net/sched: sch_fq_codel: Do not call qdisc_tree_reduce_backlog during peek before restoring qlen
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: dffffc
CVE-2026-80630
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-80630
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "cc71a757da78dd4aa1b4a9b19cb011833730ccf2",
"lessThan": "3e515188393e62a718ccebee651ee74514104ff6",
"versionType": "git"
},
{
"status": "affected",
"version": "eda741fe155ddf5ecd2dd3bfbd4fc3c0c7dbb450",
"lessThan": "20dd591d8f951e1e6aca5052be8785e6181055e2",
"versionType": "git"
},
{
"status": "affected",
"version": "829c49b6b2ff45b043739168fd1245e4e1a91a30",
"lessThan": "94a5f1efdefb01f82cd228bf4e7ef1e8fc075c80",
"versionType": "git"
},
{
"status": "affected",
"version": "2f9761a94bae33d26e6a81b31b36e7d776d93dc1",
"lessThan": "acc08a0c7f37ebb1901144e03a7cba7d4afd9203",
"versionType": "git"
},
{
"status": "affected",
"version": "4d55144b12e742404bb3f8fee6038bafbf45619d",
"lessThan": "7c09843fd2b44d9bf0de798683861d1aecd62a08",
"versionType": "git"
},
{
"status": "affected",
"version": "342debc12183b51773b3345ba267e9263bdfaaef",
"lessThan": "0500af8630c3253f0dde879bd3a73a06bb2f2b3f",
"versionType": "git"
},
{
"status": "affected",
"version": "342debc12183b51773b3345ba267e9263bdfaaef",
"lessThan": "af54df2f44d9605614bc7ed96640302a240a9a62",
"versionType": "git"
},
{
"status": "affected",
"version": "342debc12183b51773b3345ba267e9263bdfaaef",
"lessThan": "097f6fc7b1ae362dd7a9444b2572162fda73b284",
"versionType": "git"
},
{
"status": "affected",
"version": "7a742a9506849d1c1aa71e36c89855ceddc7d58e",
"versionType": "git"
},
{
"status": "affected",
"version": "e73c838c80dccb9e4f19becc11d9f3cb4a27d483",
"versionType": "git"
},
{
"status": "affected",
"version": "a57fe60ef4cf96bfbb6b58397ec28bdb5a5c6b31",
"versionType": "git"
},
{
"status": "affected",
"version": "5.10.241",
"lessThan": "5.10.261",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.15.190",
"lessThan": "5.15.212",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.1.135",
"lessThan": "6.1.178",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.6.88",
"lessThan": "6.6.145",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.12.24",
"lessThan": "6.12.97",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.4.297",
"lessThan": "5.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.13.12",
"lessThan": "6.14",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.14.3",
"lessThan": "6.15",
"versionType": "semver"
}
],
"programFiles": [
"net/sched/sch_fq_codel.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.15",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/sched/sch_fq_codel.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-80630
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #34349 · Revision 1
- Added to Heist Feed
- Publisher date