From mboxrd@z Thu Jan 1 00:00:00 1970 From: dingtianhong Subject: [PATCH] net: add checks if dev->netdev_ops is NULL in register_netdevice() Date: Mon, 8 Apr 2013 17:43:53 +0800 Message-ID: <51629159.9040000@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit To: "David S. Miller" , Eric Dumazet , Alexander Duyck , Netdev , Li Zefan , Xinwei Hu Return-path: Received: from szxga02-in.huawei.com ([119.145.14.65]:61845 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761729Ab3DHJoS (ORCPT ); Mon, 8 Apr 2013 05:44:18 -0400 Sender: netdev-owner@vger.kernel.org List-ID: In some cases netdev->netdev_ops could be NULL in the register_netdevice(), thus a NULL point deference happens and lead to oops: [ 8260.836400] BUG: unable to handle kernel NULL pointer dereference at (null) [ 8260.955306] IP: [] register_netdevice+0x73/0x2d0 [ 8261.054888] PGD 2f4dcd067 PUD 2f4de0067 PMD 0 [ 8261.134244] Oops: 0000 [#1] SMP [ 8261.198938] CPU 0 [ 8262.605182] RIP: 0010:[] [] register_netdevice+0x73/0x2d0 [ 8262.741859] RSP: 0018:ffff8802f489f9f8 EFLAGS: 00010246 [ 8262.839463] RAX: 0000000000000000 RBX: ffff8802f4e73000 RCX: ffff8802f4e73006 [ 8262.959484] RDX: 0000000000000000 RSI: 00000000daa92527 RDI: ffff8802f4e73006 [ 8263.079352] RBP: 0000000000000000 R08: 0000000000000000 R09: ffff880327d898c0 [ 8263.198987] R10: 00000000000000c1 R11: 0000000000000000 R12: ffffffff81fed080 [ 8263.318401] R13: ffffffff81fed080 R14: ffff8802f4e73000 R15: 0000000000000000 [ 8263.438014] FS: 00007f01dfa81700(0000) GS:ffff88033f200000(0000) knlGS:0000000000000000 [ 8263.569778] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8263.673859] CR2: 0000000000000000 CR3: 000000032893f000 CR4: 00000000000006f0 [ 8263.794922] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 8263.915734] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 8264.036251] Process rmcli (pid: 14089, threadinfo ffff8802f489e000, task ffff880324708080) [ 8264.170961] Stack: [ 8264.231328] ffff88032a3c0000 0000000000000003 0000000000000003 ffff88032a3c0000 [ 8264.356967] 0000000000000003 ffffffffa039dbcb 000000003ec216c0 0000000000000246 [ 8264.483081] 382e30363238205b 00205d3900000006 ff00305f63696e76 0000000000000003 We should check the point to avoid the oops. Signed-off-by: Ding Tianhong --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/dev.c b/net/core/dev.c index e7d68ed..596a11e 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5159,7 +5159,7 @@ int register_netdevice(struct net_device *dev) goto out; /* Init, if this function is available */ - if (dev->netdev_ops->ndo_init) { + if (dev->netdev_ops && dev->netdev_ops->ndo_init) { ret = dev->netdev_ops->ndo_init(dev); if (ret) { if (ret > 0) -- 1.8.0