From nobody Tue Oct 7 21:41:59 2025 Received: from szxga06-in.huawei.com (szxga06-in.huawei.com [45.249.212.32]) (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 A60AD2E3702; Sat, 5 Jul 2025 08:31:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.32 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751704296; cv=none; b=bJSiS0W8PXadDMXktpC925RkmDNAC7UpN8RYYC7VhGwvKAhlzTQ9YNe3a9Fgpg+h9oScxsOJH8xXOlM2NIJmwAeqldr0CE6WRRkCJv3ERLwcABe9CCV+t2shXgPUCGIaXN0FhuvB66Tia2LRREg9EKrexyVYIluwFMwEFLUjbn0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751704296; c=relaxed/simple; bh=J0E8HN+m0lxf9U9PXWp7oYqn6/NzReP+6gkjAYV/Ycg=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=oEwQ62NfNpiM755fABOpZrTMmwxq/NuC32Noo4l8jU6VSmnXiYI62s35sEhK9nHTfilPAYh3SZu7BhRbW2+H0V+hLGfK2IN0PN0qGPylB9devwV8siMSa9ROmbIOlwFRXLBLLAz6VV7KoLx5VPtW4sKQwMVvlV0Bty5jNmsjZts= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.162.112]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4bZ3f34HZxz2qFB7; Sat, 5 Jul 2025 16:32:27 +0800 (CST) Received: from dggpemf500002.china.huawei.com (unknown [7.185.36.57]) by mail.maildlp.com (Postfix) with ESMTPS id A28861401F1; Sat, 5 Jul 2025 16:31:30 +0800 (CST) Received: from huawei.com (10.175.124.27) by dggpemf500002.china.huawei.com (7.185.36.57) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Sat, 5 Jul 2025 16:31:29 +0800 From: Yue Haibing To: , , , , CC: , , Subject: [PATCH v2 net] atm: clip: Fix NULL pointer dereference in vcc_sendmsg() Date: Sat, 5 Jul 2025 16:52:28 +0800 Message-ID: <20250705085228.329202-1-yuehaibing@huawei.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: kwepems200001.china.huawei.com (7.221.188.67) To dggpemf500002.china.huawei.com (7.185.36.57) Content-Type: text/plain; charset="utf-8" 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-0034= 6-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@googl= e.com/T Signed-off-by: Yue Haibing Reviewed-by: Kuniyuki Iwashima --- 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); } =20 +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 =3D { - .close =3D atmarpd_close + .close =3D atmarpd_close, + .send =3D atmarpd_send }; =20 =20 --=20 2.34.1