Re: [PATCH v2] perf probe: Verify parameters for two functions

From: Wangnan (F)
Date: Wed Nov 11 2015 - 02:01:41 EST


Hi Arnaldo,

Could you please collect this patch to your tree? It fixes a segfault
when only one of kprobe and uprobe is enabled.

Thank you.

On 2015/11/6 17:50, Wang Nan wrote:
On kernel with only one of CONFIG_KPROBE_EVENTS and
CONFIG_UPROBE_EVENTS enabled, 'perf probe -d' causes segfault because
perf_del_probe_events() calls probe_file__get_events() with a negative
fd.

This patch fixes it by add parameter validation at the entry of
probe_file__get_events() and probe_file__get_rawlist(). Since they are
both non-static public functions (in .h file), parameter verifying
is required.

v1 -> v2: Verify fd at the head of probe_file__get_rawlist() instead of
checking at call site (suggested by Masami and Arnaldo at [1,2]).

[1] http://lkml.kernel.org/r/50399556C9727B4D88A595C8584AAB37526048E3@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
[2] http://lkml.kernel.org/r/20151105155830.GV13236@xxxxxxxxxx

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/probe-file.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index 89dbeb9..e3b3b92 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -138,6 +138,9 @@ struct strlist *probe_file__get_rawlist(int fd)
char *p;
struct strlist *sl;
+ if (fd < 0)
+ return NULL;
+
sl = strlist__new(NULL, NULL);
fp = fdopen(dup(fd), "r");
@@ -271,6 +274,9 @@ int probe_file__get_events(int fd, struct strfilter *filter,
const char *p;
int ret = -ENOENT;
+ if (!plist)
+ return -EINVAL;
+
namelist = __probe_file__get_namelist(fd, true);
if (!namelist)
return -ENOENT;


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