From b8fdcfb5a17f1d4fd503caef5c457005a765ecd7 Mon Sep 17 00:00:00 2001 From: disconnect3d Date: Mon, 9 Mar 2020 11:48:53 +0100 Subject: [PATCH] perf map: Fix off by one in strncpy() size argument 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 Cc: Alexander Shishkin Cc: Changbin Du Cc: Jiri Olsa Cc: John Keeping Cc: Mark Rutland Cc: Michael Lentine Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Song Liu Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200309104855.3775-1-dominik.b.czarnota@gmail.com Signed-off-by: Arnaldo Carvalho de Melo --- 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 95428511300d..b342f744b1fc 100644 --- a/tools/perf/util/map.c +++ b/tools/perf/util/map.c @@ -89,7 +89,7 @@ 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; -- 2.30.2