CVE-2021-47001

Summary

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

xprtrdma: Fix cwnd update ordering

After a reconnect, the reply handler is opening the cwnd (and thus enabling more RPC Calls to be sent) /before/ rpcrdma_post_recvs() can post enough Receive WRs to receive their replies. This causes an RNR and the new connection is lost immediately.

The race is most clearly exposed when KASAN and disconnect injection are enabled. This slows down rpcrdma_rep_create() enough to allow the send side to post a bunch of RPC Calls before the Receive completion handler can invoke ib_post_recv().

Affected Software

VendorProductVersion RangeStatus
LinuxLinux2ae50ad68cd79224198b525f7bd645c9da98b6ff < eddae8be7944096419c2ae29477a45f767d0fcd4affected
LinuxLinux2ae50ad68cd79224198b525f7bd645c9da98b6ff < 8834ecb5df22b7ff3c9b0deba7726579bb613f95affected
LinuxLinux2ae50ad68cd79224198b525f7bd645c9da98b6ff < 19b5fa9489b5706bc878c3a522a7f771079e2fa0affected
LinuxLinux2ae50ad68cd79224198b525f7bd645c9da98b6ff < 35d8b10a25884050bb3b0149b62c3818ec59f77caffected
LinuxLinux3791c5982ba1eebf2900ee7ca7b9a89619c26d54affected
LinuxLinux5.4.13 < 5.5affected
LinuxLinux5.5affected
LinuxLinux0 < 5.5unaffected
LinuxLinux5.10.38 <= 5.10.*unaffected
LinuxLinux5.11.22 <= 5.11.*unaffected
LinuxLinux5.12.5 <= 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