CVE-2026-22976 (GCVE-0-2026-22976)
Vulnerability from cvelistv5 – Published: 2026-01-21 06:57 – Updated: 2026-10-19 18:25
VLAI
EPSS
VEX
Title
net/sched: sch_qfq: Fix NULL deref when deactivating inactive aggregate in qfq_reset
Summary
In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_qfq: Fix NULL deref when deactivating inactive aggregate in qfq_reset
`qfq_class->leaf_qdisc->q.qlen > 0` does not imply that the class
itself is active.
Two qfq_class objects may point to the same leaf_qdisc. This happens
when:
1. one QFQ qdisc is attached to the dev as the root qdisc, and
2. another QFQ qdisc is temporarily referenced (e.g., via qdisc_get()
/ qdisc_put()) and is pending to be destroyed, as in function
tc_new_tfilter.
When packets are enqueued through the root QFQ qdisc, the shared
leaf_qdisc->q.qlen increases. At the same time, the second QFQ
qdisc triggers qdisc_put and qdisc_destroy: the qdisc enters
qfq_reset() with its own q->q.qlen == 0, but its class's leaf
qdisc->q.qlen > 0. Therefore, the qfq_reset would wrongly deactivate
an inactive aggregate and trigger a null-deref in qfq_deactivate_agg:
[ 0.903172] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 0.903571] #PF: supervisor write access in kernel mode
[ 0.903860] #PF: error_code(0x0002) - not-present page
[ 0.904177] PGD 10299b067 P4D 10299b067 PUD 10299c067 PMD 0
[ 0.904502] Oops: Oops: 0002 [#1] SMP NOPTI
[ 0.904737] CPU: 0 UID: 0 PID: 135 Comm: exploit Not tainted 6.19.0-rc3+ #2 NONE
[ 0.905157] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
[ 0.905754] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2))
[ 0.906046] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0
Code starting with the faulting instruction
===========================================
0: 0f 84 4d 01 00 00 je 0x153
6: 48 89 70 18 mov %rsi,0x18(%rax)
a: 8b 4b 10 mov 0x10(%rbx),%ecx
d: 48 c7 c2 ff ff ff ff mov $0xffffffffffffffff,%rdx
14: 48 8b 78 08 mov 0x8(%rax),%rdi
18: 48 d3 e2 shl %cl,%rdx
1b: 48 21 f2 and %rsi,%rdx
1e: 48 2b 13 sub (%rbx),%rdx
21: 48 8b 30 mov (%rax),%rsi
24: 48 d3 ea shr %cl,%rdx
27: 8b 4b 18 mov 0x18(%rbx),%ecx
...
[ 0.907095] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246
[ 0.907368] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000
[ 0.907723] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 0.908100] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000
[ 0.908451] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000
[ 0.908804] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880
[ 0.909179] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000
[ 0.909572] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.909857] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0
[ 0.910247] PKRU: 55555554
[ 0.910391] Call Trace:
[ 0.910527] <TASK>
[ 0.910638] qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1485)
[ 0.910826] qdisc_reset (include/linux/skbuff.h:2195 include/linux/skbuff.h:2501 include/linux/skbuff.h:3424 include/linux/skbuff.h:3430 net/sched/sch_generic.c:1036)
[ 0.911040] __qdisc_destroy (net/sched/sch_generic.c:1076)
[ 0.911236] tc_new_tfilter (net/sched/cls_api.c:2447)
[ 0.911447] rtnetlink_rcv_msg (net/core/rtnetlink.c:6958)
[ 0.911663] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6861)
[ 0.911894] netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[ 0.912100] netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[ 0.912296] ? __alloc_skb (net/core/skbuff.c:706)
[ 0.912484] netlink_sendmsg (net/netlink/af
---truncated---
Severity
No CVSS data available.
