From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suman Anna Subject: Re: Nokia N900: refcount_t underflow, use after free Date: Mon, 12 Mar 2018 11:10:58 -0500 Message-ID: <5aa1e2de-96d1-0e88-01ca-49df9ae25457@ti.com> References: <20180308143053.GA17267@amd> <20180308165903.GM5799@atomide.com> <57c9f17b-fc9d-8506-4b5d-70ac216c9248@ti.com> <20180308185046.GA22796@amd> <1dfc05fe-1612-f5a5-b5f1-9038b3cecfe5@arm.com> <1643b74a-62ba-bea6-71c2-a2dd02430463@ti.com> <20180309221834.GA15476@amd> <20180310112634.GA31614@amd> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180310112634.GA31614@amd> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Pavel Machek Cc: ivo.g.dimitrov.75@gmail.com, aaro.koskinen@iki.fi, Tony Lindgren , khilman@kernel.org, kernel list , sre@kernel.org, martijn@brixit.nl, =?UTF-8?Q?Filip_Matijevi=c4=87?= , abcloriens@gmail.com, Laurent Pinchart , sakari.ailus@linux.intel.com, pali.rohar@gmail.com, clayton@craftyguy.net, linux-omap@vger.kernel.org, Robin Murphy , patrikbachan@gmail.com, linux-arm-kernel , serge@hallyn.com List-Id: linux-omap@vger.kernel.org On 03/10/2018 05:26 AM, Pavel Machek wrote: > Hi! > >>>>> Well, there certainly seems to be an obvious bug wherein >>>>> isp_detach_iommu() just releases the mapping directly without calling >>>>> arm_iommu_detach_device() to balance the equivalent attach. That can't >>>>> be helping. >>>> >>>> Indeed, I have been able to reproduce the same warning using a >>>> standalone test module, and the missing arm_iommu_detach_device() is >>>> causing the warning after probe (during failure path) or during >>>> remove. >>> >>> Ok do you have an idea how to fix the isp error paths? Untested patch >>> would be fine... But it seems that you know what needs to be fixed and >>> I don't. >>> >> >> OK, see if the following fixes the issue for you, only build tested. > > Word-wrapped, so I applied by hand. And yes, the oops at boot is > gone. Thanks! Sorry about that, have to check my mail settings. Anyway will post the patch again, glad that it fixed your issue. regards Suman > > (Camera still does not work in -next... kills system. Oh well. Lets > debug that some other day.) > >> 8< --------------------- >> >From bac9a48fb646dc51f2030d676a0dbe3298c3b134 Mon Sep 17 00:00:00 2001 >> From: Suman Anna >> Date: Fri, 9 Mar 2018 16:39:59 -0600 >> Subject: [PATCH] media: omap3isp: fix unbalanced dma_iommu_mapping >> >> The OMAP3 ISP driver manages its MMU mappings through the IOMMU-aware >> ARM DMA backend. The current code creates a dma_iommu_mapping and >> attaches this to the ISP device, but never detaches the mapping in >> either the probe failure paths or the driver remove path resulting >> in an unbalanced mapping refcount and a memory leak. Fix this properly. >> >> Reported-by: Pavel Machek >> Signed-off-by: Suman Anna > > Tested-by: Pavel Machek > Pavel >