Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757351Ab1DYIHi (ORCPT ); Mon, 25 Apr 2011 04:07:38 -0400 Received: from mail-ww0-f44.google.com ([74.125.82.44]:54817 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751242Ab1DYIHh (ORCPT ); Mon, 25 Apr 2011 04:07:37 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=yEorih6QJ6W02Xh2J5G6HBvTr5ZMaxNBu9Id8w/fj+sCO6ZNFZSwmF8kwi5N/0W75+ RpWV19WewfvvrVVWaXGIaIpKZPgTM8bP9MpEJQde+MFdobQ2vBW2JgEuuRJGxH7rvCoW wIURiW+cOYP/S9FyjvNcrfGwHZZbdd5UaUrmE= Subject: Re: Oops in 2.6.39 include/net/dst.h: dst_metrics_write_ptr() running l2tp over ipsec From: Eric Dumazet To: Held Bernhard Cc: linux-kernel@vger.kernel.org, "David S. Miller" , netdev@vger.kernel.org In-Reply-To: <4DB4A619.9080600@gmx.de> References: <4DB4A619.9080600@gmx.de> Content-Type: text/plain; charset="UTF-8" Date: Mon, 25 Apr 2011 10:07:32 +0200 Message-ID: <1303718852.2747.103.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6973 Lines: 175 From: Held Bernhard Le lundi 25 avril 2011 à 00:37 +0200, Held Bernhard a écrit : > Hi, > > I'm starting l2tp over ipsec (racoon, openl2tp) in a little script to > establish a VPN to my company. 2.6.38.x runs fine, but since 2.6.39-rc1 > (exactly commit 62fa8a "net: Implement read-only protection and COW'ing > of metrics.") the kernel throws an oops. openl2tp is killed; after a 2nd > start of openl2tp the VPN is established and my PC continues to run > normally. The oops is 100% reproducible. ... > Please tell me if you need more information! > > Thanks, > Bernhard > - Thanks for your report and patch. Maybe following patch is the way to fix this, please test it. [PATCH] net: provide cow_metrics() methods to blackhole dst_ops Since commit 62fa8a846d7d (net: Implement read-only protection and COW'ing of metrics.) the kernel throws an oops. [ 101.620985] BUG: unable to handle kernel NULL pointer dereference at (null) [ 101.621050] IP: [< (null)>] (null) [ 101.621084] PGD 6e53c067 PUD 3dd6a067 PMD 0 [ 101.621122] Oops: 0010 [#1] SMP [ 101.621153] last sysfs file: /sys/devices/virtual/ppp/ppp/uevent [ 101.621192] CPU 2 [ 101.621206] Modules linked in: l2tp_ppp pppox ppp_generic slhc l2tp_netlink l2tp_core deflate zlib_deflate twofish_x86_64 twofish_common des_generic cbc ecb sha1_generic hmac af_key iptable_filter snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device loop snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_pcm snd_timer snd i2c_i801 iTCO_wdt psmouse soundcore snd_page_alloc evdev uhci_hcd ehci_hcd thermal [ 101.621552] [ 101.621567] Pid: 5129, comm: openl2tpd Not tainted 2.6.39-rc4-Quad #3 Gigabyte Technology Co., Ltd. G33-DS3R/G33-DS3R [ 101.621637] RIP: 0010:[<0000000000000000>] [< (null)>] (null) [ 101.621684] RSP: 0018:ffff88003ddeba60 EFLAGS: 00010202 [ 101.621716] RAX: ffff88003ddb5600 RBX: ffff88003ddb5600 RCX: 0000000000000020 [ 101.621758] RDX: ffffffff81a69a00 RSI: ffffffff81b7ee61 RDI: ffff88003ddb5600 [ 101.621800] RBP: ffff8800537cd900 R08: 0000000000000000 R09: ffff88003ddb5600 [ 101.621840] R10: 0000000000000005 R11: 0000000000014b38 R12: ffff88003ddb5600 [ 101.621881] R13: ffffffff81b7e480 R14: ffffffff81b7e8b8 R15: ffff88003ddebad8 [ 101.621924] FS: 00007f06e4182700(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000 [ 101.621971] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 101.622005] CR2: 0000000000000000 CR3: 0000000045274000 CR4: 00000000000006e0 [ 101.622046] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 