[PATCH 2/3] Prevent buffer overflow in dump_log_entry

[Petr Tesarik]

One message may be longer than BUFSIZE. In that case, the output
buffer overflows, causing stack corruption. Solve it by flushing
the buffer when it gets full.

Signed-off-by: Petr Tesarik <ptesarik at suse.cz>
---
 makedumpfile.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/makedumpfile.c b/makedumpfile.c
index fc4ce19..261e1ad 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -3885,6 +3885,12 @@ dump_log_entry(char *logptr, int fp)
 	bufp += sprintf(buf, "[%5lld.%06ld] ", nanos, rem/1000);
 
 	for (i = 0, p = msg; i < text_len; i++, p++) {
+		if (bufp - buf >= sizeof(buf) - 6) {
+			if (write(info->fd_dumpfile, buf, bufp - buf) < 0)
+				return FALSE;
+			bufp = buf;
+		}
+
 		if (isprint(*p) || isspace(*p))
 			bufp =+ sprintf(bufp, "%c", *p);
 		else
-- 
1.8.4.5