[SRU][F][PATCH 0/1] CVE-2021-47001

[Jacob Martin]

[Impact]

A race condition exists in the RPC over RDMA driver where after a reconnect,
the congestion window is increased before enough receive work requests are
posted to receive the replies. This results in an immediate receive-not-ready
response, causing the new connection to be lost.

[Fix]

This issue is resolved by 35d8b10a2588 ("xprtrdma: Fix cwnd update ordering").
This fix posts more receive work requests before adjusting the congestion
window, so enough are available to handle the new requests.

Noble: Not affected
Jammy: Not affected
Focal: Backport from mainline with trivial context adjustments for K5.4.
Bionic: Not affected
Xenial: Not affected
Trusty: Not affected

[Test Case]

Compile tested.

[Where problems could occur]

An issue with this fix would result in misbehavior of the rpcrdma driver.

Chuck Lever (1):
  xprtrdma: Fix cwnd update ordering

 net/sunrpc/xprtrdma/rpc_rdma.c  |  3 ++-
 net/sunrpc/xprtrdma/verbs.c     | 10 +++++-----
 net/sunrpc/xprtrdma/xprt_rdma.h |  2 +-
 3 files changed, 8 insertions(+), 7 deletions(-)

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2.43.0