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authorJann Horn <jannh@google.com>2019-02-20 17:54:43 +0100
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2019-02-21 10:35:10 -0500
commit83540fbc8812a580b6ad8f93f4c29e62e417687e (patch)
treebbced260938642e388e780d28245bea212f25934
parentb689269bd1bb7b1bffb01c1d2d212e66b54f2eb2 (diff)
downloadlinux-83540fbc8812a580b6ad8f93f4c29e62e417687e.tar.bz2
tracing/perf: Use strndup_user() instead of buggy open-coded version
The first version of this method was missing the check for `ret == PATH_MAX`; then such a check was added, but it didn't call kfree() on error, so there was still a small memory leak in the error case. Fix it by using strndup_user() instead of open-coding it. Link: http://lkml.kernel.org/r/20190220165443.152385-1-jannh@google.com Cc: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Fixes: 0eadcc7a7bc0 ("perf/core: Fix perf_uprobe_init()") Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-rw-r--r--kernel/trace/trace_event_perf.c16
1 files changed, 7 insertions, 9 deletions
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 76217bbef815..4629a6104474 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -299,15 +299,13 @@ int perf_uprobe_init(struct perf_event *p_event,
if (!p_event->attr.uprobe_path)
return -EINVAL;
- path = kzalloc(PATH_MAX, GFP_KERNEL);
- if (!path)
- return -ENOMEM;
- ret = strncpy_from_user(
- path, u64_to_user_ptr(p_event->attr.uprobe_path), PATH_MAX);
- if (ret == PATH_MAX)
- return -E2BIG;
- if (ret < 0)
- goto out;
+
+ path = strndup_user(u64_to_user_ptr(p_event->attr.uprobe_path),
+ PATH_MAX);
+ if (IS_ERR(path)) {
+ ret = PTR_ERR(path);
+ return (ret == -EINVAL) ? -E2BIG : ret;
+ }
if (path[0] == '\0') {
ret = -EINVAL;
goto out;