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* Re: WARNING in bpf_warn_invalid_xdp_action
       [not found] <000000000000a16ad7059cbcbe43@google.com>
@ 2020-01-22 21:01 ` syzbot
  2020-01-22 21:38   ` Eric Dumazet
  2022-02-10  9:29 ` [syzbot] " syzbot
  1 sibling, 1 reply; 5+ messages in thread
From: syzbot @ 2020-01-22 21:01 UTC (permalink / raw)
  To: andriin, ast, bpf, corbet, daniel, davem, dsahern, hawk,
	john.fastabend, kafai, kuba, linux-doc, linux-kernel, netdev,
	songliubraving, syzkaller-bugs, yhs

syzbot has bisected this bug to:

commit 58956317c8de52009d1a38a721474c24aef74fe7
Author: David Ahern <dsahern@gmail.com>
Date:   Fri Dec 7 20:24:57 2018 +0000

    neighbor: Improve garbage collection

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=124a5985e00000
start commit:   d0f41851 net, ip_tunnel: fix namespaces move
git tree:       net
final crash:    https://syzkaller.appspot.com/x/report.txt?x=114a5985e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=164a5985e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d9290aeb7e6cf1c4
dashboard link: https://syzkaller.appspot.com/bug?extid=8ce4113dadc4789fac74
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11f99369e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13d85601e00000

Reported-by: syzbot+8ce4113dadc4789fac74@syzkaller.appspotmail.com
Fixes: 58956317c8de ("neighbor: Improve garbage collection")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: WARNING in bpf_warn_invalid_xdp_action
  2020-01-22 21:01 ` WARNING in bpf_warn_invalid_xdp_action syzbot
@ 2020-01-22 21:38   ` Eric Dumazet
  2020-01-23  6:19     ` Dmitry Vyukov
  0 siblings, 1 reply; 5+ messages in thread
From: Eric Dumazet @ 2020-01-22 21:38 UTC (permalink / raw)
  To: syzbot, andriin, ast, bpf, corbet, daniel, davem, dsahern, hawk,
	john.fastabend, kafai, kuba, linux-doc, linux-kernel, netdev,
	songliubraving, syzkaller-bugs, yhs



On 1/22/20 1:01 PM, syzbot wrote:
> syzbot has bisected this bug to:
> 
> commit 58956317c8de52009d1a38a721474c24aef74fe7
> Author: David Ahern <dsahern@gmail.com>
> Date:   Fri Dec 7 20:24:57 2018 +0000
> 
>     neighbor: Improve garbage collection
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=124a5985e00000
> start commit:   d0f41851 net, ip_tunnel: fix namespaces move
> git tree:       net
> final crash:    https://syzkaller.appspot.com/x/report.txt?x=114a5985e00000
> console output: https://syzkaller.appspot.com/x/log.txt?x=164a5985e00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=d9290aeb7e6cf1c4
> dashboard link: https://syzkaller.appspot.com/bug?extid=8ce4113dadc4789fac74
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11f99369e00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13d85601e00000
> 
> Reported-by: syzbot+8ce4113dadc4789fac74@syzkaller.appspotmail.com
> Fixes: 58956317c8de ("neighbor: Improve garbage collection")
> 
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> 

bisection looks bogus...

It would be nice to have alternative helpers to conveniently replace some WARN_ON/WARN_ONCE/...
and not having to hand-code stuff like :

diff --git a/net/core/filter.c b/net/core/filter.c
index 538f6a735a19f017df8e10149cb578107ddc8cbb..633988f7c81b3b4f015d827ccb485e8b227ad20b 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6913,11 +6913,15 @@ static bool xdp_is_valid_access(int off, int size,
 
 void bpf_warn_invalid_xdp_action(u32 act)
 {
+       static bool __section(.data.once) warned;
        const u32 act_max = XDP_REDIRECT;
 
-       WARN_ONCE(1, "%s XDP return value %u, expect packet loss!\n",
-                 act > act_max ? "Illegal" : "Driver unsupported",
-                 act);
+       if (!warned) {
+               warned = true;
+               pr_err("%s XDP return value %u, expect packet loss!\n",
+                      act > act_max ? "Illegal" : "Driver unsupported", act);
+               dump_stack();
+       }
 }
 EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: WARNING in bpf_warn_invalid_xdp_action
  2020-01-22 21:38   ` Eric Dumazet
@ 2020-01-23  6:19     ` Dmitry Vyukov
  0 siblings, 0 replies; 5+ messages in thread
From: Dmitry Vyukov @ 2020-01-23  6:19 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: syzbot, Andrii Nakryiko, Alexei Starovoitov, bpf, Jonathan Corbet,
	Daniel Borkmann, David Miller, David Ahern, hawk, John Fastabend,
	Martin KaFai Lau, kuba, open list:DOCUMENTATION, LKML, netdev,
	Song Liu, syzkaller-bugs, Yonghong Song