101.622087] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 101.622129] Process openl2tpd (pid: 5129, threadinfo ffff88003ddea000, task ffff88003de9a280) [ 101.622177] Stack: [ 101.622191] ffffffff81447efa ffff88007d3ded80 ffff88003de9a280 ffff88007d3ded80 [ 101.622245] 0000000000000001 ffff88003ddebbb8 ffffffff8148d5a7 0000000000000212 [ 101.622299] ffff88003dcea000 ffff88003dcea188 ffffffff00000001 ffffffff81b7e480 [ 101.622353] Call Trace: [ 101.622374] [] ? ipv4_blackhole_route+0x1ba/0x210 [ 101.622415] [] ? xfrm_lookup+0x417/0x510 [ 101.622450] [] ? extract_buf+0x9a/0x140 [ 101.622485] [] ? __ip_flush_pending_frames+0x70/0x70 [ 101.622526] [] ? udp_sendmsg+0x62f/0x810 [ 101.622562] [] ? sock_sendmsg+0x116/0x130 [ 101.622599] [] ? find_get_page+0x18/0x90 [ 101.622633] [] ? filemap_fault+0x12a/0x4b0 [ 101.622668] [] ? move_addr_to_kernel+0x64/0x90 [ 101.622706] [] ? verify_iovec+0x7a/0xf0 [ 101.622739] [] ? sys_sendmsg+0x292/0x420 [ 101.622774] [] ? handle_pte_fault+0x8a/0x7c0 [ 101.622810] [] ? __pte_alloc+0xae/0x130 [ 101.622844] [] ? handle_mm_fault+0x138/0x380 [ 101.622880] [] ? do_page_fault+0x189/0x410 [ 101.622915] [] ? sys_getsockname+0xf3/0x110 [ 101.622952] [] ? ip_setsockopt+0x4d/0xa0 [ 101.622986] [] ? sockfd_lookup_light+0x22/0x90 [ 101.623024] [] ? system_call_fastpath+0x16/0x1b [ 101.623060] Code: Bad RIP value. [ 101.623090] RIP [< (null)>] (null) [ 101.623125] RSP [ 101.623146] CR2: 0000000000000000 [ 101.650871] ---[ end trace ca3856a7d8e8dad4 ]--- [ 101.651011] __sk_free: optmem leakage (160 bytes) detected. The oops happens in dst_metrics_write_ptr() include/net/dst.h:124: return dst->ops->cow_metrics(dst, p); dst->ops->cow_metrics is NULL and causes the oops. Provide cow_metrics() methods, like we did in commit 214f45c91bb (net: provide default_advmss() methods to blackhole dst_ops) Signed-off-by: Held Bernhard Signed-off-by: Eric Dumazet --- net/ipv4/route.c | 7 +++++++ net/ipv6/route.c | 7 +++++++ 2 files changed, 14 insertions(+) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index c1acf69..99e6e4b 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2690,6 +2690,12 @@ static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu) { } +static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, + unsigned long old) +{ + return NULL; +} + static struct dst_ops ipv4_dst_blackhole_ops = { .family = AF_INET, .protocol = cpu_to_be16(ETH_P_IP), @@ -2698,6 +2704,7 @@ static struct dst_ops ipv4_dst_blackhole_ops = { .default_mtu = ipv4_blackhole_default_mtu, .default_advmss = ipv4_default_advmss, .update_pmtu = ipv4_rt_blackhole_update_pmtu, + .cow_metrics = ipv4_rt_blackhole_cow_metrics, }; struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 843406f..93b10e6 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -153,6 +153,12 @@ static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu) { } +static u32 *ip6_rt_blackhole_cow_metrics(struct dst_entry *dst, + unsigned long old) +{ + return NULL; +} + static struct dst_ops ip6_dst_blackhole_ops = { .family = AF_INET6, .protocol = cpu_to_be16(ETH_P_IPV6), @@ -161,6 +167,7 @@ static struct dst_ops ip6_dst_blackhole_ops = { .default_mtu = ip6_blackhole_default_mtu, .default_advmss = ip6_default_advmss, .update_pmtu = ip6_rt_blackhole_update_pmtu, + .cow_metrics = ip6_rt_blackhole_cow_metrics, }; static const u32 ip6_template_metrics[RTAX_MAX] = { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/