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-10 20:42 UTC
CWE
- CWE-476 - NULL Pointer Dereference
Assigner
References
8 references
Impacted products
3 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
0545a3037773512d3448557ba048cebb73b3e4af , < 6116a83ec167d3ab1390cded854d237481f41b63
(git)
Affected: 0545a3037773512d3448557ba048cebb73b3e4af , < 0809c4bc06c9c961222df29f2eccfd449304056f (git) Affected: 0545a3037773512d3448557ba048cebb73b3e4af , < cdb24200b043438a144df501f1ebbd926bb1a2c7 (git) Affected: 0545a3037773512d3448557ba048cebb73b3e4af , < 11bf9134613f6c71fc0ff36c5d8d33856f6ae3bb (git) Affected: 0545a3037773512d3448557ba048cebb73b3e4af , < 43497313d0da3e12b5cfcd97aa17bf48ee663f95 (git) Affected: 0545a3037773512d3448557ba048cebb73b3e4af , < 51ffd447bc37bf1a5776b85523f51d2bc69977f6 (git) Affected: 0545a3037773512d3448557ba048cebb73b3e4af , < c1d73b1480235731e35c81df70b08f4714a7d095 (git) |
guessed | |
| Linux | Linux |
Affected:
3.0
Unaffected: 0 , < 3.0 (semver) Unaffected: 5.10.248 , ≤ 5.10.* (semver) Unaffected: 5.15.198 , ≤ 5.15.* (semver) Unaffected: 6.1.161 , ≤ 6.1.* (semver) Unaffected: 6.6.121 , ≤ 6.6.* (semver) Unaffected: 6.12.66 , ≤ 6.12.* (semver) Unaffected: 6.18.6 , ≤ 6.18.* (semver) Unaffected: 6.19 , ≤ * (original_commit_for_fix) |
guessed | |
| Siemens | RUGGEDCOM RST2428P |
Affected:
0 , < V4.0
(custom)
|
guessed |
{
"containers": {
"adp": [
{
"affected": [
{
"defaultStatus": "unknown",
"product": "RUGGEDCOM RST2428P",
"vendor": "Siemens",
"versions": [
{
"lessThan": "V4.0",
"status": "affected",
"version": "0",
"versionType": "custom"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-06-02T13:00:46.449Z",
"orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"shortName": "siemens-SADP"
},
"references": [
{
"url": "https://cert-portal.siemens.com/productcert/html/ssa-253495.html"
}
],
"x_adpType": "supplier"
},
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-22976",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-06-10T20:42:23.375903Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-476",
"description": "CWE-476 NULL Pointer Dereference",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-10-19T18:25:25.738Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/sched/sch_qfq.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "6116a83ec167d3ab1390cded854d237481f41b63",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "0809c4bc06c9c961222df29f2eccfd449304056f",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "cdb24200b043438a144df501f1ebbd926bb1a2c7",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "11bf9134613f6c71fc0ff36c5d8d33856f6ae3bb",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "43497313d0da3e12b5cfcd97aa17bf48ee663f95",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "51ffd447bc37bf1a5776b85523f51d2bc69977f6",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "c1d73b1480235731e35c81df70b08f4714a7d095",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/sched/sch_qfq.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.0"
},
{
"lessThan": "3.0",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.248",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.198",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.161",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.121",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.66",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.19",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.248",
"versionStartIncluding": "3.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.198",
"versionStartIncluding": "3.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.161",
"versionStartIncluding": "3.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.121",
"versionStartIncluding": "3.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.66",
"versionStartIncluding": "3.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.6",
"versionStartIncluding": "3.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.19",
