6.6-stable review patch. If anyone has any objections, please let me know.
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From: David Howells dhowells@redhat.com
[ Upstream commit fc9de52de38f656399d2ce40f7349a6b5f86e787 ]
If a call gets aborted (e.g. because kafs saw a signal) between it being queued for connection and the I/O thread picking up the call, the abort will be prioritised over the connection and it will be removed from local->new_client_calls by rxrpc_disconnect_client_call() without a lock being held. This may cause other calls on the list to disappear if a race occurs.
Fix this by taking the client_call_lock when removing a call from whatever list its ->wait_link happens to be on.
Signed-off-by: David Howells dhowells@redhat.com cc: linux-afs@lists.infradead.org Reported-by: Marc Dionne marc.dionne@auristor.com Fixes: 9d35d880e0e4 ("rxrpc: Move client call connection to the I/O thread") Link: https://patch.msgid.link/726660.1730898202@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/trace/events/rxrpc.h | 1 + net/rxrpc/conn_client.c | 4 ++++ 2 files changed, 5 insertions(+)
diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h index 3322fb93a260b..ed36f5f577a9d 100644 --- a/include/trace/events/rxrpc.h +++ b/include/trace/events/rxrpc.h @@ -283,6 +283,7 @@ EM(rxrpc_call_see_input, "SEE input ") \ EM(rxrpc_call_see_release, "SEE release ") \ EM(rxrpc_call_see_userid_exists, "SEE u-exists") \ + EM(rxrpc_call_see_waiting_call, "SEE q-conn ") \ E_(rxrpc_call_see_zap, "SEE zap ")
#define rxrpc_txqueue_traces \ diff --git a/net/rxrpc/conn_client.c b/net/rxrpc/conn_client.c index 1d95f8bc769fa..a0231b64fb6ef 100644 --- a/net/rxrpc/conn_client.c +++ b/net/rxrpc/conn_client.c @@ -507,6 +507,7 @@ void rxrpc_connect_client_calls(struct rxrpc_local *local)
spin_lock(&local->client_call_lock); list_move_tail(&call->wait_link, &bundle->waiting_calls); + rxrpc_see_call(call, rxrpc_call_see_waiting_call); spin_unlock(&local->client_call_lock);
if (rxrpc_bundle_has_space(bundle)) @@ -577,7 +578,10 @@ void rxrpc_disconnect_client_call(struct rxrpc_bundle *bundle, struct rxrpc_call _debug("call is waiting"); ASSERTCMP(call->call_id, ==, 0); ASSERT(!test_bit(RXRPC_CALL_EXPOSED, &call->flags)); + /* May still be on ->new_client_calls. */ + spin_lock(&local->client_call_lock); list_del_init(&call->wait_link); + spin_unlock(&local->client_call_lock); return; }