From a78604defffbc1da1497a8c8b48275b723eb5946 Mon Sep 17 00:00:00 2001 From: He Kuang Date: Wed, 4 Mar 2015 18:01:42 +0800 Subject: [PATCH] perf probe: Fix possible double free on error A double free occurred when get source file path failed. If lr->path failed to assign a new value, it will be freed as the old path and then be freed again during line_range__clear(), and causes this: $ perf probe -L do_execve -k vmlinux *** Error in `/usr/bin/perf': double free or corruption (fasttop): 0x0000000000a9ac50 *** ======= Backtrace: ========= ../lib64/libc.so.6(+0x6eeef)[0x7ffff5e44eef] ../lib64/libc.so.6(+0x78cae)[0x7ffff5e4ecae] ../lib64/libc.so.6(+0x79987)[0x7ffff5e4f987] ../bin/perf[0x4ab41f] ... This patch fix this problem. Signed-off-by: He Kuang Acked-by: Masami Hiramatsu Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1425463302-1687-1-git-send-email-hekuang@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 8af8e7f55254..e2bf620f98cb 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -790,7 +790,11 @@ static int __show_line_range(struct line_range *lr, const char *module, /* Convert source file path */ tmp = lr->path; ret = get_real_path(tmp, lr->comp_dir, &lr->path); - free(tmp); /* Free old path */ + + /* Free old path when new path is assigned */ + if (tmp != lr->path) + free(tmp); + if (ret < 0) { pr_warning("Failed to find source file path.\n"); return ret; -- 2.20.1