From patchwork Tue Mar 8 12:24:42 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 594084 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 0599B1400CB; Tue, 8 Mar 2016 23:26:20 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1adGiP-0007EK-3d; Tue, 08 Mar 2016 12:26:17 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1adGgu-0006S2-4w for kernel-team@lists.ubuntu.com; Tue, 08 Mar 2016 12:24:44 +0000 Received: from av-217-129-142-138.netvisao.pt ([217.129.142.138] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1adGgt-0005OP-30; Tue, 08 Mar 2016 12:24:43 +0000 From: Luis Henriques To: Hannes Reinecke Subject: [3.16.y-ckt stable] Patch "bio: return EINTR if copying to user space got interrupted" has been added to the 3.16.y-ckt tree Date: Tue, 8 Mar 2016 12:24:42 +0000 Message-Id: <1457439882-19051-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Cc: Jens Axboe , kernel-team@lists.ubuntu.com, Johannes Thumshirn X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled bio: return EINTR if copying to user space got interrupted to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt26. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ---8<------------------------------------------------------------ From 04e0f4eebfe7419444dd5dd7ea476a7b25030054 Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Fri, 12 Feb 2016 09:39:15 +0100 Subject: bio: return EINTR if copying to user space got interrupted commit 2d99b55d378c996b9692a0c93dd25f4ed5d58934 upstream. Commit 35dc248383bbab0a7203fca4d722875bc81ef091 introduced a check for current->mm to see if we have a user space context and only copies data if we do. Now if an IO gets interrupted by a signal data isn't copied into user space any more (as we don't have a user space context) but user space isn't notified about it. This patch modifies the behaviour to return -EINTR from bio_uncopy_user() to notify userland that a signal has interrupted the syscall, otherwise it could lead to a situation where the caller may get a buffer with no data returned. This can be reproduced by issuing SG_IO ioctl()s in one thread while constantly sending signals to it. Fixes: 35dc248 [SCSI] sg: Fix user memory corruption when SG_IO is interrupted by a signal Signed-off-by: Johannes Thumshirn Signed-off-by: Hannes Reinecke Signed-off-by: Jens Axboe [ luis: backported to 3.16: based on Johannes' backport to 3.14 ] Signed-off-by: Luis Henriques --- block/bio.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/block/bio.c b/block/bio.c index 6467e6afdcd9..529e4195724e 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1110,9 +1110,12 @@ int bio_uncopy_user(struct bio *bio) ret = __bio_copy_iov(bio, bmd->sgvecs, bmd->nr_sgvecs, bio_data_dir(bio) == READ, 0, bmd->is_our_pages); - else if (bmd->is_our_pages) - bio_for_each_segment_all(bvec, bio, i) - __free_page(bvec->bv_page); + else { + ret = -EINTR; + if (bmd->is_our_pages) + bio_for_each_segment_all(bvec, bio, i) + __free_page(bvec->bv_page); + } } kfree(bmd); bio_put(bio);