Commit 5f5e25f1 authored Aug 02, 2019 by He Zhe Committed by Arnaldo Carvalho de Melo Aug 08, 2019

perf cpumap: Fix writing to illegal memory in handling cpumap mask



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: 4400ac8a ("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>

parent cf30ae72

tools/perf/util/cpumap.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -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;

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