tls: fix lockless read of strp->msg_ready in ->poll

[ Upstream commit 0844370 ] tls_sk_poll is called without locking the socket, and needs to read strp->msg_ready (via tls_strp_msg_ready). Convert msg_ready to a bool and use READ_ONCE/WRITE_ONCE where needed. The remaining reads are only performed when the socket is locked. Fixes: 121dca7 ("tls: suppress wakeups unless we have a full record") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://lore.kernel.org/r/0b7ee062319037cf86af6b317b3d72f7bfcd2e97.1713797701.git.sd@queasysnail.net Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
xanmod · May 2, 2024 · 4e40e62 · 4e40e62
1 parent 77df3da
commit 4e40e62
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Showing 3 changed files with 6 additions and 5 deletions.
diff --git a/include/net/tls.h b/include/net/tls.h
@@ -110,7 +110,8 @@ struct tls_strparser {
 	u32 stopped : 1;
 	u32 copy_mode : 1;
 	u32 mixed_decrypted : 1;
-	u32 msg_ready : 1;
+
+	bool msg_ready;
 
 	struct strp_msg stm;
 

diff --git a/net/tls/tls.h b/net/tls/tls.h
@@ -212,7 +212,7 @@ static inline struct sk_buff *tls_strp_msg(struct tls_sw_context_rx *ctx)
 
 static inline bool tls_strp_msg_ready(struct tls_sw_context_rx *ctx)
 {
-	return ctx->strp.msg_ready;
+	return READ_ONCE(ctx->strp.msg_ready);
 }
 
 static inline bool tls_strp_msg_mixed_decrypted(struct tls_sw_context_rx *ctx)

diff --git a/net/tls/tls_strp.c b/net/tls/tls_strp.c
@@ -360,7 +360,7 @@ static int tls_strp_copyin(read_descriptor_t *desc, struct sk_buff *in_skb,
 	if (strp->stm.full_len && strp->stm.full_len == skb->len) {
 		desc->count = 0;
 
-		strp->msg_ready = 1;
+		WRITE_ONCE(strp->msg_ready, 1);
 		tls_rx_msg_ready(strp);
 	}
 
@@ -528,7 +528,7 @@ static int tls_strp_read_sock(struct tls_strparser *strp)
 	if (!tls_strp_check_queue_ok(strp))
 		return tls_strp_read_copy(strp, false);
 
-	strp->msg_ready = 1;
+	WRITE_ONCE(strp->msg_ready, 1);
 	tls_rx_msg_ready(strp);
 
 	return 0;
@@ -580,7 +580,7 @@ void tls_strp_msg_done(struct tls_strparser *strp)
 	else
 		tls_strp_flush_anchor_copy(strp);
 
-	strp->msg_ready = 0;
+	WRITE_ONCE(strp->msg_ready, 0);
 	memset(&strp->stm, 0, sizeof(strp->stm));
 
 	tls_strp_check_rcv(strp);