Fix: client_sequence_number may dereference NULL pointer

Found by Coverity:
CID 1400710 (#1 of 1): Dereference null return value (NULL_RETURNS)
3. dereference: Dereferencing a null pointer header.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/liblttng-ust/lttng-ring-buffer-client.h b/liblttng-ust/lttng-ring-buffer-client.h
index a261dcfe02e01cf0eba9d69626cdc83270078d10..f02d2808d458b0908b42289dabdbca4c877ed122 100644 (file)
--- a/liblttng-ust/lttng-ring-buffer-client.h
+++ b/liblttng-ust/lttng-ring-buffer-client.h
@@ -583,6 +583,8 @@ static int client_sequence_number(struct lttng_ust_lib_ring_buffer *buf,
        struct packet_header *header;
 
        header = client_packet_header(buf, handle);
+       if (!header)
+               return -1;
        *seq = header->ctx.packet_seq_num;
        return 0;
 }