From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1836022256F; Wed, 9 Jul 2025 18:56:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752087390; cv=none; b=MIZWqHVKclSwZ+h7fk8nC70a3oaAc738W3mT6L5FKLID+pRM/ESiG+/jLqvPbMCUssdBn18G/CrZAR3vYtRDPokioIBJ8bZGXRjvvAblGtdp5l+Dy5/xkynsZHHNmRQw3neIb3c9AAFb078bImNPEo8vLEgAp47BdT6vEChaiTA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752087390; c=relaxed/simple; bh=U2ym3y03dOWKJNhcj1ySueQzgVlsYFO3xy7ENC+WF2M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=K7ovRXHBTbvngpVM0A84uhWuHT/aB0EPjnfxCEUUpo18TRagh21+kLNaChlrOw/FuB+8YLeJ9bCFS9Gf2o+yMk80n8Gqhuy7JvoNq5MwlYKgJ4PEvEfaYtIqtfyo+hJ9b5XvAvn91UNPHanEWXt3YLTXUOXMGpwGJ8quOkKpEnU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ba8fU/qK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ba8fU/qK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0ECF9C4CEEF; Wed, 9 Jul 2025 18:56:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752087389; bh=U2ym3y03dOWKJNhcj1ySueQzgVlsYFO3xy7ENC+WF2M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ba8fU/qK1STvM0PwmV/USglE/5Fis0nZN/esbL7Q3i8qfdOUZ2v0sPaSnxHDmaUso C7PnBabk6300KGb9JYrXtzQbXTXJJSffPtBrk0XIjbgWU+aY1RB5bdh6NamC19fM8z HhoGW7JZXDneDRYenG6p/NYw/Kflm9d8eZzwfV4Fx2plCiXiCtz6BBodKUmLyuP9eb XupPnQolMyElAt0vy2ODMNTNsMo8kRz7Hi/RLcsjh1hujxS0G9a1ivnYjV8EreL77w v31o3Zuy3pmlJitFtCk6pmbJ3krn+BY3LQdBEiiE12AlnM+FSb6GmYtgJqAmQvrOqs sBnfEuDbuRFXA== Date: Wed, 9 Jul 2025 19:56:26 +0100 From: Simon Horman To: Yue Haibing Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Kuniyuki Iwashima Subject: Re: [PATCH v2 net] atm: clip: Fix NULL pointer dereference in vcc_sendmsg() Message-ID: <20250709185626.GN721198@horms.kernel.org> References: <20250705085228.329202-1-yuehaibing@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250705085228.329202-1-yuehaibing@huawei.com> + Iwashima-san On Sat, Jul 05, 2025 at 04:52:28PM +0800, Yue Haibing wrote: > atmarpd_dev_ops does not implement the send method, which may cause crash > as bellow. > > BUG: kernel NULL pointer dereference, address: 0000000000000000 > PGD 0 P4D 0 > Oops: Oops: 0010 [#1] SMP KASAN NOPTI > CPU: 0 UID: 0 PID: 5324 Comm: syz.0.0 Not tainted 6.15.0-rc6-syzkaller-00346-g5723cc3450bc #0 PREEMPT(full) > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 > RIP: 0010:0x0 > Code: Unable to access opcode bytes at 0xffffffffffffffd6. > RSP: 0018:ffffc9000d3cf778 EFLAGS: 00010246 > RAX: 1ffffffff1910dd1 RBX: 00000000000000c0 RCX: dffffc0000000000 > RDX: ffffc9000dc82000 RSI: ffff88803e4c4640 RDI: ffff888052cd0000 > RBP: ffffc9000d3cf8d0 R08: ffff888052c9143f R09: 1ffff1100a592287 > R10: dffffc0000000000 R11: 0000000000000000 R12: 1ffff92001a79f00 > R13: ffff888052cd0000 R14: ffff88803e4c4640 R15: ffffffff8c886e88 > FS: 00007fbc762566c0(0000) GS:ffff88808d6c2000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffffffffffd6 CR3: 0000000041f1b000 CR4: 0000000000352ef0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > > vcc_sendmsg+0xa10/0xc50 net/atm/common.c:644 > sock_sendmsg_nosec net/socket.c:712 [inline] > __sock_sendmsg+0x219/0x270 net/socket.c:727 > ____sys_sendmsg+0x52d/0x830 net/socket.c:2566 > ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620 > __sys_sendmmsg+0x227/0x430 net/socket.c:2709 > __do_sys_sendmmsg net/socket.c:2736 [inline] > __se_sys_sendmmsg net/socket.c:2733 [inline] > __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2733 > do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] > do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Reported-by: syzbot+e34e5e6b5eddb0014def@syzkaller.appspotmail.com > Closes: https://lore.kernel.org/all/682f82d5.a70a0220.1765ec.0143.GAE@google.com/T > Signed-off-by: Yue Haibing > --- > v2: Add atm_return_tx() call > --- > net/atm/clip.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/net/atm/clip.c b/net/atm/clip.c > index b234dc3bcb0d..170f9386d42d 100644 > --- a/net/atm/clip.c > +++ b/net/atm/clip.c > @@ -616,8 +616,16 @@ static void atmarpd_close(struct atm_vcc *vcc) > module_put(THIS_MODULE); > } > > +static int atmarpd_send(struct atm_vcc *vcc, struct sk_buff *skb) > +{ > + atm_return_tx(vcc, skb); > + dev_kfree_skb_any(skb); > + return 0; > +} > + > static const struct atmdev_ops atmarpd_dev_ops = { > - .close = atmarpd_close > + .close = atmarpd_close, > + .send = atmarpd_send > }; > > > -- > 2.34.1 >