From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751528AbcGRCU1 (ORCPT ); Sun, 17 Jul 2016 22:20:27 -0400 Received: from mail-qk0-f195.google.com ([209.85.220.195]:33630 "EHLO mail-qk0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750931AbcGRCUY convert rfc822-to-8bit (ORCPT ); Sun, 17 Jul 2016 22:20:24 -0400 MIME-Version: 1.0 In-Reply-To: References: <20160711221544.42291-1-li.feng@oracle.com>

From: Feng Li Date: Mon, 18 Jul 2016 10:19:54 +0800 Message-ID: Subject: Re: [PATCH] iscsi-target: fix panic when add the second TCP connection to iSCSI session To: Sumit Rai Cc: "nab@linux-iscsi.org" , agrover@redhat.com, "varun@chelsio.com" , Herbert Xu , Roland Dreier , Zhu Lingshan , "linux-scsi@vger.kernel.org" , target-devel@vger.kernel.org, linux-kernel Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Sumit, I have tested and the oops is disappeared. Could you double check if you have patched successfully? This stack is still the same. The place is 0x00000000000001f8. gdb> p (int)&((struct iscsi_session*)0)->se_sess $3 = 0x1f8 2016-07-14 17:59 GMT+08:00 Sumit Rai : > Thanks for the patch Feng, I have tested this patch and below panic has also disappeared. > (initially reported at http://article.gmane.org/gmane.linux.scsi.target.devel/12735). > > dmesg > ===== > [ 862.784477] BUG: unable to handle kernel NULL pointer dereference at 00000000000001f8 > [ 862.784486] IP: [] iscsi_target_login_thread+0x724/0xfa0 [iscsi_target_mod] > [ 862.784570] PGD 0 > [ 862.784572] Oops: 0000 [#1] SMP > [ 862.784575] Modules linked in: target_core_user uio tcm_fc libfc ib_srpt tcm_usb_gadget > libcomposite udc_core tcm_loop vhost_scsi vhost iscsi_target_mod tcm_qla2xxx qla2xxx > scsi_transport_fc target_core_file target_core_iblock target_core_pscsi target_core_mod > configfs pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) > vmw_vsock_vmci_transport vsock vmhgfs(OE) coretemp kvm_intel kvm binfmt_misc irqbypass > crct10dif_pclmul crc32_pclmul aesni_intel vmw_balloon aes_x86_64 lrw gf128mul glue_helper > ablk_helper cryptd joydev input_leds serio_raw i2c_piix4 vmw_vmci shpchp 8250_fintek mac_hid > ib_iser rdma_cm iw_cm ib_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi_tcp libiscsi > scsi_transport_iscsi parport_pc ppdev lp parport autofs4 hid_generic usbhid hid vmwgfx ttm psmouse > drm_kms_helper syscopyarea > [ 862.784609] sysfillrect sysimgblt mptspi mptscsih fb_sys_fops drm ahci libahci e1000 mptbase > scsi_transport_spi pata_acpi floppy fjes > [ 862.784618] CPU: 0 PID: 9241 Comm: iscsi_np Tainted: G OE 4.4.0-24-generic #43-Ubuntu > [ 862.784620] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, > BIOS 6.00 05/20/2014 > [ 862.784622] task: ffff8800759d1b80 ti: ffff880075a00000 task.ti: ffff880075a00000 > [ 862.784624] RIP: 0010:[] [] > iscsi_target_login_thread+0x724/0xfa0 [iscsi_target_mod] > [ 862.784632] RSP: 0018:ffff880075a03e40 EFLAGS: 00010246 > [ 862.784633] RAX: 0000000000000000 RBX: ffff880075a52800 RCX: 0000000000037726 > [ 862.784635] RDX: 0000000000037725 RSI: ffff88007b619fe0 RDI: ffff880033bce800 > [ 862.784636] RBP: ffff880075a03ec0 R08: 0000000000019fe0 R09: ffffffffc06067c6 > [ 862.784637] R10: ffffea0001d1d880 R11: 654d687475410032 R12: ffff880074763140 > [ 862.784638] R13: ffff880075a52820 R14: ffff880075a528d8 R15: ffff880033bce800 > [ 862.784640] FS: 0000000000000000(0000) GS:ffff88007b600000(0000) knlGS:0000000000000000 > [ 862.784641] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 