[PATCH net] net/tls: avoid potential deadlock in tls_set_device_offload_rx()

[Jakub Kicinski]

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: 4799ac81e52a ("tls: Add rx inline crypto offload")
Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vanderme...@netronome.com>
---
 net/tls/tls_device.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index 9f3bdbc1e593..1b5f55cac613 100644
--- a/net/tls/tls_device.c
+++ b/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:
-- 
2.21.0