linux — security advisory
In the Linux kernel, the following vulnerability has been resolved: net/sched: accept TCA_STAB only for root qdisc Most qdiscs maintain their backlog using qdisc_pkt_len(skb) on the assumption it is invariant between the enqueue() and dequeue() handlers. Unfortunately syzbot can crash a host rather easily using a TBF + SFQ combination, with an STAB on SFQ [1] We can't support TCA_STAB on arbitrary level, this would require to maintain per-qdisc storage. [1] [ 88.796496] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 88.798611] #PF: supervisor read access in kernel mode [ 88.799014] #PF: error_code(0x0000) - not-present page [ 88.799506] PGD 0 P4D 0 [ 88.799829] Oops: Oops: 0000 [#1] SMP NOPTI [ 88.800569] CPU: 14 UID: 0 PID: 2053 Comm: b371744477 Not tainted 6.12.0-rc1-virtme #1117 [ 88.801107] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 88.801779] RIP: 0010:sfq_dequeue (net/sched/sch_sfq.c:272 net/sched/sch_sfq.c:499) sch_sfq [ 88.802544] Code: 0f b7 50 12 48 8d 04 d5 00 00 00 00 48 89 d6 48 29 d0 48 8b 91 c0 01 00 00 48 c1 e0 03 48 01 c2 66 83 7a 1a 00 7e c0 48 8b 3a <4c> 8b 07 4c 89 02 49 89 50 08 48 c7 47 08 00 00 00 00 48 c7 07 00 All code ======== 0: 0f b7 50 12 movzwl 0x12(%rax),%edx 4: 48 8d 04 d5 00 00 00 lea 0x0(,%rdx,8),%rax b: 00 c: 48 89 d6 mov %rdx,%rsi f: 48 29 d0 sub %rdx,%rax 12: 48 8b 91 c0 01 00 00 mov 0x1c0(%rcx),%rdx 19: 48 c1 e0 03 shl $0x3,%rax 1d: 48 01 c2 add %rax,%rdx 20: 66 83 7a
- Products
- linux
- Affected versions
- 6.1.106-1, 6.1.106-2, 6.1.106-3, 6.1.112-1, 6.1.27-1, 6.1.37-1, 6.1.38-1, 6.1.38-2, 6.1.38-2~bpo11+1, 6.1.38-3, 6.1.38-4, 6.1.38-4~bpo11+1, 6.1.52-1, 6.1.55-1, 6.1.55-1~bpo11+1, 6.1.64-1, 6.1.66-1, 6.1.67-1, 6.1.69-1, 6.1.69-1~bpo11+1, 6.1.76-1, 6.1.76-1~bpo11+1, 6.1.82-1, 6.1.85-1, 6.1.90-1, 6.1.90-1~bpo11+1, 6.1.94-1, 6.1.94-1~bpo11+1, 6.1.98-1, 6.1.99-1
- Fixed versions
- 6.1.115-1, 6.11.4-1
- CVEs
- CVE-2024-50039
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 30 Oct 2026, 16:19 UTC · Revision 1
Source evidence
In the Linux kernel, the following vulnerability has been resolved: net/sched: accept TCA_STAB only for root qdisc Most qdiscs maintain their backlog using qdisc_pkt_len(skb) on the assumption it is invariant between the enqueue() and dequeue() handlers. Unfortunately syzbot can crash a host rather easily using a TBF + SFQ combination, with an STAB on SFQ [1] We can't support TCA_STAB on arbitrary level, this would require to maintain per-qdisc storage. [1] [ 88.796496] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 88.798611] #PF: supervisor read access in kernel mode [ 88.799014] #PF: error_code(0x0000) - not-present page [ 88.799506] PGD 0 P4D 0 [ 88.799829] Oops: Oops: 0000 [#1] SMP NOPTI [ 88.800569] CPU: 14 UID: 0 PID: 2053 Comm: b371744477 Not tainted 6.12.0-rc1-virtme #1117 [ 88.801107] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 88.801779] RIP: 0010:sfq_dequeue (net/sched/sch_sfq.c:272 net/sched/sch_sfq.c:499) sch_sfq [ 88.802544] Code: 0f b7 50 12 48 8d 04 d5 00 00 00 00 48 89 d6 48 29 d0 48 8b 91 c0 01 00 00 48 c1 e0 03 48 01 c2 66 83 7a 1a 00 7e c0 48 8b 3a <4c> 8b 07 4c 89 02 49 89 50 08 48 c7 47 08 00 00 00 00 48 c7 07 00 All code ======== 0: 0f b7 50 12 movzwl 0x12(%rax),%edx 4: 48 8d 04 d5 00 00 00 lea 0x0(,%rdx,8),%rax b: 00 c: 48 89 d6 mov %rdx,%rsi f: 48 29 d0 sub %rdx,%rax 12: 48 8b 91 c0 01 00 00 mov 0x1c0(%rcx),%rdx 19: 48 c1 e0 03 shl $0x3,%rax 1d: 48 01 c2 add %rax,%rdx 20: 66 83 7a
osv:DEBIAN-CVE-2024-50039
linux
Fixed versions: 6.1.115-1
linux
Fixed versions: 6.11.4-1
linux
Fixed versions: 6.11.4-1
Complete source record
{
"id": "ee448788f427c04686ccfd2cd9d95fc5d59f10cfc80cdc2b414536867d00b9ee",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2024-50039",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2024-50039",
