CVE-2022-49669

Summary

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

mptcp: fix race on unaccepted mptcp sockets

When the listener socket owning the relevant request is closed, it frees the unaccepted subflows and that causes later deletion of the paired MPTCP sockets.

The mptcp socket's worker can run in the time interval between such delete operations. When that happens, any access to msk->first will cause an UaF access, as the subflow cleanup did not cleared such field in the mptcp socket.

Address the issue explicitly traversing the listener socket accept queue at close time and performing the needed cleanup on the pending msk.

Note that the locking is a bit tricky, as we need to acquire the msk socket lock, while still owning the subflow socket one.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux86e39e04482b0aadf3ee3ed5fcf2d63816559d36 < a8a3e95c74e48c2c9b07b81fafda9122993f2e12affected
LinuxLinux86e39e04482b0aadf3ee3ed5fcf2d63816559d36 < 6aeed9045071f2252ff4e98fc13d1e304f33e5b0affected
LinuxLinux5.17affected
LinuxLinux0 < 5.17unaffected
LinuxLinux5.18.10 <= 5.18.*unaffected
LinuxLinux5.19 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

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

References