Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752307AbdGWJ7k (ORCPT ); Sun, 23 Jul 2017 05:59:40 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:10334 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751332AbdGWJ7j (ORCPT ); Sun, 23 Jul 2017 05:59:39 -0400 From: "liujian (CE)" To: "liujian (CE)" , Cong Wang , Dingtianhong CC: Willem de Bruijn , Dave Jones , "alexander.levin@verizon.com" , "davem@davemloft.net" , "edumazet@google.com" , "willemb@google.com" , "daniel@iogearbox.net" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: RE: af_packet: use after free in prb_retire_rx_blk_timer_expired Thread-Topic: af_packet: use after free in prb_retire_rx_blk_timer_expired Thread-Index: AQHSsi0kPKd7RxFbFUioT9017kTPL6G+dU+AgAHVPYCAn++J8IAAFXSAgACQ+ICAACagAIAArApggAAUuoA= Date: Sun, 23 Jul 2017 09:47:20 +0000 Message-ID: <4F88C5DDA1E80143B232E89585ACE27D018CB6A9@DGGEMA502-MBS.china.huawei.com> References: <20170410190350.ngfw435zzr7gpw7e@sasha-lappy> <20170410192309.35x7ddya2cyyv4y6@codemonkey.org.uk> <4F88C5DDA1E80143B232E89585ACE27D018C33F1@DGGEMA502-MBX.china.huawei.com>

Accept-Language: en-US Content-Language: zh-CN X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.177.97.126] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A0B0201.59747133.0034,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=169.254.3.238, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 0d2cec786f35fe6a627eed55fbff1e34 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id v6N9xmYp009353 Content-Length: 4860 Lines: 117 Hi, Do we need delete the v3 ring, when tp_version changed from TPACKET_V3 to TPACKET_V1 ? Best Regards, liujian > -----Original Message----- > From: liujian (CE) > Sent: Sunday, July 23, 2017 4:21 PM > To: 'Cong Wang'; Dingtianhong > Cc: Willem de Bruijn; Dave Jones; alexander.levin@verizon.com; > davem@davemloft.net; edumazet@google.com; willemb@google.com; > daniel@iogearbox.net; netdev@vger.kernel.org; linux-kernel@vger.kernel.org > Subject: RE: af_packet: use after free in prb_retire_rx_blk_timer_expired > > Hi Wang Cong, > > With this patch , the system was crashed when setsockopt. > > The call trace as below: > > crash> bt > PID: 3069 TASK: ffff8800afcc0000 CPU: 0 COMMAND: "trinity-main" > #0 [ffff8801bec03ce0] machine_kexec at ffffffff8105354b > #1 [ffff8801bec03d40] crash_kexec at ffffffff810f7e82 > #2 [ffff8801bec03e10] panic at ffffffff81650058 > #3 [ffff8801bec03e90] watchdog_timer_fn at ffffffff81122533 > #4 [ffff8801bec03ec8] __hrtimer_run_queues at ffffffff810abeb2 > #5 [ffff8801bec03f20] hrtimer_interrupt at ffffffff810ac450 > #6 [ffff8801bec03f70] local_apic_timer_interrupt at ffffffff8104a457 > #7 [ffff8801bec03f88] smp_apic_timer_interrupt at ffffffff8166aed0 > #8 [ffff8801bec03fb0] apic_timer_interrupt at ffffffff8166931d > --- --- > #9 [ffff8801b301fcb8] apic_timer_interrupt at ffffffff8166931d > [exception RIP: lock_timer_base+77] > RIP: ffffffff8108dced RSP: ffff8801b301fd60 RFLAGS: 00000246 > RAX: 0000000000000000 RBX: ffff8800afcc0000 RCX: > 0000000000000001 > RDX: ffff8800afcc0000 RSI: ffff8801b301fd90 RDI: ffff8800b0d853c8 > RBP: ffff8801b301fd80 R8: ffff8800afcc0000 R9: ffffea0002680000 > R10: 000000000000003c R11: ffff8801b301fb2e R12: ffff8800afcc0000 > R13: ffff8800afcc0000 R14: 0000000000000000 R15: ffffffff83d1a340 > ORIG_RAX: ffffffffffffff10 CS: 0010 SS: 0018 > #10 [ffff8801b301fd88] try_to_del_timer_sync at ffffffff8108f19f > #11 [ffff8801b301fdb8] del_timer_sync at ffffffff8108f252 > #12 [ffff8801b301fdd0] packet_set_ring at ffffffff81635e60 > #13 [ffff8801b301fe98] packet_setsockopt at ffffffff81636760 > #14 [ffff8801b301ff38] sys_setsockopt at ffffffff81531860 > #15 [ffff8801b301ff80] tracesys at ffffffff816687ed (via system_call) > RIP: 00007fcc78b03e3a RSP: 00007fff16f246b8 RFLAGS: 00000202 > RAX: ffffffffffffffda RBX: ffffffff816687ed RCX: ffffffffffffffff > RDX: 0000000000000005 RSI: 0000000000000107 RDI: > 0000000000000180 > RBP: 0000000000000180 R8: 000000000000001c R9: > 00007fcc78dc7160 > R10: 0000000001fd6ba0 R11: 0000000000000202 R12: > 0000000000000000 > R13: 0000000000000011 R14: 0000000001fd6b60 R15: > 0000000001fd6b70 > ORIG_RAX: 0000000000000036 CS: 0033 SS: 002b > > > Best Regards, > liujian > > > > -----Original Message----- > > From: Cong Wang [mailto:xiyou.wangcong@gmail.com] > > Sent: Sunday, July 23, 2017 1:59 PM > > To: Dingtianhong > > Cc: liujian (CE); Willem de Bruijn; Dave Jones; > > alexander.levin@verizon.com; davem@davemloft.net; > edumazet@google.com; > > willemb@google.com; daniel@iogearbox.net; netdev@vger.kernel.org; > > linux-kernel@vger.kernel.org > > Subject: Re: af_packet: use after free in > > prb_retire_rx_blk_timer_expired > > > > On Sat, Jul 22, 2017 at 8:40 PM, Ding Tianhong > > > > wrote: > > > Hi, Cong: > > > > > > Thanks for your quirk solution, but I still has some doubts about > > > it, it looks like fix the problem in the > > > packet_setsockopt->packet_set_ring processing, but when in > > > packet_release processing, it may could not release the real pg_vec > > > for the TPACKET_V3 ring, and then cause the mem leak, maybe I miss > > > something here, nice to hear from your feedback. :) > > > > Yes you miss that packet_release() has memset()'s so we won't hit that > > path. :) > > > > However, I missed the swap() in this messy function, actually I > > believe the bug is that we modify tpacket_kbdq_core inside rx_ring in > > non-closing case without actually stopping its timer. I feel more confident > with the following patch: > > > > > > diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index > > 008bb34ee324..267b181fef15 100644 > > --- a/net/packet/af_packet.c > > +++ b/net/packet/af_packet.c > > @@ -4263,6 +4263,7 @@ static int packet_set_ring(struct sock *sk, > > union tpacket_req_u *req_u, > > case TPACKET_V3: > > /* Block transmit is not supported yet */ > > if (!tx_ring) { > > + prb_shutdown_retire_blk_timer(po, > > + rb_queue); > > init_prb_bdqc(po, rb, pg_vec, req_u); > > } else { > > struct tpacket_req3 *req3 = > > &req_u->req3;