From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757775Ab3JKJzg (ORCPT ); Fri, 11 Oct 2013 05:55:36 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:41153 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757751Ab3JKJzc (ORCPT ); Fri, 11 Oct 2013 05:55:32 -0400 X-Sasl-enc: KHVbOp0cp5M/WDugIUASKYJF4c2YGDwyeIVspGOH6zQ8 1381485330 Message-ID: <1381485327.2631.18.camel@perseus.fritz.box> Subject: Re: NULL pointer dereference in autofs4_expire_wait From: Ian Kent To: David Ahern Cc: autofs@vger.kernel.org, viro@ZenIV.linux.org.uk, linux-kernel@vger.kernel.org Date: Fri, 11 Oct 2013 17:55:27 +0800 In-Reply-To: <1381457199.2631.3.camel@perseus.fritz.box> References: <525736C7.9080400@gmail.com> <1381457199.2631.3.camel@perseus.fritz.box> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4 (3.6.4-3.fc18) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2013-10-11 at 10:06 +0800, Ian Kent wrote: > On Thu, 2013-10-10 at 17:22 -0600, David Ahern wrote: > > Running 3.12-rc3 just hit BUG in autofs4_expire_wait > > It doesn't look like this could be due to Al's change to the locking in > autos4_wait() and that the only change to autofs that I'm aware of. > > Could you do a bisect please? Of course that assumes it's repeatable. Is it? Can you provide any information about the environment and activity that was happening at the time of the BUG()? > > > > > [787422.065405] BUG: unable to handle kernel NULL pointer dereference at > > 0000000000000010 > > [787422.065567] IP: [] autofs4_expire_wait+0x38/0x120 > > [787422.065659] PGD 163bdb067 PUD 163bbc067 PMD 0 > > [787422.065744] Oops: 0000 [#1] SMP > > [787422.065825] Modules linked in: binfmt_misc nfsv3 rpcsec_gss_krb5 > > nfsv4 dns_resolver nfs fscache bridge stp llc ipt_MASQUERADE xt_nat > > iptable_nat nf_nat_ipv4 nf_nat xt_physdev nf_conntrack_ipv4 > > nf_defrag_ipv4 xt_state nf_conntrack xt_multiport nfsd lockd nfs_acl > > auth_rpcgss sunrpc ipmi_si ipmi_msghandler vhost_net iTCO_wdt macvtap > > macvlan vhost iTCO_vendor_support pcspkr i7core_edac lpc_ich mfd_core > > tun edac_core bnx2 hpwdt microcode acpi_power_meter oid_registry > > kvm_intel kvm usb_storage hpsa ttm drm_kms_helper drm i2c_algo_bit i2c_core > > [787422.066557] CPU: 10 PID: 20498 Comm: sed Not tainted 3.12.0-rc3+ #8 > > [787422.066640] Hardware name: HP ProLiant DL380 G6, BIOS P62 05/05/2011 > > [787422.066722] task: ffff88030e941790 ti: ffff880182a16000 task.ti: > > ffff880182a16000 > > [787422.066872] RIP: 0010:[] [] > > autofs4_expire_wait+0x38/0x120 > > [787422.067029] RSP: 0000:ffff880182a17aa8 EFLAGS: 00010246 > > [787422.067121] RAX: 00000000b1acb1ac RBX: ffff8802e1056a80 RCX: > > 0000000000000010 > > [787422.067270] RDX: 000000000000b1ac RSI: ffffffff81c3e3e0 RDI: > > ffff88060e187d98 > > [787422.067457] RBP: ffff880182a17ad8 R08: 0000000000000000 R09: > > ffffffff811a5748 > > [787422.067607] R10: ff030306ff030001 R11: ffffffffffffffff R12: > > ffff88060e187d00 > > [787422.067758] R13: 0000000000000000 R14: 0000000000637461 R15: > > ffff8802e1056a80 > > [787422.067909] FS: 0000000000000000(0000) GS:ffff880313ca0000(0000) > > knlGS:0000000000000000 > > [787422.068061] CS: 0010 DS: 002b ES: 002b CR0: 000000008005003b > > [787422.068141] CR2: 0000000000000010 CR3: 000000010f106000 CR4: > > 00000000000027e0 > > [787422.068302] Stack: > > [787422.068414] ffff880182a17af8 ffffffff810768fe 0000000000000100 > > ffff8802e1056a80 > > [787422.068575] ffff88060e187dc0 ffff88060e187dc0 ffff880182a17b48 > > ffffffff8126f5fc > > [787422.068736] 0000000000000000 ffff880192afb890 ffff8802e1056ab8 > > 0000000392afb890 > > [787422.068896] Call Trace: > > [787422.068976] [] ? prepare_to_wait+0x5e/0x90 > > [787422.069060] [] do_expire_wait+0x17c/0x190 > > [787422.069142] [] autofs4_d_manage+0xb4/0x170 > > [787422.069227] [] follow_managed+0xcd/0x2c0 > > [787422.069323] [] lookup_slow+0x7b/0xaa > > [787422.069441] [] link_path_walk+0x34a/0x8d0 > > [787422.069524] [] ? dput+0x31/0x1f0 > > [787422.069606] [] ? mntput_no_expire+0x49/0x140 > > [787422.069690] [] ? path_init+0x30c/0x400 > > [787422.069772] [] path_lookupat+0x58/0x740 > > [787422.069856] [] ? kmem_cache_alloc+0x1c3/0x200 > > [787422.069939] [] ? kmem_cache_alloc+0x19d/0x200 > > [787422.071815] [] filename_lookup+0x34/0xc0 > > [787422.071898] [] user_path_at_empty+0x59/0xa0 > > [787422.071981] [] ? do_filp_open+0x43/0xa0 > > [787422.072064] [] user_path_at+0x11/0x20 > > [787422.072146] [] vfs_fstatat+0x51/0xb0 > > [787422.072228] [] vfs_stat+0x1b/0x20 > > [787422.072311] [] sys32_stat64+0x1a/0x40 > > [787422.072453] [] ? do_sys_open+0x1aa/0x220 > > [787422.072539] [] ia32_do_call+0x13/0x13 > > [787422.072619] Code: 48 89 5d e8 4c 89 65 f0 48 89 fb 4c 89 6d f8 48 8b > > 47 68 4c 8b 6f 78 4c 8b a0 00 03 00 00 49 8d bc 24 98 00 00 00 e8 78 0d > > 3c 00 <41> f6 45 10 01 74 61 66 41 83 84 24 98 00 00 00 01 f6 05 52 4a > > [787422.073004] RIP [] autofs4_expire_wait+0x38/0x120 > > [787422.073089] RSP > > [787422.073164] CR2: 0000000000000010 > > [787422.073595] ---[ end trace c75e278f6383bf9a ]--- >