[PATCH net] net/tls: don't leak IV and record seq when offload fails

[Jakub Kicinski]

When device refuses the offload in tls_set_device_offload_rx()
it calls tls_sw_free_resources_rx() to clean up software context
state.

Unfortunately, tls_sw_free_resources_rx() does not free all
the state tls_set_sw_offload() allocated - it leaks IV and
sequence number buffers.  All other code paths which lead to
tls_sw_release_resources_rx() (which tls_sw_free_resources_rx()
calls) free those right before the call.

Avoid the leak by moving freeing of iv and rec_seq into
tls_sw_release_resources_rx().

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 --
 net/tls/tls_main.c   | 5 +----
 net/tls/tls_sw.c     | 3 +++
 3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index 1b5f55cac613..cc0256939eb6 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -941,8 +941,6 @@ void tls_device_offload_cleanup_rx(struct sock *sk)
        }
 out:
        up_read(&device_offload_lock);
-       kfree(tls_ctx->rx.rec_seq);
-       kfree(tls_ctx->rx.iv);
        tls_sw_release_resources_rx(sk);
 }
 
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index 9547cea0ce3b..478603f43964 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -293,11 +293,8 @@ static void tls_sk_proto_close(struct sock *sk, long 
timeout)
 #endif
        }
 
-       if (ctx->rx_conf == TLS_SW) {
-               kfree(ctx->rx.rec_seq);
-               kfree(ctx->rx.iv);
+       if (ctx->rx_conf == TLS_SW)
                tls_sw_free_resources_rx(sk);
-       }
 
 #ifdef CONFIG_TLS_DEVICE
        if (ctx->rx_conf == TLS_HW)
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index b50ced862f6f..29d6af43dd24 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -2078,6 +2078,9 @@ void tls_sw_release_resources_rx(struct sock *sk)
        struct tls_context *tls_ctx = tls_get_ctx(sk);
        struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
 
+       kfree(tls_ctx->rx.rec_seq);
+       kfree(tls_ctx->rx.iv);
+
        if (ctx->aead_recv) {
                kfree_skb(ctx->recv_pkt);
                ctx->recv_pkt = NULL;
-- 
2.21.0