CVE-2024-35895

Published at:
2024-05-19T09:15:10.477
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Global infos:

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); 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.

CVE Status: Analyzed

References:

  • 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  • 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  • 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  • 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  • 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  • 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  • 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  • af854a3a-2127-422b-91ae-364da2661108
  • af854a3a-2127-422b-91ae-364da2661108
  • af854a3a-2127-422b-91ae-364da2661108
  • af854a3a-2127-422b-91ae-364da2661108
  • af854a3a-2127-422b-91ae-364da2661108
  • af854a3a-2127-422b-91ae-364da2661108
  • af854a3a-2127-422b-91ae-364da2661108
  • af854a3a-2127-422b-91ae-364da2661108
  • Metrics:

    AttributeValue
    Attack ComplexityLOW
    Attack VectorLOCAL
    Availability ImpactHIGH
    Base Score5.5
    Base SeverityMEDIUM
    Confidentiality ImpactNONE
    Integrity ImpactNONE
    Privileges RequiredLOW
    ScopeUNCHANGED
    User InteractionNONE
    Vector StringCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    Exploitability Score1.8
    Impact Score3.6
    Source[email protected]
    TypePrimary

    Links:

    Exploit-db
    Github