From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:53069 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750717AbcCETlu (ORCPT ); Sat, 5 Mar 2016 14:41:50 -0500 Subject: Patch "bio: return EINTR if copying to user space got interrupted" has been added to the 3.14-stable tree To: hare@suse.de, axboe@fb.com, gregkh@linuxfoundation.org, jthumshirn@suse.de Cc: , From: Date: Sat, 05 Mar 2016 11:41:49 -0800 Message-ID: <145720690992127@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled bio: return EINTR if copying to user space got interrupted to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bio-return-eintr-if-copying-to-user-space-got-interrupted.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 2d99b55d378c996b9692a0c93dd25f4ed5d58934 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 From: Hannes Reinecke 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 Cc: stable@vger.kernel.org # v.3.11+ Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/bio.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/fs/bio.c +++ b/fs/bio.c @@ -1096,9 +1096,12 @@ 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); Patches currently in stable-queue which might be from hare@suse.de are queue-3.14/bio-return-eintr-if-copying-to-user-space-got-interrupted.patch