4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> commit bdf23a9a190d7ecea092fd5c4aabb7d4bd0a9980 upstream. The size of dirent->dt_name is NAME_MAX + 1, but the size for the 'path' buffer is hard coded at 256, which may truncate it because we also prepend "/proc/", so that all that into account and thank gcc 7 for this warning: /git/linux/tools/perf/util/thread_map.c: In function 'thread_map__new_by_uid': /git/linux/tools/perf/util/thread_map.c:119:39: error: '%s' directive output may be truncated writing up to 255 bytes into a region of size 250 [-Werror=format-truncation=] snprintf(path, sizeof(path), "/proc/%s", dirent->d_name); ^~ In file included from /usr/include/stdio.h:939:0, from /git/linux/tools/perf/util/thread_map.c:5: /usr/include/bits/stdio2.h:64:10: note: '__builtin___snprintf_chk' output between 7 and 262 bytes into a destination of size 256 return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ __bos (__s), __fmt, __va_arg_pack ()); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx> Cc: David Ahern <dsahern@xxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Wang Nan <wangnan0@xxxxxxxxxx> Link: http://lkml.kernel.org/n/tip-csy0r8zrvz5efccgd4k12c82@xxxxxxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/perf/util/thread_map.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/tools/perf/util/thread_map.c +++ b/tools/perf/util/thread_map.c @@ -92,7 +92,7 @@ struct thread_map *thread_map__new_by_ui { DIR *proc; int max_threads = 32, items, i; - char path[256]; + char path[NAME_MAX + 1 + 6]; struct dirent dirent, *next, **namelist = NULL; struct thread_map *threads = thread_map__alloc(max_threads);