net: tcp2: fix unaligned access in the TCP2 stack

The TCP2 stack does operations directly on the packet data which may or may not be aligned. The unaligned access causes a fault on the Cortex-M0+ so use the UNALIGNED_* macros instead. Signed-off-by: Michael Hope <mlhx@google.com>
zephyrproject-rtos · Jul 22, 2020 · b046ca5 · b046ca5
1 parent 71e7cd3
commit b046ca5
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Showing 2 changed files with 7 additions and 5 deletions.
diff --git a/subsys/net/ip/tcp2.c b/subsys/net/ip/tcp2.c
@@ -508,7 +508,8 @@ static bool tcp_options_check(struct tcp_options *recv_options,
 				goto end;
 			}
 
-			recv_options->mss = ntohs(*((uint16_t *)(options + 2)));
+			recv_options->mss =
+				ntohs(UNALIGNED_GET((uint16_t *)(options + 2)));
 			recv_options->mss_found = true;
 			NET_DBG("MSS=%hu", recv_options->mss);
 			break;

diff --git a/subsys/net/ip/tcp2_priv.h b/subsys/net/ip/tcp2_priv.h
@@ -12,8 +12,8 @@
 #define MIN3(_a, _b, _c) MIN((_a), MIN((_b), (_c)))
 #endif
 
-#define th_seq(_x) ntohl((_x)->th_seq)
-#define th_ack(_x) ntohl((_x)->th_ack)
+#define th_seq(_x) ntohl(UNALIGNED_GET(&(_x)->th_seq))
+#define th_ack(_x) ntohl(UNALIGNED_GET(&(_x)->th_ack))
 
 #define tcp_slist(_slist, _op, _type, _link)				\
 ({									\
@@ -211,8 +211,9 @@ struct tcp { /* TCP connection */
 ({									\
 	bool result = false;						\
 									\
-	if (*(_fl) && (_cond) && (*(_fl) _op (_mask))) {		\
-		*(_fl) &= ~(_mask);					\
+	if (UNALIGNED_GET(_fl) && (_cond) &&				\
+	    (UNALIGNED_GET(_fl) _op(_mask))) {				\
+		UNALIGNED_PUT(UNALIGNED_GET(_fl) & ~(_mask), _fl);	\
 		result = true;						\
 	}								\
 									\