netdev - [PATCH net] net/tls: make sure offload also gets the keys wiped

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Message-Id: <20190628231139.16842-1-jakub.kicinski@netronome.com>
Date:   Fri, 28 Jun 2019 16:11:39 -0700
From:   Jakub Kicinski <jakub.kicinski@...ronome.com>
To:     davem@...emloft.net, john.fastabend@...il.com
Cc:     netdev@...r.kernel.org, oss-drivers@...ronome.com,
        alexei.starovoitov@...il.com, sd@...asysnail.net,
        Jakub Kicinski <jakub.kicinski@...ronome.com>,
        Dirk van der Merwe <dirk.vandermerwe@...ronome.com>
Subject: [PATCH net] net/tls: make sure offload also gets the keys wiped

Commit 86029d10af18 ("tls: zero the crypto information from tls_context
before freeing") added memzero_explicit() calls to clear the key material
before freeing struct tls_context, but it missed tls_device.c has its
own way of freeing this structure. Replace the missing free.

Fixes: 86029d10af18 ("tls: zero the crypto information from tls_context before freeing")
Signed-off-by: Jakub Kicinski <jakub.kicinski@...ronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@...ronome.com>
---
John, this will definitely conflict with your fix, but I'm not sure
how close we are to closure, so perhaps it's not the worst idea to
do this small fix and at least have all the contexts freed by a
common helper? I'm happy to drop this if you prefer.
---
 include/net/tls.h    | 1 +
 net/tls/tls_device.c | 2 +-
 net/tls/tls_main.c   | 4 ++--
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/net/tls.h b/include/net/tls.h
index 53d96bca220d..889df0312cd1 100644
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -313,6 +313,7 @@ struct tls_offload_context_rx {
 	(ALIGN(sizeof(struct tls_offload_context_rx), sizeof(void *)) + \
 	 TLS_DRIVER_STATE_SIZE)
 
+void tls_ctx_free(struct tls_context *ctx);
 int wait_on_pending_writer(struct sock *sk, long *timeo);
 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
 		int __user *optlen);
diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index 397990407ed6..eb8f24f420f0 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -61,7 +61,7 @@ static void tls_device_free_ctx(struct tls_context *ctx)
 	if (ctx->rx_conf == TLS_HW)
 		kfree(tls_offload_ctx_rx(ctx));
 
-	kfree(ctx);
+	tls_ctx_free(ctx);
 }
 
 static void tls_device_gc_task(struct work_struct *work)
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index e2b69e805d46..4674e57e66b0 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -251,7 +251,7 @@ static void tls_write_space(struct sock *sk)
 	ctx->sk_write_space(sk);
 }
 
-static void tls_ctx_free(struct tls_context *ctx)
+void tls_ctx_free(struct tls_context *ctx)
 {
 	if (!ctx)
 		return;
@@ -643,7 +643,7 @@ static void tls_hw_sk_destruct(struct sock *sk)
 
 	ctx->sk_destruct(sk);
 	/* Free ctx */
-	kfree(ctx);
+	tls_ctx_free(ctx);
 	icsk->icsk_ulp_data = NULL;
 }
 
-- 
2.21.0