From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762965AbZFMQJ6 (ORCPT ); Sat, 13 Jun 2009 12:09:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755055AbZFMQJv (ORCPT ); Sat, 13 Jun 2009 12:09:51 -0400 Received: from victor.provo.novell.com ([137.65.250.26]:44551 "EHLO victor.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753046AbZFMQJu (ORCPT ); Sat, 13 Jun 2009 12:09:50 -0400 Subject: BUG in pty_chars_in_buffer with 2.6.30 git head using ssh From: James Bottomley To: linux-kernel Content-Type: text/plain Date: Sat, 13 Jun 2009 11:09:34 -0500 Message-Id: <1244909374.5323.23.camel@mulgrave.site> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a really odd one. I've used ssh into this box with this same kernel several times before, I got this (actually logged out as me over ssh then logged back in as root): ssh used greatest stack depth: 5340 bytes left BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] pty_chars_in_buffer+0x13/0x50 *pde = 00000000 Oops: 0000 [#1] SMP last sysfs file: /sys/devices/pci0000:00/0000:00:1c.4/0000:04:00.0/irq Modules linked in: nfsd exportfs nfs lockd auth_rpcgss sunrpc dm_snapshot dm_mirror dm_region_hash dm_log serio_raw i3000_edac rtc_cmos rtc_core rtc_lib ext3 jbd mbcache sg sr_mod cdrom sd_mod uhci_hcd aic94xx libsas libata usbcore tg3 libphy aic7xxx scsi_transport_spi scsi_transport_sas scsi_mod Pid: 17335, comm: sshd Tainted: G W (2.6.30 #66) IBM eServer 206m-[8485IZZ]- EIP: 0060:[] EFLAGS: 00010282 CPU: 0 EIP is at pty_chars_in_buffer+0x13/0x50 EAX: 00000000 EBX: f6da08c8 ECX: f6da08c8 EDX: f61085b0 ESI: 00000000 EDI: f62e4200 EBP: f7a25b0c ESP: f7a25b08 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 Process sshd (pid: 17335, ti=f7a24000 task=f5e6e0b0 task.ti=f7a24000) Stack: f6da08c8 f7a25b14 c11890e5 f7a25b2c c1186e77 00a25b2c 00000000 f62e4200 f6da08c8 f7a25b4c c118318a 00000000 c1186d60 f60897c0 0000000b 00000800 f62e4200 f7a25e34 c10b810f 000000b2 f7a25bb0 00000000 f7a25bd4 00000020 Call Trace: [] ? tty_chars_in_buffer+0x15/0x20 [] ? n_tty_poll+0x117/0x140 [] ? tty_poll+0x5a/0x70 [] ? n_tty_poll+0x0/0x140 [] ? do_select+0x32f/0x690 [] ? __pollwait+0x0/0xc0 [] ? pollwake+0x0/0x50 [] ? pollwake+0x0/0x50 [] ? pollwake+0x0/0x50 [] ? pollwake+0x0/0x50 [] ? pollwake+0x0/0x50 [] ? pollwake+0x0/0x50 [] ? lock_timer_base+0x1f/0x40 [] ? _spin_lock_irqsave+0x2c/0x40 [] ? mod_timer+0x9d/0xd0 [] ? trace_hardirqs_on+0xb/0x10 [] ? mod_timer+0x9d/0xd0 [] ? tcp_event_new_data_sent+0x85/0xc0 [] ? tcp_write_xmit+0x1e8/0xa40 [] ? release_sock+0x26/0xc0 [] ? trace_hardirqs_on+0xb/0x10 [] ? local_bh_enable_ip+0x72/0xc0 [] ? might_fault+0x3f/0x80 [] ? might_fault+0x3f/0x80 [] ? might_fault+0x7a/0x80 [] ? core_sys_select+0x1e2/0x330 [] ? do_sync_write+0xcc/0x110 [] ? autoremove_wake_function+0x0/0x40 [] ? sys_select+0x27/0xc0 [] ? sys_write+0x3b/0x70 [] ? trace_hardirqs_on_thunk+0xc/0x10 [] ? syscall_call+0x7/0xb Code: 1c 01 00 00 5d c3 66 90 31 c0 5d c3 8d b6 00 00 00 00 8d bf 00 00 00 00 55 89 e5 53 8b 90 20 01 00 00 89 c3 85 d2 74 30 8b 42 54 <8b> 00 8b 48 1c 85 c9 74 24 89 d0 ff d1 89 c2 8b 43 08 66 83 78 EIP: [] pty_chars_in_buffer+0x13/0x50 SS:ESP 0068:f7a25b08 CR2: 0000000000000000 ---[ end trace 4eaa2a86a8e2da25 ]--- And the machine wedged hard. ssh had got part way to establishing a connection from the other machine according to netstat -a. On reboot, I was able to log in as root perfectly fine. James