862.784642] CR2: 00000000000001f8 CR3: 0000000072f8e000 CR4: 00000000000406f0 > [ 862.784716] Stack: > [ 862.784719] ffff880075e87080 ffff88003526f358 ffff8800799cc420 ffff880000000000 > [ 862.784721] ffff880079cd0100 ffff880075a52828 00ff88003526ee00 ffff880075a528d8 > [ 862.784723] ffff8800759d1b80 ffff880075a52800 0000000058f0fa77 ffff880075a0aac0 > [ 862.784725] Call Trace: > [ 862.784736] [] ? iscsi_target_login_sess_out+0x240/0x240 [iscsi_target_mod] > [ 862.784782] [] kthread+0xd8/0xf0 > [ 862.784786] [] ? kthread_create_on_node+0x1e0/0x1e0 > [ 862.784789] [] ret_from_fork+0x3f/0x70 > [ 862.784791] [] ? kthread_create_on_node+0x1e0/0x1e0 > [ 862.784792] Code: 00 00 4c 89 e2 4c 89 fe 48 89 df e8 c7 19 00 00 85 c0 0f 88 32 01 00 00 0f b6 45 b7 4c 89 ff 41 88 44 24 09 > 49 8b 87 48 05 00 00 <4c> 8b b0 f8 01 00 00 49 8b 87 10 05 00 00 ff 90 98 00 00 00 41 > [ 862.784811] RIP [] iscsi_target_login_thread+0x724/0xfa0 [iscsi_target_mod] > [ 862.784819] RSP > [ 862.784820] CR2: 00000000000001f8 > [ 862.784823] ---[ end trace 7e41630f165c8027 ]--- > > Regards, > Sumit Rai >> On Jul 12, 2016, at 8:46 AM, Feng Li wrote: >> >> Add lszhu@suse.com >> >> 2016-07-11 22:23 GMT+08:00 冯力 : >>> This problem exists at least from v3.16. >>> The upstream kernel still exists this issue. >>> >>> I have tested my patch and the following panic is disappeared. >>> >>> Thanks, >>> - Alex >>> >>> #dmesg >>> >>> [ 1160.788676] sd 16:0:0:0: [sde] Attached SCSI disk >>> [ 1383.962626] target_core_get_fabric() failed for usb_gadget >>> [ 1404.788910] TARGET_CORE[iSCSI]: Unsupported SCSI Opcode 0x1b, >>> sending CHECK_CONDITION. >>> [ 1404.858451] BUG: unable to handle kernel NULL pointer dereference >>> at 00000000000001f8 >>> [ 1404.858911] IP: [] >>> iscsi_target_login_thread+0x728/0x10b0 [iscsi_target_mod] >>> [ 1404.859746] PGD 230c29067 PUD 232060067 PMD 0 >>> [ 1404.859963] Oops: 0000 [#1] SMP >>> [ 1404.860154] Modules linked in: crc32c_generic tcm_loop tcm_qla2xxx >>> qla2xxx iscsi_target_mod ib_srpt vhost_scsi vhost tcm_fc libfc >>> scsi_transport_fc scsi_tgt target_core_file target_core_iblock >>> target_core_pscsi target_core_mod configfs nbd >>> vmw_vsock_vmci_transport vsock bridge stp llc vmhgfs(O) snd_ens1371 >>> snd_rawmidi snd_seq_device snd_ac97_codec snd_pcm snd_timer snd >>> vmw_balloon evdev soundcore ac97_bus gameport ppdev pcspkr sg psmouse >>> serio_raw parport_pc vmwgfx parport battery ttm drm_kms_helper drm >>> i2c_piix4 shpchp i2c_core vmw_vmci processor thermal_sys ac button >>> binfmt_misc md_mod ib_iser rdma_cm iw_cm ib_cm ib_sa ib_mad ib_core >>> ib_addr iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi >>> hid_generic usbhid hid ext4 crc16 mbcache jbd2 sd_mod crc_t10dif >>> crct10dif_generic crct10dif_common ata_generic >>> [ 1404.861278] mptspi scsi_transport_spi mptscsih ata_piix uhci_hcd >>> ehci_pci ehci_hcd mptbase libata usbcore e1000 usb_common scsi_mod >>> sunrpc dm_mirror dm_region_hash dm_log dm_mod autofs4 >>> [ 1404.861742] CPU: 2 PID: 1865 Comm: iscsi_np Tainted: G O >>> 3.16.0-4-amd64 #1 Debian 3.16.7-ckt25-1 >>> [ 1404.861868] Hardware name: VMware, Inc. VMware Virtual >>> Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015 >>> [ 1404.862033] task: ffff880234c849a0 ti: ffff8800b9c20000 task.ti: >>> ffff8800b9c20000 >>> [ 1404.862114] RIP: 0010:[] [] >>> iscsi_target_login_thread+0x728/0x10b0 [iscsi_target_mod] >>> [ 1404.862233] RSP: 0018:ffff8800b9c23e60 EFLAGS: 00010246 >>> [ 1404.862282] RAX: 0000000000000000 RBX: ffff88023125b800 RCX: ffff8802b4d8d000 >>> [ 1404.862344] RDX: 000000000000002d RSI: 00000000fffffe01 RDI: ffff880233ef1800 >>> [ 1404.862406] RBP: ffff8800b9651a00 R08: 00000000d5a073de R09: ffff88023487e6c0 >>> [ 1404.862585] R10: 00000000ead0c2e5 R11: 00000000d039ef6a R12: ffff88023125b854 >>> [ 1404.865580] R13: ffff88023125b908 R14: ffff880233ef1800 R15: ffff880234c849a0 >>> [ 1404.867732] FS: 00007fba67e2fb80(0000) GS:ffff88023e640000(0000) >>> knlGS:0000000000000000 >>> [ 1404.869772] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b >>> [ 1404.871850] CR2: 00000000000001f8 CR3: 0000000230ffa000 CR4: 00000000000007e0 >>> [ 1404.874271] Stack: >>> [ 1404.877492] ffff88023125b908 00ff880234c849a0 ffff88023125b858 >>> ffff88023481f400 >>> [ 1404.880162] ffffffff81510d00 ffff880230768000 ffff8800b9c23fd8 >>> 0000000000012f00 >>> [ 1404.883545] ffff880234c849a0 ffff880233e9da40 ffff88023125b800 >>> ffffffffa05edeb0 >>> [ 1404.885865] Call Trace: >>> [ 1404.888384] [] ? __schedule+0x250/0x700 >>> [ 1404.890619] [] ? >>> iscsi_target_login_sess_out+0x240/0x240 [iscsi_target_mod] >>> [ 1404.892668] [] ? kthread+0xbd/0xe0 >>> [ 1404.894646] [] ? kthread_create_on_node+0x180/0x180 >>> [ 1404.896553] [] ? ret_from_fork+0x58/0x90 >>> [ 1404.898556] [] ? kthread_create_on_node+0x180/0x180 >>> [ 1404.900597] Code: 09 00 00 48 89 ea 4c 89 f6 48 89 df e8 52 1b 00 >>> 00 85 c0 0f 88 82 02 00 00 0f b6 44 24 0f 4c 89 f7 88 45 09 49 8b 86 >>> d8 04 00 00 <4c> 8b a8 f8 01 00 00 49 8b 86 a0 04 00 00 ff 90 98 00 00 >>> 00 41 >>> [ 1404.906962] RIP [] >>> iscsi_target_login_thread+0x728/0x10b0 [iscsi_target_mod] >>> [ 1404.908962] RSP >>> [ 1404.910940] CR2: 00000000000001f8 >>> [ 1404.917670] ---[ end trace d29d8c681ab2bdfb ]--- >>> [ 1419.859690] iSCSI Login timeout on Network Portal 10.182.70.69:3260 >>> [ 1479.832056] iSCSI Login timeout on Network Portal 10.182.70.68:3260 >>> [ 1479.835739] iSCSI Login negotiation failed. >>> [ 1549.332632] iSCSI Login timeout on Network Portal 10.182.70.68:3260 >>> [ 1549.338432] iSCSI Login negotiation failed. >>> [ 1564.358423] iSCSI Login timeout on Network Portal 10.182.70.68:3260 >>> [ 1564.362443] iSCSI Login negotiation failed. >>> >>> 2016-07-12 6:15 GMT+08:00 Feng Li : >>>> From: Feng Li >>>> >>>> In MC/S scenario, the conn->sess has been set NULL in >>>> iscsi_login_non_zero_tsih_s1 when the second connection comes here, >>>> then kernel panic. >>>> >>>> The conn->sess will be assigned in iscsi_login_non_zero_tsih_s2. So >>>> we should check whether it's NULL before calling. >>>> >>>> Signed-off-by: Feng Li >>>> --- >>>> drivers/target/iscsi/iscsi_target_login.c | 5 +++-- >>>> 1 file changed, 3 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c >>>> index b5212f0..adf419f 100644 >>>> --- a/drivers/target/iscsi/iscsi_target_login.c >>>> +++ b/drivers/target/iscsi/iscsi_target_login.c >>>> @@ -1371,8 +1371,9 @@ static int __iscsi_target_login_thread(struct iscsi_np *np) >>>> } >>>> login->zero_tsih = zero_tsih; >>>> >>>> - conn->sess->se_sess->sup_prot_ops = >>>> - conn->conn_transport->iscsit_get_sup_prot_ops(conn); >>>> + if (conn->sess) >>>> + conn->sess->se_sess->sup_prot_ops = >>>> + conn->conn_transport->iscsit_get_sup_prot_ops(conn); >>>> >>>> tpg = conn->tpg; >>>> if (!tpg) { >>>> -- >>>> 2.9.0 >>>> >>> >>> >>> >>> -- >>> Thanks and Best Regards, >>> Feng Li(Alex) >> >> >> >> -- >> Thanks and Best Regards, >> Feng Li(Alex) > -- Thanks and Best Regards, Feng Li(Alex)