"versionStartIncluding": "3.0",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_qfq: Fix NULL deref when deactivating inactive aggregate in qfq_reset\n\n`qfq_class-\u003eleaf_qdisc-\u003eq.qlen \u003e 0` does not imply that the class\nitself is active.\n\nTwo qfq_class objects may point to the same leaf_qdisc. This happens\nwhen:\n\n1. one QFQ qdisc is attached to the dev as the root qdisc, and\n\n2. another QFQ qdisc is temporarily referenced (e.g., via qdisc_get()\n/ qdisc_put()) and is pending to be destroyed, as in function\ntc_new_tfilter.\n\nWhen packets are enqueued through the root QFQ qdisc, the shared\nleaf_qdisc-\u003eq.qlen increases. At the same time, the second QFQ\nqdisc triggers qdisc_put and qdisc_destroy: the qdisc enters\nqfq_reset() with its own q-\u003eq.qlen == 0, but its class\u0027s leaf\nqdisc-\u003eq.qlen \u003e 0. Therefore, the qfq_reset would wrongly deactivate\nan inactive aggregate and trigger a null-deref in qfq_deactivate_agg:\n\n[ 0.903172] BUG: kernel NULL pointer dereference, address: 0000000000000000\n[ 0.903571] #PF: supervisor write access in kernel mode\n[ 0.903860] #PF: error_code(0x0002) - not-present page\n[ 0.904177] PGD 10299b067 P4D 10299b067 PUD 10299c067 PMD 0\n[ 0.904502] Oops: Oops: 0002 [#1] SMP NOPTI\n[ 0.904737] CPU: 0 UID: 0 PID: 135 Comm: exploit Not tainted 6.19.0-rc3+ #2 NONE\n[ 0.905157] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014\n[ 0.905754] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2))\n[ 0.906046] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0\n\nCode starting with the faulting instruction\n===========================================\n 0:\t0f 84 4d 01 00 00 \tje 0x153\n 6:\t48 89 70 18 \tmov %rsi,0x18(%rax)\n a:\t8b 4b 10 \tmov 0x10(%rbx),%ecx\n d:\t48 c7 c2 ff ff ff ff \tmov $0xffffffffffffffff,%rdx\n 14:\t48 8b 78 08 \tmov 0x8(%rax),%rdi\n 18:\t48 d3 e2 \tshl %cl,%rdx\n 1b:\t48 21 f2 \tand %rsi,%rdx\n 1e:\t48 2b 13 \tsub (%rbx),%rdx\n 21:\t48 8b 30 \tmov (%rax),%rsi\n 24:\t48 d3 ea \tshr %cl,%rdx\n 27:\t8b 4b 18 \tmov 0x18(%rbx),%ecx\n\t...\n[ 0.907095] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246\n[ 0.907368] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000\n[ 0.907723] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000\n[ 0.908100] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000\n[ 0.908451] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000\n[ 0.908804] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880\n[ 0.909179] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000\n[ 0.909572] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 0.909857] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0\n[ 0.910247] PKRU: 55555554\n[ 0.910391] Call Trace:\n[ 0.910527] \u003cTASK\u003e\n[ 0.910638] qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1485)\n[ 0.910826] qdisc_reset (include/linux/skbuff.h:2195 include/linux/skbuff.h:2501 include/linux/skbuff.h:3424 include/linux/skbuff.h:3430 net/sched/sch_generic.c:1036)\n[ 0.911040] __qdisc_destroy (net/sched/sch_generic.c:1076)\n[ 0.911236] tc_new_tfilter (net/sched/cls_api.c:2447)\n[ 0.911447] rtnetlink_rcv_msg (net/core/rtnetlink.c:6958)\n[ 0.911663] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6861)\n[ 0.911894] netlink_rcv_skb (net/netlink/af_netlink.c:2550)\n[ 0.912100] netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)\n[ 0.912296] ? __alloc_skb (net/core/skbuff.c:706)\n[ 0.912484] netlink_sendmsg (net/netlink/af\n---truncated---"
}
],
"providerMetadata": {
"dateUpdated": "2026-05-11T21:57:35.535Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/6116a83ec167d3ab1390cded854d237481f41b63"
},
{
"url": "https://git.kernel.org/stable/c/0809c4bc06c9c961222df29f2eccfd449304056f"
},
{
"url": "https://git.kernel.org/stable/c/cdb24200b043438a144df501f1ebbd926bb1a2c7"
},
{
"url": "https://git.kernel.org/stable/c/11bf9134613f6c71fc0ff36c5d8d33856f6ae3bb"
},
{
"url": "https://git.kernel.org/stable/c/43497313d0da3e12b5cfcd97aa17bf48ee663f95"
},
{
