lkml.org 
[lkml]   [2019]   [Aug]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.14 33/62] perf cpumap: Fix writing to illegal memory in handling cpumap mask
Date
[ Upstream commit 5f5e25f1c7933a6e1673515c0b1d5acd82fea1ed ]

cpu_map__snprint_mask() would write to illegal memory pointed by
zalloc(0) when there is only one cpu.

This patch fixes the calculation and adds sanity check against the input
parameters.

Signed-off-by: He Zhe <zhe.he@windriver.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Fixes: 4400ac8a9a90 ("perf cpumap: Introduce cpu_map__snprint_mask()")
Link: http://lkml.kernel.org/r/1564734592-15624-2-git-send-email-zhe.he@windriver.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/util/cpumap.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index 383674f448fcd..f93846edc1e0d 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -701,7 +701,10 @@ size_t cpu_map__snprint_mask(struct cpu_map *map, char *buf, size_t size)
unsigned char *bitmap;
int last_cpu = cpu_map__cpu(map, map->nr - 1);

- bitmap = zalloc((last_cpu + 7) / 8);
+ if (buf == NULL)
+ return 0;
+
+ bitmap = zalloc(last_cpu / 8 + 1);
if (bitmap == NULL) {
buf[0] = '\0';
return 0;
--
2.20.1


\
 
 \ /
  Last update: 2019-08-27 09:53    [W:0.343 / U:0.228 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site