On Wed, Jan 22, 2020 at 10:38 PM Eric Dumazet <eric.dumazet@gmail.com> wrote:
>
>
>
> On 1/22/20 1:01 PM, syzbot wrote:
> > syzbot has bisected this bug to:
> >
> > commit 58956317c8de52009d1a38a721474c24aef74fe7
> > Author: David Ahern <dsahern@gmail.com>
> > Date:   Fri Dec 7 20:24:57 2018 +0000
> >
> >     neighbor: Improve garbage collection
> >
> > bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=124a5985e00000
> > start commit:   d0f41851 net, ip_tunnel: fix namespaces move
> > git tree:       net
> > final crash:    https://syzkaller.appspot.com/x/report.txt?x=114a5985e00000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=164a5985e00000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=d9290aeb7e6cf1c4
> > dashboard link: https://syzkaller.appspot.com/bug?extid=8ce4113dadc4789fac74
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11f99369e00000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13d85601e00000
> >
> > Reported-by: syzbot+8ce4113dadc4789fac74@syzkaller.appspotmail.com
> > Fixes: 58956317c8de ("neighbor: Improve garbage collection")
> >
> > For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> >
>
> bisection looks bogus...
>
> It would be nice to have alternative helpers to conveniently replace some WARN_ON/WARN_ONCE/...
> and not having to hand-code stuff like :
>
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 538f6a735a19f017df8e10149cb578107ddc8cbb..633988f7c81b3b4f015d827ccb485e8b227ad20b 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -6913,11 +6913,15 @@ static bool xdp_is_valid_access(int off, int size,
>
>  void bpf_warn_invalid_xdp_action(u32 act)
>  {
> +       static bool __section(.data.once) warned;
>         const u32 act_max = XDP_REDIRECT;
>
> -       WARN_ONCE(1, "%s XDP return value %u, expect packet loss!\n",
> -                 act > act_max ? "Illegal" : "Driver unsupported",
> -                 act);
> +       if (!warned) {
> +               warned = true;
> +               pr_err("%s XDP return value %u, expect packet loss!\n",
> +                      act > act_max ? "Illegal" : "Driver unsupported", act);
> +               dump_stack();
> +       }
>  }
>  EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);

If a single caller of this function would be enough (or maybe grand
caller with a macro), then we could use pr_err_once/ratelimited and
print 1 line with error and caller function.

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [syzbot] WARNING in bpf_warn_invalid_xdp_action
       [not found] <000000000000a16ad7059cbcbe43@google.com>
  2020-01-22 21:01 ` WARNING in bpf_warn_invalid_xdp_action syzbot
@ 2022-02-10  9:29 ` syzbot
  2022-02-16 15:33   ` Dmitry Vyukov
  1 sibling, 1 reply; 5+ messages in thread
From: syzbot @ 2022-02-10  9:29 UTC (permalink / raw)
  To: andrii, andriin, ast, bpf, corbet, daniel, davem, dsahern,
	dvyukov, eric.dumazet, hawk, john.fastabend, kafai, kpsingh, kuba,
	linux-doc, linux-kernel, netdev, pabeni, songliubraving,
	syzkaller-bugs, toke, yhs

syzbot suspects this issue was fixed by commit:

commit 2cbad989033bff0256675c38f96f5faab852af4b
Author: Paolo Abeni <pabeni@redhat.com>
Date:   Tue Nov 30 10:08:06 2021 +0000

    bpf: Do not WARN in bpf_warn_invalid_xdp_action()

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10d50baa700000
start commit:   b3c8e0de473e Merge branch '40GbE' of git://git.kernel.org/..
git tree:       net
kernel config:  https://syzkaller.appspot.com/x/.config?x=1a86c22260afac2f
dashboard link: https://syzkaller.appspot.com/bug?extid=8ce4113dadc4789fac74
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=113c8a3bb00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16eb4307b00000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: bpf: Do not WARN in bpf_warn_invalid_xdp_action()

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [syzbot] WARNING in bpf_warn_invalid_xdp_action
  2022-02-10  9:29 ` [syzbot] " syzbot
@ 2022-02-16 15:33   ` Dmitry Vyukov
  0 siblings, 0 replies; 5+ messages in thread
From: Dmitry Vyukov @ 2022-02-16 15:33 UTC (permalink / raw)
  To: syzbot
  Cc: andrii, andriin, ast, bpf, corbet, daniel, davem, dsahern,
	eric.dumazet, hawk, john.fastabend, kafai, kpsingh, kuba,
	linux-doc, linux-kernel, netdev, pabeni, songliubraving,
	syzkaller-bugs, toke, yhs

On Thu, 10 Feb 2022 at 10:29, syzbot
<syzbot+8ce4113dadc4789fac74@syzkaller.appspotmail.com> wrote:
>
> syzbot suspects this issue was fixed by commit:
>
> commit 2cbad989033bff0256675c38f96f5faab852af4b
> Author: Paolo Abeni <pabeni@redhat.com>
> Date:   Tue Nov 30 10:08:06 2021 +0000
>
>     bpf: Do not WARN in bpf_warn_invalid_xdp_action()
>
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10d50baa700000
> start commit:   b3c8e0de473e Merge branch '40GbE' of git://git.kernel.org/..
> git tree:       net
> kernel config:  https://syzkaller.appspot.com/x/.config?x=1a86c22260afac2f
> dashboard link: https://syzkaller.appspot.com/bug?extid=8ce4113dadc4789fac74
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=113c8a3bb00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16eb4307b00000
>
> If the result looks correct, please mark the issue as fixed by replying with:
>
> #syz fix: bpf: Do not WARN in bpf_warn_invalid_xdp_action()

Looks legit:

#syz fix: bpf: Do not WARN in bpf_warn_invalid_xdp_action()

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2022-02-16 15:33 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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     [not found] <000000000000a16ad7059cbcbe43@google.com>
2020-01-22 21:01 ` WARNING in bpf_warn_invalid_xdp_action syzbot
2020-01-22 21:38   ` Eric Dumazet
2020-01-23  6:19     ` Dmitry Vyukov
2022-02-10  9:29 ` [syzbot] " syzbot
2022-02-16 15:33   ` Dmitry Vyukov

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