From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p21114TD167057 for ; Mon, 28 Feb 2011 19:01:04 -0600 Received: from mail.mnsu.edu (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 3E8EA30577B for ; Mon, 28 Feb 2011 17:03:52 -0800 (PST) Received: from mail.mnsu.edu (Mail.MNSU.EDU [134.29.1.12]) by cuda.sgi.com with ESMTP id DtiCzlpFvAze7le6 for ; Mon, 28 Feb 2011 17:03:52 -0800 (PST) Message-ID: <4D6C45EE.80203@mnsu.edu> Date: Mon, 28 Feb 2011 19:03:42 -0600 From: Jeffrey Hundstad MIME-Version: 1.0 Subject: Re: kernel panic - stack-protector: kernel stack is corrupted in: f87aca93 References: <4D6C28A5.60905@mnsu.edu> <4D6C372E.6030105@sandeen.net> In-Reply-To: <4D6C372E.6030105@sandeen.net> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Eric Sandeen Cc: xfs@oss.sgi.com On 02/28/2011 06:00 PM, Eric Sandeen wrote: > On 2/28/11 4:58 PM, Jeffrey Hundstad wrote: > >> Hello, >> >> I'm compiling the main Linux branch commit 493f3358cb289ccf716c5a14fa5bb52ab75943e5 with no other patches. It boots and seems to operate fine. When I do an xfs_fsr it Kernel panics. I can easily reproduce it >> >> Kernel Panic: (hand copied, photo available) >> >> Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: f87aca93 >> >> Pid: 262, comm: xfs_fsr Not tainted 2.6.38-rc6-493f3358cb2+ #1 >> Call Trace: >> >> [] ? panic+0x50/0x150 >> [] ? __stack_chk_fail+0x10/0x18 >> [] ? xfs_ioc_fsgeometry_v1+0x56/0x5d [xfs] >> [] ? xfs_ioc_fsgeometry_v1+0x56/0x5d [xfs] >> [] ? xfs_file_ioctl+0x33c/0x6fe [xfs] >> [] ? sched_clock_cpu+0x130/0x140 >> [] ? trace_hardirqs_off+0xb/0xd >> [] ? local_clock+0x2d/0x4e >> [] ? lock_release_holdtime+0x2b/0xcd >> [] ? check_valid_pointer+0x1c/0x48 >> [] ? check_object+0x122/0x156 >> [] ? xfs_file_ioctl+0x0/0x6fe [xfs] >> [] ? do_vfs_ioctl+0x483/0x4c8 >> [] ? kmeme_chache_free+0x8f/0x9b >> [] ? fcheck_files+0xa1/0xd0 >> [] ? sys_ioctl+0x41/0x61 >> [] ? sysenter_do_call+0x12/0x32 >> >> >> >> You can find the config, initrd.img, vmlinuz and crash screen at: >> http://krypton.mnsu.edu/~j3gum/linux-error-20110228/ >> >> - gcc (Debian 4.4.5-13) 4.4.5 >> - xfs_fsr version 3.1.4 >> >> >> Please let know if you'd like more info. >> >> > I tried to extract your vmlinuz to a vmlinux to disassemble and look at stack usage of functions, but that was painful and did not seem to work out in the end. :) > > Can you do: > > objdump -d vmlinux | scripts/checkstack.pl > > and similar for xfs if it's a module: > > objdump -d xfs.ko | scripts/checkstack.pl > > and see how big each of the functions on the above backtrace is, in your kernel? > > Sadly, I didn't have the vmlinux file around anymore. I'll be glad to recreate it when I get in tomorrow. However, I have revered commit 3a3675b7f23f83ca8c67c9c2b6edf707fd28d1ba and the problem seems to have vanished. I'm guessing the stack at this point is a little to fragile for a memset. The patch is: commit 3a3675b7f23f83ca8c67c9c2b6edf707fd28d1ba Author: Dan Rosenberg Date: Mon Feb 14 13:45:28 2011 +0000 xfs: prevent leaking uninitialized stack memory in FSGEOMETRY_V1 The FSGEOMETRY_V1 ioctl (and its compat equivalent) calls out to xfs_fs_geometry() with a version number of 3. This code path does not fill in the logsunit member of the passed xfs_fsop_geom_t, leading to the leaking of four bytes of uninitialized stack data to potentially unprivileged callers. v2 switches to memset() to avoid future issues if structure members change, on suggestion of Dave Chinner. Signed-off-by: Dan Rosenberg Reviewed-by: Eugene Teo Signed-off-by: Alex Elder diff --git b/fs/xfs/xfs_fsops.c a/fs/xfs/xfs_fsops.c index cec89dd..85668ef 100644 --- b/fs/xfs/xfs_fsops.c +++ a/fs/xfs/xfs_fsops.c @@ -53,6 +53,9 @@ xfs_fs_geometry( xfs_fsop_geom_t *geo, int new_version) { + + memset(geo, 0, sizeof(*geo)); + geo->blocksize = mp->m_sb.sb_blocksize; geo->rtextsize = mp->m_sb.sb_rextsize; geo->agblocks = mp->m_sb.sb_agblocks; _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs