2015-04-28 08:47:45

by Wang Nan

Subject: [PATCH] perf: probe: avoid segfault if passed with ''.

Since parse_perf_probe_point() deals with a user passed argument, we
should not assume it to be a valid string.

Without this patch, if pass '' to perf probe, a segfault raises:

$ perf probe -a ''
Segmentation fault

This patch checks argument of parse_perf_probe_point() before
string processing.

After this patch:

$ perf probe -a ''

usage: perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]
or: perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]
...

Signed-off-by: Wang Nan <[email protected]>
---
tools/perf/util/probe-event.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index d8bb616..d05b77c 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1084,6 +1084,8 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
*
* TODO:Group name support
*/
+ if (!arg)
+ return -EINVAL;

ptr = strpbrk(arg, ";=@+%");
if (ptr && *ptr == '=') { /* Event name */
--
1.8.3.4

2015-05-04 20:55:29

by Arnaldo Carvalho de Melo

Subject: Re: [PATCH] perf: probe: avoid segfault if passed with ''.

Em Tue, Apr 28, 2015 at 08:46:09AM +0000, Wang Nan escreveu:
> Since parse_perf_probe_point() deals with a user passed argument, we
> should not assume it to be a valid string.
>
> Without this patch, if pass '' to perf probe, a segfault raises:
>
> $ perf probe -a ''
> Segmentation fault
>
> This patch checks argument of parse_perf_probe_point() before
> string processing.
>
> After this patch:
>
> $ perf probe -a ''
>
> usage: perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]
> or: perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]
> ...

Thanks, applied to perf/urgent.

- Arnaldo

2015-05-06 04:37:28

by tip-bot for Vasyl Gomonovych

Subject: [tip:perf/urgent] perf probe: Fix segfault if passed with ''.

Commit-ID: e59d29e88f7b7e3d1231202b0203d0af6f15a440
Gitweb: http://git.kernel.org/tip/e59d29e88f7b7e3d1231202b0203d0af6f15a440
Author: Wang Nan <[email protected]>
AuthorDate: Tue, 28 Apr 2015 08:46:09 +0000
Committer: Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Tue, 5 May 2015 12:26:52 -0300

perf probe: Fix segfault if passed with ''.

Since parse_perf_probe_point() deals with a user passed argument, we
should not assume it to be a valid string.

Without this patch, if pass '' to perf probe, a segfault raises:

$ perf probe -a ''
Segmentation fault

This patch checks argument of parse_perf_probe_point() before
string processing.

After this patch:

$ perf probe -a ''

usage: perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]
or: perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]
...

Signed-off-by: Wang Nan <[email protected]>
Acked-by: Masami Hiramatsu <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Zefan Li <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/util/probe-event.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index d8bb616..d05b77c 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1084,6 +1084,8 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
*
* TODO:Group name support
*/
+ if (!arg)
+ return -EINVAL;

ptr = strpbrk(arg, ";=@+%");
if (ptr && *ptr == '=') { /* Event name */