From: Li Zefan <lizefan@huawei.com>
To: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Tejun Heo <tj@kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: next-20130306 - BUG: unable to handle kernel paging reques in avc_has_perm_noaudit
Date: Fri, 8 Mar 2013 11:15:47 +0800 [thread overview]
Message-ID: <513957E3.8000406@huawei.com> (raw)
In-Reply-To: <3077.1362687651@turing-police.cc.vt.edu>
On 2013/3/8 4:20, Valdis Kletnieks wrote:
> Seeing this in next-20130306:
>
> [ 180.958482] BUG: unable to handle kernel paging request at ffffffffffffffe0
> [ 180.958488] IP: [<ffffffff811e5661>] avc_has_perm_noaudit+0xbf/0x1bc
>
> [ 180.958506] Pid: 1910, comm: systemd-udevd Tainted: G O 3.9.0-rc1-next-20130306-dirty #64 Dell Inc. Latitude E6500
>
> [ 180.958537] [<ffffffff811e5790>] avc_has_perm_flags+0x32/0xe4
> [ 180.958540] [<ffffffff81071c81>] ? mark_lock+0x2e/0x225
> [ 180.958543] [<ffffffff811e5ada>] avc_has_perm+0xf/0x11
> [ 180.958546] [<ffffffff811e5e92>] selinux_inode_rename+0x84/0x138
> [ 180.958549] [<ffffffff811002b6>] ? __kmalloc_track_caller+0x107/0x119
> [ 180.958552] [<ffffffff811e36db>] security_inode_rename+0x6f/0x7a
> [ 180.958556] [<ffffffff81115a8f>] vfs_rename+0x1e2/0x36a
> [ 180.958558] [<ffffffff81115e04>] SYSC_renameat+0x1ed/0x282
> [ 180.958562] [<ffffffff81123485>] ? mntput+0x49/0x50
> [ 180.958566] [<ffffffff81068576>] ? __read_seqcount_retry.constprop.21+0x20/0x25
> [ 180.958568] [<ffffffff81068b1c>] ? current_kernel_time+0x2a/0x41
> [ 180.958572] [<ffffffff81094215>] ? __audit_syscall_entry+0xf9/0x125
> [ 180.958575] [<ffffffff8111681f>] SyS_renameat+0x9/0xb
> [ 180.958577] [<ffffffff81116837>] SyS_rename+0x16/0x1b
> [ 180.958581] [<ffffffff815f55d2>] system_call_fastpath+0x16/0x1b
>
> Most suspicious-looking recent commit in git log:
>
I don't think so. The commit changes cgroup_rename(), but the above stack doesn't
sugguest it was renaming a cgroup directory.
> ommit 65dff759d2948cf18e2029fc5c0c595b8b7da3a5
> Author: Li Zefan <lizefan@huawei.com>
> Date: Fri Mar 1 15:01:56 2013 +0800
>
> cgroup: fix cgroup_path() vs rename() race
>
> rename() will change dentry->d_name. The result of this race can
> be worse than seeing partially rewritten name, but we might access
> a stale pointer because rename() will re-allocate memory to hold
> a longer name.
>
> I admit not having any clue what crazy antics systemd was trying to do
> at the time. If this doesn't ring a bell, I'll go bisect it.
>
next prev parent reply other threads:[~2013-03-08 3:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-07 20:20 next-20130306 - BUG: unable to handle kernel paging reques in avc_has_perm_noaudit Valdis Kletnieks
2013-03-08 3:15 ` Li Zefan [this message]
2013-03-08 13:43 ` Valdis.Kletnieks
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