From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754272Ab3LMW22 (ORCPT ); Fri, 13 Dec 2013 17:28:28 -0500 Received: from mail-pd0-f173.google.com ([209.85.192.173]:45585 "EHLO mail-pd0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754103Ab3LMW2W (ORCPT ); Fri, 13 Dec 2013 17:28:22 -0500 From: John Stultz To: LKML Cc: Greg KH , Android Kernel Team , Sumit Semwal , Jesse Barker , Colin Cross , John Stultz Subject: [PATCH 086/115] ion: fix crash when alloc len is -1 Date: Fri, 13 Dec 2013 14:25:00 -0800 Message-Id: <1386973529-4884-87-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1386973529-4884-1-git-send-email-john.stultz@linaro.org> References: <1386973529-4884-1-git-send-email-john.stultz@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Cross If userspace passes a length between -4095 and -1 to allocate it will pass the len != 0 check, but when len is page aligned it will be 0. Check len after page aligning. Drop the warning as well, userspace shouldn't be able to trigger a warning in the kernel. Signed-off-by: Colin Cross Signed-off-by: John Stultz --- drivers/staging/android/ion/ion.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index cf9fc78..2e7be70 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -485,11 +485,11 @@ struct ion_handle *ion_alloc(struct ion_client *client, size_t len, * request of the caller allocate from it. Repeat until allocate has * succeeded or all heaps have been tried */ - if (WARN_ON(!len)) - return ERR_PTR(-EINVAL); - len = PAGE_ALIGN(len); + if (!len) + return ERR_PTR(-EINVAL); + down_read(&dev->lock); plist_for_each_entry(heap, &dev->heaps, node) { /* if the caller didn't specify this heap id */ -- 1.8.3.2