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CVE-2024-35895

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

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.4.274, 5.10.215, 5.15.154, 6.1.85, 6.6.26, and 1 more
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: partial

Summary

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 map_delete_elem 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); local_irq_disable(); 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 map_delete_elem 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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • Linux Linux

    From 604326b41a6fb9b4a78b6179335decee0365cd8c · fixed in f7990498b05ac41f7d6a190dc0418ef1d21bf058; From 604326b41a6fb9b4a78b6179335decee0365cd8c · fixed in dd54b48db0c822ae7b520bc80751f0a0a173ef75; From 604326b41a6fb9b4a78b6179335decee0365cd8c · fixed in d1e73fb19a4c872d7a399ad3c66e8ca30e0875ec; From 604326b41a6fb9b4a78b6179335decee0365cd8c · fixed in a44770fed86515eedb5a7c00b787f847ebb134a5; From 604326b41a6fb9b4a78b6179335decee0365cd8c · fixed in 668b3074aa14829e2ac2759799537a93b60fef86; From 604326b41a6fb9b4a78b6179335decee0365cd8c · fixed in 6af057ccdd8e7619960aca1f0428339f213b31cd; From 604326b41a6fb9b4a78b6179335decee0365cd8c · fixed in ff91059932401894e6c86341915615c5eb0eca48

  • Linux Linux

    4.20

  • KernelLinux

    From 4.20.0 · fixed in 5.4.274; From 5.5.0 · fixed in 5.10.215; From 5.11.0 · fixed in 5.15.154; From 5.16.0 · fixed in 6.1.85; From 6.2.0 · fixed in 6.6.26; From 6.7.0 · fixed in 6.8.5

References 7

git.kernel.org