From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755907Ab0C3XJL (ORCPT ); Tue, 30 Mar 2010 19:09:11 -0400 Received: from kroah.org ([198.145.64.141]:48515 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755842Ab0C3XJI (ORCPT ); Tue, 30 Mar 2010 19:09:08 -0400 X-Mailbox-Line: From linux@linux.site Tue Mar 30 15:49:56 2010 Message-Id: <20100330224956.153081018@linux.site> User-Agent: quilt/0.47-14.9 Date: Tue, 30 Mar 2010 15:48:44 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Alan Stern , Marcus Meissner , Greg Kroah-Hartman Subject: [24/45] USB: usbfs: properly clean up the as structure on error paths In-Reply-To: <20100330230410.GA28712@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Linus Torvalds commit ddeee0b2eec2a51b0712b04de4b39e7bec892a53 upstream. I notice that the processcompl_compat() function seems to be leaking the 'struct async *as' in the error paths. I think that the calling convention is fundamentally buggered. The caller is the one that did the "reap_as()" to get the as thing, the caller should be the one to free it too. Freeing it in the caller also means that it very clearly always gets freed, and avoids the need for any "free in the error case too". From: Linus Torvalds Cc: Alan Stern Cc: Marcus Meissner Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/devio.c | 40 ++++++++++++++++++++++++++-------------- 1 file changed, 26 insertions(+), 14 deletions(-) --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -1246,14 +1246,11 @@ static int processcompl(struct async *as } } - free_async(as); - if (put_user(addr, (void __user * __user *)arg)) return -EFAULT; return 0; err_out: - free_async(as); return -EFAULT; } @@ -1283,8 +1280,11 @@ static struct async *reap_as(struct dev_ static int proc_reapurb(struct dev_state *ps, void __user *arg) { struct async *as = reap_as(ps); - if (as) - return processcompl(as, (void __user * __user *)arg); + if (as) { + int retval = processcompl(as, (void __user * __user *)arg); + free_async(as); + return retval; + } if (signal_pending(current)) return -EINTR; return -EIO; @@ -1292,11 +1292,16 @@ static int proc_reapurb(struct dev_state static int proc_reapurbnonblock(struct dev_state *ps, void __user *arg) { + int retval; struct async *as; - if (!(as = async_getcompleted(ps))) - return -EAGAIN; - return processcompl(as, (void __user * __user *)arg); + as = async_getcompleted(ps); + retval = -EAGAIN; + if (as) { + retval = processcompl(as, (void __user * __user *)arg); + free_async(as); + } + return retval; } #ifdef CONFIG_COMPAT @@ -1369,7 +1374,6 @@ static int processcompl_compat(struct as } } - free_async(as); if (put_user(ptr_to_compat(addr), (u32 __user *)arg)) return -EFAULT; return 0; @@ -1378,8 +1382,11 @@ static int processcompl_compat(struct as static int proc_reapurb_compat(struct dev_state *ps, void __user *arg) { struct async *as = reap_as(ps); - if (as) - return processcompl_compat(as, (void __user * __user *)arg); + if (as) { + int retval = processcompl_compat(as, (void __user * __user *)arg); + free_async(as); + return retval; + } if (signal_pending(current)) return -EINTR; return -EIO; @@ -1387,11 +1394,16 @@ static int proc_reapurb_compat(struct de static int proc_reapurbnonblock_compat(struct dev_state *ps, void __user *arg) { + int retval; struct async *as; - if (!(as = async_getcompleted(ps))) - return -EAGAIN; - return processcompl_compat(as, (void __user * __user *)arg); + retval = -EAGAIN; + as = async_getcompleted(ps); + if (as) { + retval = processcompl_compat(as, (void __user * __user *)arg); + free_async(as); + } + return retval; } #endif