CVE-2024-26740

Summary

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

net/sched: act_mirred: use the backlog for mirred ingress

The test Davide added in commit ca22da2fbd69 ("act_mirred: use the backlog for nested calls to mirred ingress") hangs our testing VMs every 10 or so runs, with the familiar tcp_v4_rcv -> tcp_v4_rcv deadlock reported by lockdep.

The problem as previously described by Davide (see Link) is that if we reverse flow of traffic with the redirect (egress -> ingress) we may reach the same socket which generated the packet. And we may still be holding its socket lock. The common solution to such deadlocks is to put the packet in the Rx backlog, rather than run the Rx path inline. Do that for all egress -> ingress reversals, not just once we started to nest mirred calls.

In the past there was a concern that the backlog indirection will lead to loss of error reporting / less accurate stats. But the current workaround does not seem to address the issue.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux53592b3640019f2834701093e38272fdfd367ad8 < 7c787888d164689da8b1b115f3ef562c1e843af4affected
LinuxLinux53592b3640019f2834701093e38272fdfd367ad8 < 60ddea1600bc476e0f5e02bce0e29a460ccbf0beaffected
LinuxLinux53592b3640019f2834701093e38272fdfd367ad8 < 52f671db18823089a02f07efc04efdb2272ddc17affected
LinuxLinux4.10affected
LinuxLinux0 < 4.10unaffected
LinuxLinux6.6.19 <= 6.6.*unaffected
LinuxLinux6.7.7 <= 6.7.*unaffected
LinuxLinux6.8 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References