CVE-2024-35895

Source
https://nvd.nist.gov/vuln/detail/CVE-2024-35895
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-35895.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2024-35895
Downstream
Related
Published
2024-05-19T09:15:10Z
Modified
2025-08-09T19:01:27Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
[none]
Details

In the Linux kernel, the following vulnerability has been resolved:

bpf, sockmap: Prevent lock inversion deadlock in map delete elem

syzkaller started using corpuses where a BPF tracing program deletes elements from a sockmap/sockhash map. Because BPF tracing programs can be invoked from any interrupt context, locks taken during a mapdeleteelem operation must be hardirq-safe. Otherwise a deadlock due to lock inversion is possible, as reported by lockdep:

   CPU0                    CPU1
   ----                    ----

lock(&htab->buckets[i].lock); localirqdisable(); lock(&host->lock); lock(&htab->buckets[i].lock); <Interrupt> lock(&host->lock);

Locks in sockmap are hardirq-unsafe by design. We expects elements to be deleted from sockmap/sockhash only in task (normal) context with interrupts enabled, or in softirq context.

Detect when mapdeleteelem operation is invoked from a context which is not hardirq-unsafe, that is interrupts are disabled, and bail out with an error.

Note that map updates are not affected by this issue. BPF verifier does not allow updating sockmap/sockhash from a BPF tracing program today.

References

Affected packages