[PATCH 5.4 24/33] rxrpc: Call state should be read with READ_ONCE() under some circumstances
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-01-22 15:02:32
Also in:
lkml
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-01-22 15:02:32
Also in:
lkml
From: Baptiste Lepers <redacted>
[ Upstream commit a95d25dd7b94a5ba18246da09b4218f132fed60e ]
The call state may be changed at any time by the data-ready routine in
response to received packets, so if the call state is to be read and acted
upon several times in a function, READ_ONCE() must be used unless the call
state lock is held.
As it happens, we used READ_ONCE() to read the state a few lines above the
unmarked read in rxrpc_input_data(), so use that value rather than
re-reading it.
Fixes: a158bdd3247b ("rxrpc: Fix call timeouts")
Signed-off-by: Baptiste Lepers <redacted>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/161046715522.2450566.488819910256264150.stgit@warthog.procyon.org.uk (local)
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/rxrpc/input.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c@@ -431,7 +431,7 @@ static void rxrpc_input_data(struct rxrp return; } - if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST) { + if (state == RXRPC_CALL_SERVER_RECV_REQUEST) { unsigned long timo = READ_ONCE(call->next_req_timo); unsigned long now, expect_req_by;