bpf: Fix effective prog array index with BPF_F_PREORDER
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix effective prog array index with BPF_F_PREORDER replace_effective_prog() and purge_effective_progs() located the slot in the effective array by walking the program hlist and counting entries linearly. That count does not match the array layout: compute_effective_ progs() places BPF_F_PREORDER programs at the front (ancestor cgroup first, attach order within a cgroup) and the rest after them (descendant cgroup first). So when a preorder program is present, the linear hlist position no longer equals the program's index in the effective array. For replace_effective_prog() (bpf_link_update()) this overwrote the wrong slot, corrupting the effective order. For purge_effective_progs(), it could dummy out a slot belonging to a different program and leave the detached program in the array while bpf_prog_put() drops its reference, i.e. a use-after-free. Fix both by replaying compute_effective_progs()'s placement (including the per-cgroup preorder reversal) in a shared effective_prog_pos() helper. Identify the entry by its struct bpf_prog_list pointer rather than by (prog, link) value, so the lookup resolves to exactly the attachment the syscall selected even when the same bpf_prog is attached to several cgroups in the hierarchy.
CVE-2026-72427
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-2026-72427
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": "bc8023ef3b11410682e5d4990e05e5bc2d3e1c94",
"lessThan": "525e408c27ae714e538b8c608c3a974df3ab6c92",
"versionType": "git"
},
{
"status": "affected",
"version": "555c0b713ca83968d3c843cb15485b9ba3367b1b",
"lessThan": "41b4320b84fdafe1ab586b06453d30d50415db59",
"versionType": "git"
},
{
"status": "affected",
"version": "4b82b181a26cff8bf7adc3a85a88d121d92edeaf",
"lessThan": "9697db03e010391c55ae75192cbdf30c5a72c114",
"versionType": "git"
},
{
"status": "affected",
"version": "4b82b181a26cff8bf7adc3a85a88d121d92edeaf",
"lessThan": "b584f107ab90222bd825dcb4c5977326ff684109",
"versionType": "git"
},
{
"status": "affected",
"version": "4b82b181a26cff8bf7adc3a85a88d121d92edeaf",
"lessThan": "f08aaee3152d0dfc578b3f2586932d82062701dd",
"versionType": "git"
},
{
"status": "affected",
"version": "4707ad649cf662add3058bff47430817811b048d",
"versionType": "git"
},
{
"status": "affected",
"version": "6.6.93",
"lessThan": "6.6.145",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.12.31",
"lessThan": "6.12.97",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.14.9",
"lessThan": "6.15",
"versionType": "semver"
}
],
"programFiles": [
"kernel/bpf/cgroup.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": "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": [
"kernel/bpf/cgroup.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-72427
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #33051 · Revision 1
- Added to Heist Feed
- Publisher date