From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail333.us4.mandrillapp.com ([205.201.137.77]:53200 "EHLO mail333.us4.mandrillapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752567AbcCAWXS (ORCPT ); Tue, 1 Mar 2016 17:23:18 -0500 Received: from pmta03.dal05.mailchimp.com (127.0.0.1) by mail333.us4.mandrillapp.com id hqob5c174nos for ; Tue, 1 Mar 2016 22:23:17 +0000 (envelope-from ) From: Subject: Patch "bio: return EINTR if copying to user space got interrupted" has been added to the 4.4-stable tree To: , , , Cc: , Message-Id: <1456870994226206@kroah.com> Date: Tue, 01 Mar 2016 22:23:16 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit 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 4.4-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-4.4 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 Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- block/bio.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/block/bio.c +++ b/block/bio.c @@ -1090,9 +1090,12 @@ int bio_uncopy_user(struct bio *bio) if (!bio_flagged(bio, BIO_NULL_MAPPED)) { /* * if we're in a workqueue, the request is orphaned, so - * don't copy into a random user address space, just free. + * don't copy into a random user address space, just free + * and return -EINTR so user space doesn't expect any data. */ - if (current->mm && bio_data_dir(bio) == READ) + if (!current->mm) + ret = -EINTR; + else if (bio_data_dir(bio) == READ) ret = bio_copy_to_iter(bio, bmd->iter); if (bmd->is_our_pages) bio_free_pages(bio); Patches currently in stable-queue which might be from hare@suse.de are queue-4.4/target-fix-remote-port-tmr-abort-se_cmd-fabric-stop.patch queue-4.4/target-fix-lun_reset-active-tmr-descriptor-handling.patch queue-4.4/target-fix-race-with-scf_send_delayed_tas-handling.patch queue-4.4/bio-return-eintr-if-copying-to-user-space-got-interrupted.patch queue-4.4/target-fix-lun_reset-active-i-o-handling-for-ack_kref.patch queue-4.4/target-fix-tas-handling-for-multi-session-se_node_acls.patch