tracing/probes: Fix memory leak in traceprobe_parse_probe_arg_body()

[PATCH v3] tracing/probes: Fix memory leak in traceprobe_parse_probe_arg_body()

Posted by lumingyindetect@126.com 1 year, 7 months ago

From: LuMingYin <lumingyindetect@126.com>

If traceprobe_parse_probe_arg_body() failed to allocate 'parg->fmt',
it jumps to the label 'out' instead of 'fail' by mistake.In the result,
the buffer 'tmp' is not freed in this case and leaks its memory.

Thus jump to the label 'fail' in that error case.

Fixes: 032330abd08b ("tracing/probes: Cleanup probe argument parser")
Signed-off-by: LuMingYin <lumingyindetect@126.com>
---
 kernel/trace/trace_probe.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index c09fa6fc636e..81c319b92038 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -1466,7 +1466,7 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
 		parg->fmt = kmalloc(len, GFP_KERNEL);
 		if (!parg->fmt) {
 			ret = -ENOMEM;
-			goto out;
+			goto fail;
 		}
 		snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
 			 parg->count);
-- 
2.25.1

Re: [PATCH v3] tracing/probes: Fix memory leak in traceprobe_parse_probe_arg_body()

Posted by Masami Hiramatsu (Google) 1 year, 7 months ago

Hi LuMing,

On Sat, 27 Apr 2024 08:23:47 +0100
lumingyindetect@126.com wrote:

> From: LuMingYin <lumingyindetect@126.com>
> 
> If traceprobe_parse_probe_arg_body() failed to allocate 'parg->fmt',
> it jumps to the label 'out' instead of 'fail' by mistake.In the result,
> the buffer 'tmp' is not freed in this case and leaks its memory.
> 
> Thus jump to the label 'fail' in that error case.
> 

Looks good to me.

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>


Thank you!

> Fixes: 032330abd08b ("tracing/probes: Cleanup probe argument parser")
> Signed-off-by: LuMingYin <lumingyindetect@126.com>
> ---
>  kernel/trace/trace_probe.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> index c09fa6fc636e..81c319b92038 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -1466,7 +1466,7 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
>  		parg->fmt = kmalloc(len, GFP_KERNEL);
>  		if (!parg->fmt) {
>  			ret = -ENOMEM;
> -			goto out;
> +			goto fail;
>  		}
>  		snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
>  			 parg->count);
> -- 
> 2.25.1
> 
> 


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>

Re: [v3] tracing/probes: Fix memory leak in traceprobe_parse_probe_arg_body()

Posted by Markus Elfring 1 year, 7 months ago

…
> > it jumps to the label 'out' instead of 'fail' by mistake.In the result,
…
>
> Looks good to me.

* Do you care for a typo in this change description?

* Would you like to read any improved (patch) version descriptions (or changelogs)?

Regards,
Markus

Re: [v3] tracing/probes: Fix memory leak in traceprobe_parse_probe_arg_body()

Posted by Masami Hiramatsu (Google) 1 year, 7 months ago

On Mon, 29 Apr 2024 15:55:09 +0200
Markus Elfring <Markus.Elfring@web.de> wrote:

> …
> > > it jumps to the label 'out' instead of 'fail' by mistake.In the result,
> …
> >
> > Looks good to me.
> 
> * Do you care for a typo in this change description?
> 
> * Would you like to read any improved (patch) version descriptions (or changelogs)?

Thanks, but those are nitpicks and I don't mind it.

Thank you,

> 
> Regards,
> Markus


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>

Re: [PATCH v3] tracing/probes: Fix memory leak in traceprobe_parse_probe_arg_body()

Posted by Markus Elfring 1 year, 7 months ago

>                                             … by mistake.In the result,
…

I propose once more to start the second sentence of this change description
on a subsequent line.

> ---
> kernel/trace/trace_probe.c | 2 +-
…

Unfortunately, you overlooked to add patch version descriptions behind the marker line.

See also:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.9-rc5#n713

Regards,
Markus