net/tls: avoid potential deadlock in tls_set_device_offload_rx()

If device supports offload, but offload fails tls_set_device_offload_rx()
will call tls_sw_free_resources_rx() which (unhelpfully) releases
and reacquires the socket lock.

For a small fix release and reacquire the device_offload_lock.

Fixes: 4799ac8 ("tls: Add rx inline crypto offload")
Signed-off-by: Jakub Kicinski <[email protected]>
Reviewed-by: Dirk van der Merwe <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Jakub Kicinski

net/tls/tls_device.c

@@ -904,7 +904,9 @@ int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
 	goto release_netdev;
 
 free_sw_resources:
+	up_read(&device_offload_lock);
 	tls_sw_free_resources_rx(sk);
+	down_read(&device_offload_lock);
 release_ctx:
 	ctx->priv_ctx_rx = NULL;
 release_netdev: