From: He Zhe <zhe.he@xxxxxxxxxxxxx>
[ 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@xxxxxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Fixes: 4400ac8a9a90 ("perf cpumap: Introduce cpu_map__snprint_mask()")
Link: http://lkml.kernel.org/r/1564734592-15624-2-git-send-email-zhe.he@xxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 0b599229bc7e9..0aba5b39c21ef 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