"url": "https://git.kernel.org/stable/c/51ffd447bc37bf1a5776b85523f51d2bc69977f6"
},
{
"url": "https://git.kernel.org/stable/c/c1d73b1480235731e35c81df70b08f4714a7d095"
}
],
"title": "net/sched: sch_qfq: Fix NULL deref when deactivating inactive aggregate in qfq_reset",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-22976",
"datePublished": "2026-01-21T06:57:23.939Z",
"dateReserved": "2026-01-13T15:37:45.935Z",
"dateUpdated": "2026-10-19T18:25:25.738Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-22976",
"date": "2026-11-11",
"epss": "0.00181",
"percentile": "0.07728"
},
"microsoft_vex": {
"current_release_date": "2026-03-03T15:03:23.000Z",
"cve": "CVE-2026-22976",
"id": "msrc_CVE-2026-22976",
"initial_release_date": "2026-01-02T00:00:00.000Z",
"product_status:fixed": "1",
"product_status:known_affected": "1",
"source": "Microsoft CSAF VEX",
"status": "final",
"title": "net/sched: sch_qfq: Fix NULL deref when deactivating inactive aggregate in qfq_reset",
"url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-22976.json",
"version": "3"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/sched/sch_qfq.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "6116a83ec167d3ab1390cded854d237481f41b63",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "0809c4bc06c9c961222df29f2eccfd449304056f",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "cdb24200b043438a144df501f1ebbd926bb1a2c7",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "11bf9134613f6c71fc0ff36c5d8d33856f6ae3bb",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "43497313d0da3e12b5cfcd97aa17bf48ee663f95",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "51ffd447bc37bf1a5776b85523f51d2bc69977f6",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "c1d73b1480235731e35c81df70b08f4714a7d095",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/sched/sch_qfq.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.0"
},
{
"lessThan": "3.0",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.248",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.198",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.161",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.121",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.66",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.19",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"affectedData": [
{
"defaultStatus": "unknown",
"product": "RUGGEDCOM RST2428P",
"vendor": "Siemens",
"versions": [
{
"lessThan": "V4.0",
"status": "affected",
"version": "0",
"versionType": "custom"
}
]
}
],
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "F7FB331B-C639-484C-AC8F-06ACD071EE13",
"versionEndExcluding": "5.10.248",
"versionStartIncluding": "3.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "82159CAA-B6BA-43C6-85D8-65BDBC175A7E",
"versionEndExcluding": "5.15.198",
"versionStartIncluding": "5.11",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "E135B7E2-61FC-4DC1-8570-ABD67894FFDE",
"versionEndExcluding": "6.1.161",
"versionStartIncluding": "5.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "BB7A164B-7422-4A1C-82FB-5FCAEE53C06C",
"versionEndExcluding": "6.6.121",
"versionStartIncluding": "6.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "F72B884C-B44F-40E4-9895-CE421AC663D0",
"versionEndExcluding": "6.12.66",
"versionStartIncluding": "6.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "879529BC-5B4C-4EBE-BF1D-1A31404A8B2E",
"versionEndExcluding": "6.18.6",
"versionStartIncluding": "6.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*",
"matchCriteriaId": "17B67AA7-40D6-4AFA-8459-F200F3D7CFD1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*",
"matchCriteriaId": "C47E4CC9-C826-4FA9-B014-7FE3D9B318B2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*",
"matchCriteriaId": "F71D92C0-C023-48BD-B3B6-70B638EEE298",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:*",
