net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked
In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked When red qdisc has children (eg qfq qdisc) whose peek() callback is qdisc_peek_dequeued(), we could get a kernel panic. When the parent of such qdiscs (eg illustrated in patch #3 as tbf) wants to retrieve an skb from its child (red in this case), it will do the following: 1a. do a peek() - and when sensing there's an skb the child can offer, then - the child in this case(red) calls its child's (qfq) peek. qfq does the right thing and will return the gso_skb queue packet. Note: if there wasnt a gso_skb entry then qfq will store it there. 1b. invoke a dequeue() on the child (red). And herein lies the problem. - red will call the child's dequeue() which will essentially just try to grab something of qfq's queue. [ 78.667668][ T363] KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f] [ 78.667927][ T363] CPU: 1 UID: 0 PID: 363 Comm: ping Not tainted 7.1.0-rc1-00033-g46f74a3f7d57-dirty #790 PREEMPT(full) [ 78.668263][ T363] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 78.668486][ T363] RIP: 0010:qfq_dequeue+0x446/0xc90 [sch_qfq] [ 78.668718][ T363] Code: 54 c0 e8 dd 90 00 f1 48 c7 c7 e0 03 54 c0 48 89 de e8 ce 90 00 f1 48 8d 7b 48 b8 ff ff 37 00 48 89 fa 48 c1 e0 2a 48 c1 ea 03 <80> 3c 02 00 74 05 e8 ef a1 e1 f1 48 8b 7b 48 48 8d 54 24 58 48 8d [ 78.669312][ T363] RSP: 0018:ffff88810de573e0 EFLAGS: 00010216
CVE-2026-43496
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-2026-43496
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": "77be155cba4e163e8bba9fd27222a8b6189ec4f7",
"lessThan": "03b0aaeba082ae981a0dfe96cdd03d02050537a1",
"versionType": "git"
},
{
"status": "affected",
"version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7",
"lessThan": "c7335f4dc0fa21f7015b910c6fc2f4d599732328",
"versionType": "git"
},
{
"status": "affected",
"version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7",
"lessThan": "45cd83c5c470ba49fe261489c8358ad7b9df7c45",
"versionType": "git"
},
{
"status": "affected",
"version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7",
"lessThan": "36aa34f42cb6842cf371f3a2d3e855d24fd57a50",
"versionType": "git"
},
{
"status": "affected",
"version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7",
"lessThan": "ce051eede433f876d322ac3550a36a3c6fc4c231",
"versionType": "git"
},
{
"status": "affected",
"version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7",
"lessThan": "8d09618840b99ef00154d3e731ce9b11e096196d",
"versionType": "git"
},
{
"status": "affected",
"version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7",
"lessThan": "587dcf970a525f543d8b5855d9f37a4ca97b76ef",
"versionType": "git"
},
{
"status": "affected",
"version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7",
"lessThan": "458d5615272d3de535748342eb68ca492343048c",
"versionType": "git"
}
],
"programFiles": [
"net/sched/sch_red.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.29"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.29",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.258",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.209",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.175",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.140",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.88",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.30",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.7",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/sched/sch_red.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-43496
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #28353 · Revision 1
- Added to Heist Feed
- Publisher date