net/sched: accept TCA_STAB only for root qdisc
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
CVE-2024-50039
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-2024-50039
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": "175f9c1bba9b825d22b142d183c9e175488b260c",
"lessThan": "2acbb9539bc2284e30d2aeb789c3d96287014264",
"versionType": "git"
},
{
"status": "affected",
"version": "175f9c1bba9b825d22b142d183c9e175488b260c",
"lessThan": "adbc3eef43fc94c7c8436da832691ae02333a972",
"versionType": "git"
},
{
"status": "affected",
"version": "175f9c1bba9b825d22b142d183c9e175488b260c",
"lessThan": "8fb6503592d39065316f45d267c5527b4e7cd995",
"versionType": "git"
},
{
"status": "affected",
"version": "175f9c1bba9b825d22b142d183c9e175488b260c",
"lessThan": "76feedc74b90270390fbfdf74a2e944e96872363",
"versionType": "git"
},
{
"status": "affected",
"version": "175f9c1bba9b825d22b142d183c9e175488b260c",
"lessThan": "1edf039ee01788ffc25625fe58a903ae2efa213e",
"versionType": "git"
},
{
"status": "affected",
"version": "175f9c1bba9b825d22b142d183c9e175488b260c",
"lessThan": "3dc6ee96473cc2962c6db4297d4631f261be150f",
"versionType": "git"
},
{
"status": "affected",
"version": "175f9c1bba9b825d22b142d183c9e175488b260c",
"lessThan": "3cb7cf1540ddff5473d6baeb530228d19bc97b8a",
"versionType": "git"
}
],
"programFiles": [
"include/net/sch_generic.h",
"net/sched/sch_api.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.27"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.27",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.4.285",
"versionType": "semver",
"lessThanOrEqual": "5.4.*"
},
{
"status": "unaffected",
"version": "5.10.227",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.168",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.113",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.57",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.11.4",
"versionType": "semver",
"lessThanOrEqual": "6.11.*"
},
{
"status": "unaffected",
"version": "6.12",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/net/sch_generic.h",
"net/sched/sch_api.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2024-50039
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #26776 · Revision 1
- Added to Heist Feed
- Publisher date