bpf: Fix oob access in cgroup local storage
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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 5.15.192, 6.1.151, 6.6.105, 6.12.46, 6.16.1
- 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 oob access in cgroup local storage Lonial reported that an out-of-bounds access in cgroup local storage can be crafted via tail calls. Given two programs each utilizing a cgroup local storage with a different value size, and one program doing a tail call into the other. The verifier will validate each of the indivial programs just fine. However, in the runtime context the bpf_cg_run_ctx holds an bpf_prog_array_item which contains the BPF program as well as any cgroup local storage flavor the program uses. Helpers such as bpf_get_local_storage() pick this up from the runtime context: ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx); storage = ctx->prog_item->cgroup_storage[stype]; if (stype == BPF_CGROUP_STORAGE_SHARED) ptr = &READ_ONCE(storage->buf)->data[0]; else ptr = this_cpu_ptr(storage->percpu_buf); For the second program which was called from the originally attached one, this means bpf_get_local_storage() will pick up the former program's map, not its own. With mismatching sizes, this can result in an unintended out-of-bounds access. To fix this issue, we need to extend bpf_map_owner with an array of storage_cookie[] to match on i) the exact maps from the original program if the second program was using bpf_get_local_storage(), or ii) allow the tail call combination if the second program was not using any of the cgroup local storage maps.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- Linux Linux
From 7d9c3427894fe70d1347b4820476bf37736d2ff0 · fixed in c1c74584b9b4043c52e41fec415226e582d266a3; From 7d9c3427894fe70d1347b4820476bf37736d2ff0 · fixed in 66da7cee78590259b400e51a70622ccd41da7bb2; From 7d9c3427894fe70d1347b4820476bf37736d2ff0 · fixed in 7acfa07c585e3d7a64654d38f0a5c762877d0b9b; From 7d9c3427894fe70d1347b4820476bf37736d2ff0 · fixed in 41688d1fc5d163a6c2c0e95c0419e2cb31a44648; From 7d9c3427894fe70d1347b4820476bf37736d2ff0 · fixed in 19341d5c59e8c7e8528e40f8663e99d67810473c; From 7d9c3427894fe70d1347b4820476bf37736d2ff0 · fixed in abad3d0bad72a52137e0c350c59542d75ae4f513
- Linux Linux
5.9
- KernelLinux
From 5.9.0 · fixed in 5.15.192; From 5.16.0 · fixed in 6.1.151; From 6.2.0 · fixed in 6.6.105; From 6.7.0 · fixed in 6.12.46; From 6.13.0 · fixed in 6.16.1