From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: 2.6.17-mm4 Date: Thu, 29 Jun 2006 23:09:50 +0200 Message-ID: <20060629210950.GA300@elte.hu> References: <20060629013643.4b47e8bd.akpm@osdl.org> <6bffcb0e0606291339s69a16bc5ie108c0b8d4e29ed6@mail.gmail.com> <20060629204330.GC13619@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx3.mail.elte.hu ([157.181.1.138]:17621 "EHLO mx3.mail.elte.hu") by vger.kernel.org with ESMTP id S932464AbWF2VOe (ORCPT ); Thu, 29 Jun 2006 17:14:34 -0400 To: Dave Jones , Michal Piotrowski , Andrew Morton , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Content-Disposition: inline In-Reply-To: <20060629204330.GC13619@redhat.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org * Dave Jones wrote: > On Thu, Jun 29, 2006 at 10:39:33PM +0200, Michal Piotrowski wrote: > > > This looks very strange. > > > > BUG: unable to handle kernel paging request at virtual address 6b6b6c07 > > Looks like a use after free. i'm too hunting use-after-free bugs - the ones fixed below fix certain crashes, but i'm still seeing a nasty one. the crash is independent on lockdep enabled or disabled. See: http://redhat.com/~mingo/misc/ for the config and the crash.log. Ingo ----------------- Subject: fix platform_device_put/del mishaps From: Ingo Molnar this fixes drivers/char/pc8736x_gpio.c and drivers/char/scx200_gpio.c to use the platform_device_del/put ops correctly. Signed-off-by: Ingo Molnar --- drivers/char/pc8736x_gpio.c | 5 +++-- drivers/char/scx200_gpio.c | 6 +++--- 2 files changed, 6 insertions(+), 5 deletions(-) Index: linux/drivers/char/pc8736x_gpio.c =================================================================== --- linux.orig/drivers/char/pc8736x_gpio.c +++ linux/drivers/char/pc8736x_gpio.c @@ -319,9 +319,10 @@ static int __init pc8736x_gpio_init(void return 0; undo_platform_dev_add: - platform_device_put(pdev); + platform_device_del(pdev); undo_platform_dev_alloc: - kfree(pdev); + platform_device_put(pdev); + return rc; } Index: linux/drivers/char/scx200_gpio.c =================================================================== --- linux.orig/drivers/char/scx200_gpio.c +++ linux/drivers/char/scx200_gpio.c @@ -126,9 +126,10 @@ static int __init scx200_gpio_init(void) undo_chrdev_region: unregister_chrdev_region(dev, num_pins); undo_platform_device_add: - platform_device_put(pdev); + platform_device_del(pdev); undo_malloc: - kfree(pdev); + platform_device_put(pdev); + return rc; } @@ -136,7 +137,6 @@ static void __exit scx200_gpio_cleanup(v { kfree(scx200_devices); unregister_chrdev_region(MKDEV(major, 0), num_pins); - platform_device_put(pdev); platform_device_unregister(pdev); /* kfree(pdev); */ }