Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 4.19 64/68] perf cpumap: Fix writing to illegal memory in handling cpumap mask | Date | Tue, 13 Aug 2019 22:15:42 -0400 |
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From: He Zhe <zhe.he@windriver.com>
[ 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
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