From: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
To: syzbot <syzbot+f534bd500d914e34b59e@syzkaller.appspotmail.com>
Cc: andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org,
daniel@iogearbox.net, davem@davemloft.net, edumazet@google.com,
hawk@kernel.org, john.fastabend@gmail.com, kuba@kernel.org,
linux-kernel@vger.kernel.org, lorenzo@kernel.org,
netdev@vger.kernel.org, pabeni@redhat.com,
syzkaller-bugs@googlegroups.com, toke@redhat.com
Subject: Re: [syzbot] [bpf?] [net?] WARNING in __xdp_reg_mem_model
Date: Mon, 6 May 2024 16:49:40 +0200 [thread overview]
Message-ID: <ZjjuBCk33QtxLrAm@lore-desk> (raw)
In-Reply-To: <000000000000ae301f0617a4a52c@google.com>
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> syzbot has bisected this issue to:
>
> commit 2b0cfa6e49566c8fa6759734cf821aa6e8271a9e
> Author: Lorenzo Bianconi <lorenzo@kernel.org>
> Date: Mon Feb 12 09:50:54 2024 +0000
>
> net: add generic percpu page_pool allocator
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=151860d4980000
> start commit: f99c5f563c17 Merge tag 'nf-24-03-21' of git://git.kernel.o..
> git tree: net
> final oops: https://syzkaller.appspot.com/x/report.txt?x=171860d4980000
> console output: https://syzkaller.appspot.com/x/log.txt?x=131860d4980000
> kernel config: https://syzkaller.appspot.com/x/.config?x=6fb1be60a193d440
> dashboard link: https://syzkaller.appspot.com/bug?extid=f534bd500d914e34b59e
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17ac600b180000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1144b797180000
>
> Reported-by: syzbot+f534bd500d914e34b59e@syzkaller.appspotmail.com
> Fixes: 2b0cfa6e4956 ("net: add generic percpu page_pool allocator")
>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
>
Looking at the code, the root cause of the issue is the WARN(1) in
__xdp_reg_mem_model routine. __mem_id_init_hash_table() can fail just if rht
allocation fails. Do we really need this WARN(1)? It has been introduced in the
commit below:
commit 8d5d88527587516bd58ff0f3810f07c38e65e2be
Author: Jesper Dangaard Brouer <brouer@redhat.com>
Date: Tue Apr 17 16:46:12 2018 +0200
xdp: rhashtable with allocator ID to pointer mapping
Regards,
Lorenzo
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prev parent reply other threads:[~2024-05-06 14:49 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-17 9:15 [syzbot] [bpf?] [net?] WARNING in __xdp_reg_mem_model syzbot
2024-05-04 18:03 ` syzbot
2024-05-06 14:49 ` Lorenzo Bianconi [this message]
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