"matchCriteriaId": "13580667-0A98-40CC-B29F-D12790B91BDB",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_qfq: Fix NULL deref when deactivating inactive aggregate in qfq_reset\n\n`qfq_class-\u003eleaf_qdisc-\u003eq.qlen \u003e 0` does not imply that the class\nitself is active.\n\nTwo qfq_class objects may point to the same leaf_qdisc. This happens\nwhen:\n\n1. one QFQ qdisc is attached to the dev as the root qdisc, and\n\n2. another QFQ qdisc is temporarily referenced (e.g., via qdisc_get()\n/ qdisc_put()) and is pending to be destroyed, as in function\ntc_new_tfilter.\n\nWhen packets are enqueued through the root QFQ qdisc, the shared\nleaf_qdisc-\u003eq.qlen increases. At the same time, the second QFQ\nqdisc triggers qdisc_put and qdisc_destroy: the qdisc enters\nqfq_reset() with its own q-\u003eq.qlen == 0, but its class\u0027s leaf\nqdisc-\u003eq.qlen \u003e 0. Therefore, the qfq_reset would wrongly deactivate\nan inactive aggregate and trigger a null-deref in qfq_deactivate_agg:\n\n[ 0.903172] BUG: kernel NULL pointer dereference, address: 0000000000000000\n[ 0.903571] #PF: supervisor write access in kernel mode\n[ 0.903860] #PF: error_code(0x0002) - not-present page\n[ 0.904177] PGD 10299b067 P4D 10299b067 PUD 10299c067 PMD 0\n[ 0.904502] Oops: Oops: 0002 [#1] SMP NOPTI\n[ 0.904737] CPU: 0 UID: 0 PID: 135 Comm: exploit Not tainted 6.19.0-rc3+ #2 NONE\n[ 0.905157] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014\n[ 0.905754] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2))\n[ 0.906046] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0\n\nCode starting with the faulting instruction\n===========================================\n 0:\t0f 84 4d 01 00 00 \tje 0x153\n 6:\t48 89 70 18 \tmov %rsi,0x18(%rax)\n a:\t8b 4b 10 \tmov 0x10(%rbx),%ecx\n d:\t48 c7 c2 ff ff ff ff \tmov $0xffffffffffffffff,%rdx\n 14:\t48 8b 78 08 \tmov 0x8(%rax),%rdi\n 18:\t48 d3 e2 \tshl %cl,%rdx\n 1b:\t48 21 f2 \tand %rsi,%rdx\n 1e:\t48 2b 13 \tsub (%rbx),%rdx\n 21:\t48 8b 30 \tmov (%rax),%rsi\n 24:\t48 d3 ea \tshr %cl,%rdx\n 27:\t8b 4b 18 \tmov 0x18(%rbx),%ecx\n\t...\n[ 0.907095] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246\n[ 0.907368] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000\n[ 0.907723] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000\n[ 0.908100] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000\n[ 0.908451] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000\n[ 0.908804] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880\n[ 0.909179] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000\n[ 0.909572] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 0.909857] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0\n[ 0.910247] PKRU: 55555554\n[ 0.910391] Call Trace:\n[ 0.910527] \u003cTASK\u003e\n[ 0.910638] qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1485)\n[ 0.910826] qdisc_reset (include/linux/skbuff.h:2195 include/linux/skbuff.h:2501 include/linux/skbuff.h:3424 include/linux/skbuff.h:3430 net/sched/sch_generic.c:1036)\n[ 0.911040] __qdisc_destroy (net/sched/sch_generic.c:1076)\n[ 0.911236] tc_new_tfilter (net/sched/cls_api.c:2447)\n[ 0.911447] rtnetlink_rcv_msg (net/core/rtnetlink.c:6958)\n[ 0.911663] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6861)\n[ 0.911894] netlink_rcv_skb (net/netlink/af_netlink.c:2550)\n[ 0.912100] netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)\n[ 0.912296] ? __alloc_skb (net/core/skbuff.c:706)\n[ 0.912484] netlink_sendmsg (net/netlink/af\n---truncated---"
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet/sched: sch_qfq: Correcci\u00f3n de desreferencia NULL al desactivar un agregado inactivo en qfq_reset\n\n\u0027qfq_class-\u0026gt;leaf_qdisc-\u0026gt;q.qlen \u0026gt; 0\u0027 no implica que la propia clase est\u00e9 activa.\n\nDos objetos qfq_class pueden apuntar al mismo leaf_qdisc. Esto ocurre cuando:\n\n1. un qdisc QFQ est\u00e1 adjunto al dev como el qdisc ra\u00edz, y\n\n2. otro qdisc QFQ es referenciado temporalmente (p. ej., a trav\u00e9s de qdisc_get() / qdisc_put()) y est\u00e1 pendiente de ser destruido, como en la funci\u00f3n tc_new_tfilter.