CVE-2021-47132

Summary

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

mptcp: fix sk_forward_memory corruption on retransmission

MPTCP sk_forward_memory handling is a bit special, as such field is protected by the msk socket spin_lock, instead of the plain socket lock.

Currently we have a code path updating such field without handling the relevant lock:

__mptcp_retrans() -> __mptcp_clean_una_wakeup()

Several helpers in __mptcp_clean_una_wakeup() will update sk_forward_alloc, possibly causing such field corruption, as reported by Matthieu.

Address the issue providing and using a new variant of blamed function which explicitly acquires the msk spin lock.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux64b9cea7a0afe579dd2682f1f1c04f2e4e72fd25 < b9c78b1a95966a7bd2ddae05b73eafc0cda4fba3affected
LinuxLinux64b9cea7a0afe579dd2682f1f1c04f2e4e72fd25 < b5941f066b4ca331db225a976dae1d6ca8cf0ae3affected
LinuxLinux96db8ffef07516a6d7414b6988f2a4298a839977affected
LinuxLinux5.11.4 < 5.12affected
LinuxLinux5.12affected
LinuxLinux0 < 5.12unaffected
LinuxLinux5.12.10 <= 5.12.*unaffected
LinuxLinux5.13 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

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

CVE Program Container

Additional References

References