6.6-stable review patch. If anyone has any objections, please let me know.
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From: Benjamin Coddington bcodding@redhat.com
[ Upstream commit d7bdd849ef1b681da03ac05ca0957b2cbe2d24b6 ]
We've noticed a situation where an unstable TCP connection can cause the TLS handshake to timeout waiting for userspace to complete it. When this happens, we don't want to return from xs_tls_handshake_sync() with zero, as this will cause the upper xprt to be set CONNECTED, and subsequent attempts to transmit will be returned with -EPIPE. The sunrpc machine does not recover from this situation and will spin attempting to transmit.
The return value of tls_handshake_cancel() can be used to detect a race with completion:
* tls_handshake_cancel - cancel a pending handshake * Return values: * %true - Uncompleted handshake request was canceled * %false - Handshake request already completed or not found
If true, we do not want the upper xprt to be connected, so return -ETIMEDOUT. If false, its possible the handshake request was lost and that may be the reason for our timeout. Again we do not want the upper xprt to be connected, so return -ETIMEDOUT.
Ensure that we alway return an error from xs_tls_handshake_sync() if we call tls_handshake_cancel().
Signed-off-by: Benjamin Coddington bcodding@redhat.com Reviewed-by: Chuck Lever chuck.lever@oracle.com Fixes: 75eb6af7acdf ("SUNRPC: Add a TCP-with-TLS RPC transport class") Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/sunrpc/xprtsock.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 714da627fba8e..c528297245125 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2596,11 +2596,10 @@ static int xs_tls_handshake_sync(struct rpc_xprt *lower_xprt, struct xprtsec_par rc = wait_for_completion_interruptible_timeout(&lower_transport->handshake_done, XS_TLS_HANDSHAKE_TO); if (rc <= 0) { - if (!tls_handshake_cancel(sk)) { - if (rc == 0) - rc = -ETIMEDOUT; - goto out_put_xprt; - } + tls_handshake_cancel(sk); + if (rc == 0) + rc = -ETIMEDOUT; + goto out_put_xprt; }
rc = lower_transport->xprt_err;