diff mbox series

bpf: Clean up all resources when register_fprobe_ips returns an error

Message ID 20221025080628.523300-1-nashuiliang@gmail.com
State New
Headers
Series bpf: Clean up all resources when register_fprobe_ips returns an error |

Commit Message

Chuang Wang Oct. 25, 2022, 8:06 a.m. UTC 
  When register_fprobe_ips returns an error, bpf_link_cleanup just cleans
up bpf_link_primer's resources and forgets to clean up
bpf_kprobe_multi_link, addrs, cookies.

So, by adding 'goto error', this ensures that all resources are cleaned
up.

Cc: stable@vger.kernel.org
Fixes: 0dcac2725406 ("bpf: Add multi kprobe link")
Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
---
 kernel/trace/bpf_trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Jiri Olsa Oct. 25, 2022, 9:01 a.m. UTC | #1 
On Tue, Oct 25, 2022 at 04:06:28PM +0800, Chuang Wang wrote:
> When register_fprobe_ips returns an error, bpf_link_cleanup just cleans
> up bpf_link_primer's resources and forgets to clean up
> bpf_kprobe_multi_link, addrs, cookies.
> 
> So, by adding 'goto error', this ensures that all resources are cleaned
> up.
> 
> Cc: stable@vger.kernel.org
> Fixes: 0dcac2725406 ("bpf: Add multi kprobe link")
> Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
> ---
>  kernel/trace/bpf_trace.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 1ed08967fb97..5b806ef20857 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -2778,7 +2778,7 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
>  	err = register_fprobe_ips(&link->fp, addrs, cnt);
>  	if (err) {
>  		bpf_link_cleanup(&link_primer);
> -		return err;
> +		goto error;

that should be taken care of bpf_kprobe_multi_link_dealloc,
through the fput path in bpf_link_cleanup

do you see any related memory leak like report in kmemleak?

jirka

>  	}
>  
>  	return bpf_link_settle(&link_primer);
> -- 
> 2.34.1
>
Chuang Wang Oct. 25, 2022, 9:36 a.m. UTC | #2 
Sorry, I didn't notice this.

On Tue, Oct 25, 2022 at 5:01 PM Jiri Olsa <olsajiri@gmail.com> wrote:
>
> On Tue, Oct 25, 2022 at 04:06:28PM +0800, Chuang Wang wrote:
> > When register_fprobe_ips returns an error, bpf_link_cleanup just cleans
> > up bpf_link_primer's resources and forgets to clean up
> > bpf_kprobe_multi_link, addrs, cookies.
> >
> > So, by adding 'goto error', this ensures that all resources are cleaned
> > up.
> >
> > Cc: stable@vger.kernel.org
> > Fixes: 0dcac2725406 ("bpf: Add multi kprobe link")
> > Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
> > ---
> >  kernel/trace/bpf_trace.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> > index 1ed08967fb97..5b806ef20857 100644
> > --- a/kernel/trace/bpf_trace.c
> > +++ b/kernel/trace/bpf_trace.c
> > @@ -2778,7 +2778,7 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
> >       err = register_fprobe_ips(&link->fp, addrs, cnt);
> >       if (err) {
> >               bpf_link_cleanup(&link_primer);
> > -             return err;
> > +             goto error;
>
> that should be taken care of bpf_kprobe_multi_link_dealloc,
> through the fput path in bpf_link_cleanup
>
> do you see any related memory leak like report in kmemleak?
>
> jirka
>
> >       }
> >
> >       return bpf_link_settle(&link_primer);
> > --
> > 2.34.1
> >
diff mbox series

Patch

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 1ed08967fb97..5b806ef20857 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2778,7 +2778,7 @@  int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
 	err = register_fprobe_ips(&link->fp, addrs, cnt);
 	if (err) {
 		bpf_link_cleanup(&link_primer);
-		return err;
+		goto error;
 	}
 
 	return bpf_link_settle(&link_primer);