From patchwork Fri Dec 7 16:05:26 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [3.5.y.z, extended, stable] Patch "s390/gup: add missing TASK_SIZE check to" has been added to staging queue Date: Fri, 07 Dec 2012 06:05:26 -0000 From: Herton Ronaldo Krzesinski X-Patchwork-Id: 204552 Message-Id: <1354896326-22522-1-git-send-email-herton.krzesinski@canonical.com> To: Heiko Carstens Cc: Martin Schwidefsky , kernel-team@lists.ubuntu.com, Gerald Schaefer This is a note to let you know that I have just added a patch titled s390/gup: add missing TASK_SIZE check to to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ >From 650c1926b6444071f3a2b42805415f8c59d11d12 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 22 Oct 2012 15:49:02 +0200 Subject: [PATCH] s390/gup: add missing TASK_SIZE check to get_user_pages_fast() commit d55c4c613fc4d4ad2ba0fc6fa2b57176d420f7e4 upstream. When walking page tables we need to make sure that everything is within bounds of the ASCE limit of the task's address space. Otherwise we might calculate e.g. a pud pointer which is not within a pud and dereference it. So check against TASK_SIZE (which is the ASCE limit) before walking page tables. Reviewed-by: Gerald Schaefer Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky Signed-off-by: Herton Ronaldo Krzesinski --- arch/s390/mm/gup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 1.7.9.5 diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c index 65cb06e..4ccf9f5 100644 --- a/arch/s390/mm/gup.c +++ b/arch/s390/mm/gup.c @@ -183,7 +183,7 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write, addr = start; len = (unsigned long) nr_pages << PAGE_SHIFT; end = start + len; - if (end < start) + if ((end < start) || (end > TASK_SIZE)) goto slow_irqon; /*