a9444b2572162fda73b284
- https://git.kernel.org/stable/c/20dd591d8f951e1e6aca5052be8785e6181055e2
- https://git.kernel.org/stable/c/3e515188393e62a718ccebee651ee74514104ff6
- https://git.kernel.org/stable/c/7c09843fd2b44d9bf0de798683861d1aecd62a08
- https://git.kernel.org/stable/c/94a5f1efdefb01f82cd228bf4e7ef1e8fc075c80
- https://git.kernel.org/stable/c/acc08a0c7f37ebb1901144e03a7cba7d4afd9203
- https://git.kernel.org/stable/c/af54df2f44d9605614bc7ed96640302a240a9a62
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80630.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-80630
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedcc71a757da78dd4aa1b4a9b19cb011833730ccf2Fixed3e515188393e62a718ccebee651ee74514104ff6
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducededa741fe155ddf5ecd2dd3bfbd4fc3c0c7dbb450Fixed20dd591d8f951e1e6aca5052be8785e6181055e2
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced829c49b6b2ff45b043739168fd1245e4e1a91a30Fixed94a5f1efdefb01f82cd228bf4e7ef1e8fc075c80
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced2f9761a94bae33d26e6a81b31b36e7d776d93dc1Fixedacc08a0c7f37ebb1901144e03a7cba7d4afd9203
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced4d55144b12e742404bb3f8fee6038bafbf45619dFixed7c09843fd2b44d9bf0de798683861d1aecd62a08
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced342debc12183b51773b3345ba267e9263bdfaaefFixed0500af8630c3253f0dde879bd3a73a06bb2f2b3fFixedaf54df2f44d9605614bc7ed96640302a240a9a62Fixed097f6fc7b1ae362dd7a9444b2572162fda73b284
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced5.10.241Fixed5.10.261
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced5.15.190Fixed5.15.212
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced6.1.135Fixed6.1.178
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced6.6.88Fixed6.6.145
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced6.12.24Fixed6.12.97
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced5.4.297Fixed5.5
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced6.13.12Fixed6.14
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced6.14.3Fixed6.15
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced7a742a9506849d1c1aa71e36c89855ceddc7d58e
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducede73c838c80dccb9e4f19becc11d9f3cb4a27d483
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduceda57fe60ef4cf96bfbb6b58397ec28bdb5a5c6b31
Affected versions
v5.*
v6.*
Linux / Kernel
Package
- Name
- Kernel
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affectedFixed5.10.261
- Type
- ECOSYSTEM
- Events
-
Introduced5.11.0Fixed5.15.212
- Type
- ECOSYSTEM
- Events
-
Introduced5.16.0Fixed6.1.178
- Type
- ECOSYSTEM
- Events
-
Introduced6.2.0Fixed6.6.145
- Type
- ECOSYSTEM
- Events
-
Introduced6.7.0Fixed6.12.97
- Type
- ECOSYSTEM
- Events
-
Introduced6.13.0Fixed6.18.40
- Type
- ECOSYSTEM
- Events
-
Introduced6.15.0Fixed7.1.5