\n\nCuando los paquetes son encolados a trav\u00e9s del qdisc QFQ ra\u00edz, el leaf_qdisc-\u0026gt;q.qlen compartido aumenta. Al mismo tiempo, el segundo qdisc QFQ dispara qdisc_put y qdisc_destroy: el qdisc entra en qfq_reset() con su propio q-\u0026gt;q.qlen == 0, pero el leaf qdisc de su clase-\u0026gt;q.qlen \u0026gt; 0. Por lo tanto, el qfq_reset desactivar\u00eda err\u00f3neamente un agregado inactivo y disparar\u00eda una desreferencia nula en qfq_deactivate_agg:\n\n[ 0.903172] BUG: kernel NULL pointer dereference, address: 0000000000000000\n[ 0.903571] #PF: supervisor write access in kernel mode\n[ 0.903860] #PF: error_code(0x0002) - not-present page\n[ 0.904177] PGD 10299b067 P4D 10299b067 PUD 10299c067 PMD 0\n[ 0.904502] Oops: Oops: 0002 [#1] SMP NOPTI\n[ 0.904737] CPU: 0 UID: 0 PID: 135 Comm: exploit Not tainted 6.19.0-rc3+ #2 NONE\n[ 0.905157] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014\n[ 0.905754] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2))\n[ 0.906046] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0\n\nC\u00f3digo que comienza con la instrucci\u00f3n que causa el fallo\n===========================================\n 0:\t0f 84 4d 01 00 00 \tje 0x153\n 6:\t48 89 70 18 \tmov %rsi,0x18(%rax)\n a:\t8b 4b 10 \tmov 0x10(%rbx),%ecx\n d:\t48 c7 c2 ff ff ff ff \tmov $0xffffffffffffffff,%rdx\n 14:\t48 8b 78 08 \tmov 0x8(%rax),%rdi\n 18:\t48 d3 e2 \tshl %cl,%rdx\n 1b:\t48 21 f2 \tand %rsi,%rdx\n 1e:\t48 2b 13 \tsub (%rbx),%rdx\n 21:\t48 8b 30 \tmov (%rax),%rsi\n 24:\t48 d3 ea \tshr %cl,%rdx\n 27:\t8b 4b 18 \tmov 0x18(%rbx),%ecx\n\t...\n[ 0.907095] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246\n[ 0.907368] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000\n[ 0.907723] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000\n[ 0.908100] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000\n[ 0.908451] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000\n[ 0.908804] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880\n[ 0.909179] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000\n[ 0.909572] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 0.909857] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0\n[ 0.910247] PKRU: 55555554\n[ 0.910391] Call Trace:\n[ 0.910527] \n[ 0.910638] qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1485)\n[ 0.910826] qdisc_reset (include/linux/skbuff.h:2195 include/linux/skbuff.h:2501 include/linux/skbuff.h:3424 include/linux/skbuff.h:3430 net/sched/sch_generic.c:1036)\n[ 0.911040] __qdisc_destroy (net/sched/sch_generic.c:1076)\n[ 0.911236] tc_new_tfilter (net/sched/cls_api.c:2447)\n[ 0.911447] rtnetlink_rcv_msg (net/core/rtnetlink.c:6958)\n[ 0.911663] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6861)\n[ 0.911894] netlink_rcv_skb (net/netlink/af_netlink.c:2550)\n[ 0.912100] netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)\n[ 0.912296] ? __alloc_skb (net/core/skbuff.c:706)\n[ 0.912484] netlink_sendmsg (net/netlink/af\n---truncated---"
}
],
"id": "CVE-2026-22976",
"lastModified": "2026-10-19T19:17:29.773",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6,
"source": "nvd@nist.gov",
"type": "Primary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-22976",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-06-10T20:42:23.375903Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-01-21T07:16:01.433",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/0809c4bc06c9c961222df29f2eccfd449304056f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/11bf9134613f6c71fc0ff36c5d8d33856f6ae3bb"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/43497313d0da3e12b5cfcd97aa17bf48ee663f95"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/51ffd447bc37bf1a5776b85523f51d2bc69977f6"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/6116a83ec167d3ab1390cded854d237481f41b63"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/c1d73b1480235731e35c81df70b08f4714a7d095"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/cdb24200b043438a144df501f1ebbd926bb1a2c7"
},
{