"summary": "In the Linux kernel, the following vulnerability has been resolved: net/sched: accept TCA_STAB only for root qdisc Most qdiscs maintain their backlog using qdisc_pkt_len(skb) on the assumption it is invariant between the enqueue() and dequeue() handlers. Unfortunately syzbot can crash a host rather easily using a TBF + SFQ combination, with an STAB on SFQ [1] We can't support TCA_STAB on arbitrary level, this would require to maintain per-qdisc storage. [1] [ 88.796496] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 88.798611] #PF: supervisor read access in kernel mode [ 88.799014] #PF: error_code(0x0000) - not-present page [ 88.799506] PGD 0 P4D 0 [ 88.799829] Oops: Oops: 0000 [#1] SMP NOPTI [ 88.800569] CPU: 14 UID: 0 PID: 2053 Comm: b371744477 Not tainted 6.12.0-rc1-virtme #1117 [ 88.801107] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 88.801779] RIP: 0010:sfq_dequeue (net/sched/sch_sfq.c:272 net/sched/sch_sfq.c:499) sch_sfq [ 88.802544] Code: 0f b7 50 12 48 8d 04 d5 00 00 00 00 48 89 d6 48 29 d0 48 8b 91 c0 01 00 00 48 c1 e0 03 48 01 c2 66 83 7a 1a 00 7e c0 48 8b 3a <4c> 8b 07 4c 89 02 49 89 50 08 48 c7 47 08 00 00 00 00 48 c7 07 00 All code ======== 0: 0f b7 50 12 movzwl 0x12(%rax),%edx 4: 48 8d 04 d5 00 00 00 lea 0x0(,%rdx,8),%rax b: 00 c: 48 89 d6 mov %rdx,%rsi f: 48 29 d0 sub %rdx,%rax 12: 48 8b 91 c0 01 00 00 mov 0x1c0(%rcx),%rdx 19: 48 c1 e0 03 shl $0x3,%rax 1d: 48 01 c2 add %rax,%rdx 20: 66 83 7a",
"evidence": "osv:DEBIAN-CVE-2024-50039",
"products": [
{
"name": {
"value": "linux",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.1.115-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "6.1.106-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.106-2",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.106-3",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.112-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.27-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.37-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.38-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.38-2",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.38-2~bpo11+1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.38-3",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.38-4",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.38-4~bpo11+1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.52-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.55-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.55-1~bpo11+1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.64-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.66-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.67-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.69-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.69-1~bpo11+1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.76-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.76-1~bpo11+1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.82-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.85-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.90-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.90-1~bpo11+1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.94-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.94-1~bpo11+1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.98-1",
"evidence": "/affected/0/versions"
},
{
"value": "6.1.99-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "linux",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.11.4-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "linux",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.11.4-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2024-50039",
"aliases": [
"DEBIAN-CVE-2024-50039"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "6.1.115-1"
}
]
}
],
"package": {
"name": "linux",
"purl": "pkg:deb/debian/linux?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"6.1.106-1",
"6.1.106-2",
"6.1.106-3",
"6.1.112-1",
"6.1.27-1",
"6.1.37-1",
"6.1.38-1",
"6.1.38-2",
"6.1.38-2~bpo11+1",
"6.1.38-3",
"6.1.38-4",
"6.1.38-4~bpo11+1",
"6.1.52-1",
"6.1.55-1",
"6.1.55-1~bpo11+1",
"6.1.64-1",
"6.1.66-1",
"6.1.67-1",
"6.1.69-1",
"6.1.69-1~bpo11+1",
"6.1.76-1",
"6.1.76-1~bpo11+1",
"6.1.82-1",
"6.1.85-1",
"6.1.90-1",
"6.1.90-1~bpo11+1",
"6.1.94-1",
"6.1.94-1~bpo11+1",
"6.1.98-1",
"6.1.99-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2024-50039.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "6.11.4-1"
}
]
}
],
"package": {
"name": "linux",
"purl": "pkg:deb/debian/linux?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2024-50039.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "6.11.4-1"
}
]
}
],
"package": {
"name": "linux",
"purl": "pkg:deb/debian/linux?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2024-50039.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-15T09:47:29.178453880Z",
"provider": "osv",
"upstream": [
"CVE-2024-50039"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2024-50039"
]
},
"related_cves": [
{
"value": "CVE-2024-50039",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 327472,
"published_at": "2024-10-21T20:15:16.957+00:00"
}