[SRU][M][PATCH 2/8] tls: extract context alloc/initialization out of tls_set_sw_offload

[Juerg Haefliger]

From: Sabrina Dubroca <sd at queasysnail.net>

CVE-2024-26583

[ Upstream commit 615580cbc99af0da2d1c7226fab43a3d5003eb97 ]

Simplify tls_set_sw_offload a bit.

Signed-off-by: Sabrina Dubroca <sd at queasysnail.net>
Signed-off-by: David S. Miller <davem at davemloft.net>
Stable-dep-of: aec7961916f3 ("tls: fix race between async notify and socket close")
Signed-off-by: Sasha Levin <sashal at kernel.org>
(cherry picked from commit 5e01c54ebcaff527ccf58dfea4392090ed159721 linux-6.6.y)
Signed-off-by: Juerg Haefliger <juerg.haefliger at canonical.com>
---
 net/tls/tls_sw.c | 86 ++++++++++++++++++++++++++++--------------------
 1 file changed, 51 insertions(+), 35 deletions(-)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 882738d83f17..cefa668bcd0b 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -2498,6 +2498,48 @@ void tls_update_rx_zc_capable(struct tls_context *tls_ctx)
 		tls_ctx->prot_info.version != TLS_1_3_VERSION;
 }
 
+static struct tls_sw_context_tx *init_ctx_tx(struct tls_context *ctx, struct sock *sk)
+{
+	struct tls_sw_context_tx *sw_ctx_tx;
+
+	if (!ctx->priv_ctx_tx) {
+		sw_ctx_tx = kzalloc(sizeof(*sw_ctx_tx), GFP_KERNEL);
+		if (!sw_ctx_tx)
+			return NULL;
+	} else {
+		sw_ctx_tx = ctx->priv_ctx_tx;
+	}
+
+	crypto_init_wait(&sw_ctx_tx->async_wait);
+	spin_lock_init(&sw_ctx_tx->encrypt_compl_lock);
+	INIT_LIST_HEAD(&sw_ctx_tx->tx_list);
+	INIT_DELAYED_WORK(&sw_ctx_tx->tx_work.work, tx_work_handler);
+	sw_ctx_tx->tx_work.sk = sk;
+
+	return sw_ctx_tx;
+}
+
+static struct tls_sw_context_rx *init_ctx_rx(struct tls_context *ctx)
+{
+	struct tls_sw_context_rx *sw_ctx_rx;
+
+	if (!ctx->priv_ctx_rx) {
+		sw_ctx_rx = kzalloc(sizeof(*sw_ctx_rx), GFP_KERNEL);
+		if (!sw_ctx_rx)
+			return NULL;
+	} else {
+		sw_ctx_rx = ctx->priv_ctx_rx;
+	}
+
+	crypto_init_wait(&sw_ctx_rx->async_wait);
+	spin_lock_init(&sw_ctx_rx->decrypt_compl_lock);
+	init_waitqueue_head(&sw_ctx_rx->wq);
+	skb_queue_head_init(&sw_ctx_rx->rx_list);
+	skb_queue_head_init(&sw_ctx_rx->async_hold);
+
+	return sw_ctx_rx;
+}
+
 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
 {
 	struct tls_context *tls_ctx = tls_get_ctx(sk);
@@ -2519,48 +2561,22 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
 	}
 
 	if (tx) {
-		if (!ctx->priv_ctx_tx) {
-			sw_ctx_tx = kzalloc(sizeof(*sw_ctx_tx), GFP_KERNEL);
-			if (!sw_ctx_tx) {
-				rc = -ENOMEM;
-				goto out;
-			}
-			ctx->priv_ctx_tx = sw_ctx_tx;
-		} else {
-			sw_ctx_tx =
-				(struct tls_sw_context_tx *)ctx->priv_ctx_tx;
-		}
-	} else {
-		if (!ctx->priv_ctx_rx) {
-			sw_ctx_rx = kzalloc(sizeof(*sw_ctx_rx), GFP_KERNEL);
-			if (!sw_ctx_rx) {
-				rc = -ENOMEM;
-				goto out;
-			}
-			ctx->priv_ctx_rx = sw_ctx_rx;
-		} else {
-			sw_ctx_rx =
-				(struct tls_sw_context_rx *)ctx->priv_ctx_rx;
-		}
-	}
+		ctx->priv_ctx_tx = init_ctx_tx(ctx, sk);
+		if (!ctx->priv_ctx_tx)
+			return -ENOMEM;
 
-	if (tx) {
-		crypto_init_wait(&sw_ctx_tx->async_wait);
-		spin_lock_init(&sw_ctx_tx->encrypt_compl_lock);
+		sw_ctx_tx = ctx->priv_ctx_tx;
 		crypto_info = &ctx->crypto_send.info;
 		cctx = &ctx->tx;
 		aead = &sw_ctx_tx->aead_send;
-		INIT_LIST_HEAD(&sw_ctx_tx->tx_list);
-		INIT_DELAYED_WORK(&sw_ctx_tx->tx_work.work, tx_work_handler);
-		sw_ctx_tx->tx_work.sk = sk;
 	} else {
-		crypto_init_wait(&sw_ctx_rx->async_wait);
-		spin_lock_init(&sw_ctx_rx->decrypt_compl_lock);
-		init_waitqueue_head(&sw_ctx_rx->wq);
+		ctx->priv_ctx_rx = init_ctx_rx(ctx);
+		if (!ctx->priv_ctx_rx)
+			return -ENOMEM;
+
+		sw_ctx_rx = ctx->priv_ctx_rx;
 		crypto_info = &ctx->crypto_recv.info;
 		cctx = &ctx->rx;
-		skb_queue_head_init(&sw_ctx_rx->rx_list);
-		skb_queue_head_init(&sw_ctx_rx->async_hold);
 		aead = &sw_ctx_rx->aead_recv;
 	}
 
-- 
2.40.1