From: Chris Wilson <chris@chris-wilson.co.uk>
To: Imre Deak <imre.deak@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH v2] drm/i915: fix pch pci device enumeration
Date: Fri, 14 Feb 2014 18:36:01 +0000 [thread overview]
Message-ID: <20140214183601.GM32602@nuc-i3427.alporthouse.com> (raw)
In-Reply-To: <1392402234-15479-1-git-send-email-imre.deak@intel.com>
On Fri, Feb 14, 2014 at 08:23:54PM +0200, Imre Deak wrote:
> pci_get_class(class, from) drops the refcount for 'from', so the
> extra pci_dev_put we do on it will result in a use after free bug
> starting with the WARN below.
>
> Regression introduced in
>
> commit 6a9c4b35e6696a63805b6da5e4889c6986e9ee1b
> Author: Rui Guo <firemeteor@users.sourceforge.net>
> Date: Wed Jun 19 21:10:23 2013 +0800
>
> drm/i915: Fix PCH detect with multiple ISA bridges in VM
>
> [ 164.338460] WARNING: CPU: 1 PID: 2094 at include/linux/kref.h:47 klist_next+0xae/0x110()
> [ 164.347731] CPU: 1 PID: 2094 Comm: modprobe Tainted: G O 3.13.0-imre+ #354
> [ 164.356468] Hardware name: Intel Corp. VALLEYVIEW B0 PLATFORM/NOTEBOOK, BIOS BYTICRB1.X64.0062.R70.1310112051 10/11/2013
> [ 164.368796] Call Trace:
> [ 164.371609] [<ffffffff816a32a6>] dump_stack+0x4e/0x7a
> [ 164.377447] [<ffffffff8104f75d>] warn_slowpath_common+0x7d/0xa0
> [ 164.384238] [<ffffffff8104f83a>] warn_slowpath_null+0x1a/0x20
> [ 164.390851] [<ffffffff8169aeae>] klist_next+0xae/0x110
> [ 164.396777] [<ffffffff8130a110>] ? pci_do_find_bus+0x70/0x70
> [ 164.403286] [<ffffffff813cb4a9>] bus_find_device+0x89/0xc0
> [ 164.409719] [<ffffffff8130a373>] pci_get_dev_by_id+0x63/0xa0
> [ 164.416238] [<ffffffff8130a4e4>] pci_get_class+0x44/0x50
> [ 164.422433] [<ffffffffa034821f>] intel_dsm_detect+0x16f/0x1f0 [i915]
> [ 164.429801] [<ffffffffa03482ae>] intel_register_dsm_handler+0xe/0x10 [i915]
> [ 164.437831] [<ffffffffa02d30fe>] i915_driver_load+0xafe/0xf30 [i915]
> [ 164.445126] [<ffffffff8158a150>] ? intel_alloc_coherent+0x110/0x110
> [ 164.452340] [<ffffffffa0148c07>] drm_dev_register+0xc7/0x150 [drm]
> [ 164.459462] [<ffffffffa014b23f>] drm_get_pci_dev+0x11f/0x1f0 [drm]
> [ 164.466554] [<ffffffff816abb81>] ? _raw_spin_unlock_irqrestore+0x51/0x70
> [ 164.474287] [<ffffffffa02cf7a6>] i915_pci_probe+0x56/0x60 [i915]
> [ 164.481185] [<ffffffff8130a028>] pci_device_probe+0x78/0xf0
> [ 164.487603] [<ffffffff813cd495>] driver_probe_device+0x155/0x350
> [ 164.494505] [<ffffffff813cd74e>] __driver_attach+0x6e/0xa0
> [ 164.500826] [<ffffffff813cd6e0>] ? __device_attach+0x50/0x50
> [ 164.507333] [<ffffffff813cb2be>] bus_for_each_dev+0x6e/0xc0
> [ 164.513752] [<ffffffff813ccefe>] driver_attach+0x1e/0x20
> [ 164.519870] [<ffffffff813cc958>] bus_add_driver+0x138/0x260
> [ 164.526289] [<ffffffffa0188000>] ? 0xffffffffa0187fff
> [ 164.532116] [<ffffffff813cde78>] driver_register+0x98/0xe0
> [ 164.538558] [<ffffffffa0188000>] ? 0xffffffffa0187fff
> [ 164.544389] [<ffffffff813087b0>] __pci_register_driver+0x60/0x70
> [ 164.551336] [<ffffffffa014b37d>] drm_pci_init+0x6d/0x120 [drm]
> [ 164.558040] [<ffffffffa0188000>] ? 0xffffffffa0187fff
> [ 164.563928] [<ffffffffa018806a>] i915_init+0x6a/0x6c [i915]
> [ 164.570363] [<ffffffff810002da>] do_one_initcall+0xaa/0x160
> [ 164.576783] [<ffffffff8103b140>] ? set_memory_nx+0x40/0x50
> [ 164.583100] [<ffffffff810ce7f5>] load_module+0x1fb5/0x2550
> [ 164.589410] [<ffffffff810caab0>] ? store_uevent+0x40/0x40
> [ 164.595628] [<ffffffff810cee7d>] SyS_init_module+0xed/0x100
> [ 164.602048] [<ffffffff816b3c52>] system_call_fastpath+0x16/0x1b
>
> v2: simplify the loop further (Chris)
>
> Signed-off-by: Imre Deak <imre.deak@intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Reported-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=65652
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=74161
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
--
Chris Wilson, Intel Open Source Technology Centre
next prev parent reply other threads:[~2014-02-14 18:36 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-14 17:23 [PATCH] drm/i915: fix pch pci device enumeration Imre Deak
2014-02-14 17:35 ` Chris Wilson
2014-02-14 17:48 ` Imre Deak
2014-02-14 17:54 ` Chris Wilson
2014-02-14 17:56 ` Imre Deak
2014-02-14 18:23 ` [PATCH v2] " Imre Deak
2014-02-14 18:36 ` Chris Wilson [this message]
2014-02-28 14:12 ` Jani Nikula
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