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-253495.html"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Modified",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-476"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
},
{
"description": [
{
"lang": "en",
"value": "CWE-476"
}
],
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2026-11-05T16:53:18+00:00",
"cve": "CVE-2026-22976",
"id": "CVE-2026-22976",
"initial_release_date": "2026-01-21T06:57:23.939000+00:00",
"product_status:known_affected": "200",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: Linux kernel: Denial of Service in sch_qfq due to NULL pointer dereference",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-22976.json",
"version": "3"
},
"vulnrichment": {
"containers": {
"adp": [
{
"affected": [
{
"defaultStatus": "unknown",
"product": "RUGGEDCOM RST2428P",
"vendor": "Siemens",
"versions": [
{
"lessThan": "V4.0",
"status": "affected",
"version": "0",
"versionType": "custom"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-06-02T13:00:46.449Z",
"orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"shortName": "siemens-SADP"
},
"references": [
{
"url": "https://cert-portal.siemens.com/productcert/html/ssa-253495.html"
}
],
"x_adpType": "supplier"
},
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-22976",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-06-10T20:42:23.375903Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-476",
"description": "CWE-476 NULL Pointer Dereference",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-06-11T17:39:21.631Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/sched/sch_qfq.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "6116a83ec167d3ab1390cded854d237481f41b63",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "0809c4bc06c9c961222df29f2eccfd449304056f",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "cdb24200b043438a144df501f1ebbd926bb1a2c7",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "11bf9134613f6c71fc0ff36c5d8d33856f6ae3bb",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "43497313d0da3e12b5cfcd97aa17bf48ee663f95",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "51ffd447bc37bf1a5776b85523f51d2bc69977f6",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
},
{
"lessThan": "c1d73b1480235731e35c81df70b08f4714a7d095",
"status": "affected",
"version": "0545a3037773512d3448557ba048cebb73b3e4af",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/sched/sch_qfq.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.0"
},
{
"lessThan": "3.0",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.248",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.198",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.161",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.121",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.66",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.19",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.248",
"versionStartIncluding": "3.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.198",
"versionStartIncluding": "3.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.161",
"versionStartIncluding": "3.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.121",
"versionStartIncluding": "3.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.66",
"versionStartIncluding": "3.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.6",
"versionStartIncluding": "3.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.19",
"versionStartIncluding": "3.0",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_qfq: Fix NULL deref when deactivating inactive aggregate in qfq_reset\n\n`qfq_class-\u003eleaf_qdisc-\u003eq.qlen \u003e 0` does not imply that the class\nitself is active.\n\nTwo qfq_class objects may point to the same leaf_qdisc. This happens\nwhen:\n\n1. one QFQ qdisc is attached to the dev as the root qdisc, and\n\n2. another QFQ qdisc is temporarily referenced (e.g., via qdisc_get()\n/ qdisc_put()) and is pending to be destroyed, as in function\ntc_new_tfilter.\n\nWhen packets are enqueued through the root QFQ qdisc, the shared\nleaf_qdisc-\u003eq.qlen increases. At the same time, the second QFQ\nqdisc triggers qdisc_put and qdisc_destroy: the qdisc enters\nqfq_reset() with its own q-\u003eq.qlen == 0, but its class\u0027s leaf\nqdisc-\u003eq.qlen \u003e 0. Therefore, the qfq_reset would wrongly deactivate\nan inactive aggregate and trigger a null-deref in qfq_deactivate_agg:\n\n[ 0.903172] BUG: kernel NULL pointer dereference, address: 0000000000000000\n[ 0.903571] #PF: supervisor write access in kernel mode\n[ 0.903860] #PF: error_code(0x0002) - not-present page\n[ 0.904177] PGD 10299b067 P4D 10299b067 PUD 10299c067 PMD 0\n[ 0.904502] Oops: Oops: 0002 [#1] SMP NOPTI\n[ 0.904737] CPU: 0 UID: 0 PID: 135 Comm: exploit Not tainted 6.19.0-rc3+ #2 NONE\n[ 0.905157] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014\n[ 0.905754] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2))\n[ 0.906046] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0\n\nCode starting with the faulting instruction\n===========================================\n 0:\t0f 84 4d 01 00 00 \tje 0x153\n 6:\t48 89 70 18 \tmov %rsi,0x18(%rax)\n a:\t8b 4b 10 \tmov 0x10(%rbx),%ecx\n d:\t48 c7 c2 ff ff ff ff \tmov $0xffffffffffffffff,%rdx\n 14:\t48 8b 78 08 \tmov 0x8(%rax),%rdi\n 18:\t48 d3 e2 \tshl %cl,%rdx\n 1b:\t48 21 f2 \tand %rsi,%rdx\n 1e:\t48 2b 13 \tsub (%rbx),%rdx\n 21:\t48 8b 30 \tmov (%rax),%rsi\n 24:\t48 d3 ea \tshr %cl,%rdx\n 27:\t8b 4b 18 \tmov 0x18(%rbx),%ecx\n\t...\n[ 0.907095] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246\n[ 0.907368] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000\n[ 0.907723] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000\n[ 0.908100] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000\n[ 0.908451] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000\n[ 0.908804] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880\n[ 0.909179] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000\n[ 0.909572] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 0.909857] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0\n[ 0.910247] PKRU: 55555554\n[ 0.910391] Call Trace:\n[ 0.910527] \u003cTASK\u003e\n[ 0.910638] qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1485)\n[ 0.910826] qdisc_reset (include/linux/skbuff.h:2195 include/linux/skbuff.h:2501 include/linux/skbuff.h:3424 include/linux/skbuff.h:3430 net/sched/sch_generic.c:1036)\n[ 0.911040] __qdisc_destroy (net/sched/sch_generic.c:1076)\n[ 0.911236] tc_new_tfilter (net/sched/cls_api.c:2447)\n[ 0.911447] rtnetlink_rcv_msg (net/core/rtnetlink.c:6958)\n[ 0.911663] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6861)\n[ 0.911894] netlink_rcv_skb (net/netlink/af_netlink.c:2550)\n[ 0.912100] netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)\n[ 0.912296] ? __alloc_skb (net/core/skbuff.c:706)\n[ 0.912484] netlink_sendmsg (net/netlink/af\n---truncated---"
}
],
"providerMetadata": {
"dateUpdated": "2026-05-11T21:57:35.535Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/6116a83ec167d3ab1390cded854d237481f41b63"
},
{
"url": "https://git.kernel.org/stable/c/0809c4bc06c9c961222df29f2eccfd449304056f"
},
{
"url": "https://git.kernel.org/stable/c/cdb24200b043438a144df501f1ebbd926bb1a2c7"
},
{
"url": "https://git.kernel.org/stable/c/11bf9134613f6c71fc0ff36c5d8d33856f6ae3bb"
},
{
"url": "https://git.kernel.org/stable/c/43497313d0da3e12b5cfcd97aa17bf48ee663f95"
},
{
"url": "https://git.kernel.org/stable/c/51ffd447bc37bf1a5776b85523f51d2bc69977f6"
},
{
"url": "https://git.kernel.org/stable/c/c1d73b1480235731e35c81df70b08f4714a7d095"
}
],
"title": "net/sched: sch_qfq: Fix NULL deref when deactivating inactive aggregate in qfq_reset",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-22976",
"datePublished": "2026-01-21T06:57:23.939Z",
"dateReserved": "2026-01-13T15:37:45.935Z",
"dateUpdated": "2026-10-19T18:25:25.738Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
Loading timeline…
Loading…
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.