Fix: string packet boundary handling, bits vs bytes

Fixes #684

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

diff --git a/formats/ctf/types/string.c b/formats/ctf/types/string.c
index 3dd1414a0e078882160c7de6d28226d7a27b0973..002f1b4fb335f5bb34d776fa79d36b5f9bf83c35 100644 (file)
--- a/formats/ctf/types/string.c
+++ b/formats/ctf/types/string.c
@@ -39,7 +39,7 @@ int ctf_string_read(struct bt_stream_pos *ppos, struct bt_definition *definition
                string_definition->declaration;
        struct ctf_stream_pos *pos = ctf_pos(ppos);
        size_t len;
-       ssize_t max_len;
+       ssize_t max_len_bits;
        char *srcaddr;
 
        if (!ctf_align_pos(pos, string_declaration->p.alignment))
@@ -48,11 +48,12 @@ int ctf_string_read(struct bt_stream_pos *ppos, struct bt_definition *definition
        srcaddr = ctf_get_pos_addr(pos);
        if (pos->offset == EOF)
                return -EFAULT;
-       /* Not counting \0 */
-       max_len = pos->packet_size - pos->offset - 1;
-       if (max_len < 0)
+       /* Not counting \0. Counting in bits. */
+       max_len_bits = pos->packet_size - pos->offset - CHAR_BIT;
+       if (max_len_bits < 0)
                return -EFAULT;
-       len = strnlen(srcaddr, max_len) + 1;    /* Add \0 */
+       /* Add \0, counting in bytes. */
+       len = strnlen(srcaddr, (size_t) max_len_bits / CHAR_BIT) + 1;
        /* Truncated string, unexpected. Trace probably corrupted. */
        if (srcaddr[len - 1] != '\0')
                return -EFAULT;