Patch "tls: rx: strp: force mixed decrypted records into copy mode" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    tls: rx: strp: force mixed decrypted records into copy mode

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     tls-rx-strp-force-mixed-decrypted-records-into-copy-.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 200b14455e14910ea81e13833331928828c347fc
Author: Jakub Kicinski <kuba@xxxxxxxxxx>
Date:   Tue May 16 18:50:38 2023 -0700

    tls: rx: strp: force mixed decrypted records into copy mode
    
    [ Upstream commit 14c4be92ebb3e36e392aa9dd8f314038a9f96f3c ]
    
    If a record is partially decrypted we'll have to CoW it, anyway,
    so go into copy mode and allocate a writable skb right away.
    
    This will make subsequent fix simpler because we won't have to
    teach tls_strp_msg_make_copy() how to copy skbs while preserving
    decrypt status.
    
    Tested-by: Shai Amiram <samiram@xxxxxxxxxx>
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Stable-dep-of: eca9bfafee3a ("tls: rx: strp: preserve decryption status of skbs when needed")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 20ca1613f2e3e..cc5ed2cf25f65 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1567,6 +1567,16 @@ static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
 	to->l4_hash = from->l4_hash;
 };
 
+static inline int skb_cmp_decrypted(const struct sk_buff *skb1,
+				    const struct sk_buff *skb2)
+{
+#ifdef CONFIG_TLS_DEVICE
+	return skb2->decrypted - skb1->decrypted;
+#else
+	return 0;
+#endif
+}
+
 static inline void skb_copy_decrypted(struct sk_buff *to,
 				      const struct sk_buff *from)
 {
diff --git a/net/tls/tls_strp.c b/net/tls/tls_strp.c
index 9889df5ce0660..e2e48217e7ac9 100644
--- a/net/tls/tls_strp.c
+++ b/net/tls/tls_strp.c
@@ -326,15 +326,19 @@ static int tls_strp_read_copy(struct tls_strparser *strp, bool qshort)
 	return 0;
 }
 
-static bool tls_strp_check_no_dup(struct tls_strparser *strp)
+static bool tls_strp_check_queue_ok(struct tls_strparser *strp)
 {
 	unsigned int len = strp->stm.offset + strp->stm.full_len;
-	struct sk_buff *skb;
+	struct sk_buff *first, *skb;
 	u32 seq;
 
-	skb = skb_shinfo(strp->anchor)->frag_list;
-	seq = TCP_SKB_CB(skb)->seq;
+	first = skb_shinfo(strp->anchor)->frag_list;
+	skb = first;
+	seq = TCP_SKB_CB(first)->seq;
 
+	/* Make sure there's no duplicate data in the queue,
+	 * and the decrypted status matches.
+	 */
 	while (skb->len < len) {
 		seq += skb->len;
 		len -= skb->len;
@@ -342,6 +346,8 @@ static bool tls_strp_check_no_dup(struct tls_strparser *strp)
 
 		if (TCP_SKB_CB(skb)->seq != seq)
 			return false;
+		if (skb_cmp_decrypted(first, skb))
+			return false;
 	}
 
 	return true;
@@ -422,7 +428,7 @@ static int tls_strp_read_sock(struct tls_strparser *strp)
 			return tls_strp_read_copy(strp, true);
 	}
 
-	if (!tls_strp_check_no_dup(strp))
+	if (!tls_strp_check_queue_ok(strp))
 		return tls_strp_read_copy(strp, false);
 
 	strp->msg_ready = 1;