[tip:perf/urgent] perf tools: Ensure sscanf does not overrun the "mem" field

[tip-bot for Alan Cox <tipbot@zytor.com>]

Commit-ID:  a761a2d8a7175b7b4e8525e0672e1a8d3c051001
Gitweb:     http://git.kernel.org/tip/a761a2d8a7175b7b4e8525e0672e1a8d3c051001
Author:     Alan Cox <alan@linux.intel.com>
AuthorDate: Mon, 20 Jan 2014 19:10:11 +0100
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 20 Jan 2014 16:19:08 -0300

perf tools: Ensure sscanf does not overrun the "mem" field

Make the parsing robust.

(perf has some other assumptions that BUFSIZE <= MAX_PATH which are
 not touched here)

Reported-by: Jackie Chang
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-g2uoiwbrpiimb63rx32qv8ne@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/header.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index bb3e0ed..893f8e2 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -930,7 +930,7 @@ static int write_topo_node(int fd, int node)
 		/* skip over invalid lines */
 		if (!strchr(buf, ':'))
 			continue;
-		if (sscanf(buf, "%*s %*d %s %"PRIu64, field, &mem) != 2)
+		if (sscanf(buf, "%*s %*d %31s %"PRIu64, field, &mem) != 2)
 			goto done;
 		if (!strcmp(field, "MemTotal:"))
 			mem_total = mem;