From: disconnect3d <dominik.b.czarnota@gmail.com> commit db2c549407d4a76563c579e4768f7d6d32afefba upstream. This patch fixes an off-by-one error in strncpy size argument in tools/perf/util/map.c. The issue is that in: strncmp(filename, "/system/lib/", 11) the passed string literal: "/system/lib/" has 12 bytes (without the NULL byte) and the passed size argument is 11. As a result, the logic won't match the ending "/" byte and will pass filepaths that are stored in other directories e.g. "/system/libmalicious/bin" or just "/system/libmalicious". This functionality seems to be present only on Android. I assume the /system/ directory is only writable by the root user, so I don't think this bug has much (or any) security impact. Fixes: eca818369996 ("perf tools: Add automatic remapping of Android libraries") Signed-off-by: disconnect3d <dominik.b.czarnota@gmail.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Changbin Du <changbin.du@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John Keeping <john@metanate.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Lentine <mlentine@google.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20200309104855.3775-1-dominik.b.czarnota@gmail.c... Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- tools/perf/util/map.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c index 1117ab8..d3d3601 100644 --- a/tools/perf/util/map.c +++ b/tools/perf/util/map.c @@ -85,7 +85,7 @@ static inline bool replace_android_lib(const char *filename, char *newfilename) return true; } - if (!strncmp(filename, "/system/lib/", 11)) { + if (!strncmp(filename, "/system/lib/", 12)) { char *ndk, *app; const char *arch; size_t ndk_length; -- 1.8.3