Messages in this thread Patch in this message | | | From | <> | Subject | [PATCH 2/2] perf: Fix writing to illegal memory in handling cpumap mask | Date | Fri, 2 Aug 2019 16:29:52 +0800 |
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From: He Zhe <zhe.he@windriver.com>
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> --- 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 3acfbe3..39cce66 100644 --- a/tools/perf/util/cpumap.c +++ b/tools/perf/util/cpumap.c @@ -751,7 +751,10 @@ 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; -- 2.7.4
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