bpf: Fix effective prog array index with BPF_F_PREORDER
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.6.145, 6.12.97, 6.15, 6.18.40, 7.1.5
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
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.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- Linux Linux
From bc8023ef3b11410682e5d4990e05e5bc2d3e1c94 · fixed in 525e408c27ae714e538b8c608c3a974df3ab6c92; From 555c0b713ca83968d3c843cb15485b9ba3367b1b · fixed in 41b4320b84fdafe1ab586b06453d30d50415db59; From 4b82b181a26cff8bf7adc3a85a88d121d92edeaf · fixed in 9697db03e010391c55ae75192cbdf30c5a72c114; From 4b82b181a26cff8bf7adc3a85a88d121d92edeaf · fixed in b584f107ab90222bd825dcb4c5977326ff684109; From 4b82b181a26cff8bf7adc3a85a88d121d92edeaf · fixed in f08aaee3152d0dfc578b3f2586932d82062701dd; From 6.6.93 · fixed in 6.6.145; From 6.12.31 · fixed in 6.12.97; From 6.14.9 · fixed in 6.15
- Linux Linux
6.15
- KernelLinux
fixed in 6.6.145; From 6.7.0 · fixed in 6.12.97; From 6.13.0 · fixed in 6.18.40; From 6.15.0 · fixed in 7.1.5