linux-kernel - [PATCH] blk-mq: Fix a use-after-free

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <54523AA4.9010307@acm.org>
Date:	Thu, 30 Oct 2014 14:18:28 +0100
From:	Bart Van Assche <bvanassche@....org>
To:	Jens Axboe <axboe@...nel.dk>
CC:	Christoph Hellwig <hch@....de>, Robert Elliott <Elliott@...com>,
	Ming Lei <ming.lei@...onical.com>,
	linux-kernel <linux-kernel@...r.kernel.org>
Subject: [PATCH] blk-mq: Fix a use-after-free

Since the tag set structure can be embedded in a structure that
is freed before the last queue put occurs (e.g. the SCSI host
structure), the block layer must not access the tag set after the
SCSI host structure has been freed. This patch avoids that the
following kernel oops is triggered with memory poisoning enabled:

general protection fault: 0000 [#1] SMP
RAX: 0000000000000000 RBX: 6b6b6b6b6b6b6b6b RCX: 0000000000000000
Call Trace:
 [<ffffffff8109a7c4>] lock_acquire+0xc4/0x270
 [<ffffffff814ce111>] mutex_lock_nested+0x61/0x380
 [<ffffffff812575f0>] blk_mq_free_queue+0x30/0x180
 [<ffffffff8124d654>] blk_release_queue+0x84/0xd0
 [<ffffffff8126c29b>] kobject_cleanup+0x7b/0x1a0
 [<ffffffff8126c140>] kobject_put+0x30/0x70
 [<ffffffff81245895>] blk_put_queue+0x15/0x20
 [<ffffffff8125c409>] disk_release+0x99/0xd0
 [<ffffffff8133d056>] device_release+0x36/0xb0
 [<ffffffff8126c29b>] kobject_cleanup+0x7b/0x1a0
 [<ffffffff8126c140>] kobject_put+0x30/0x70
 [<ffffffff8125a78a>] put_disk+0x1a/0x20
 [<ffffffff811d4cb5>] __blkdev_put+0x135/0x1b0
 [<ffffffff811d56a0>] blkdev_put+0x50/0x160
 [<ffffffff81199eb4>] kill_block_super+0x44/0x70
 [<ffffffff8119a2a4>] deactivate_locked_super+0x44/0x60
 [<ffffffff8119a87e>] deactivate_super+0x4e/0x70
 [<ffffffff811b9833>] cleanup_mnt+0x43/0x90
 [<ffffffff811b98d2>] __cleanup_mnt+0x12/0x20
 [<ffffffff8107252c>] task_work_run+0xac/0xe0
 [<ffffffff81002c01>] do_notify_resume+0x61/0xa0
 [<ffffffff814d2c58>] int_signal+0x12/0x17

Signed-off-by: Bart Van Assche <bvanassche@....org>
Cc: Christoph Hellwig <hch@....de>
Cc: Robert Elliott  <Elliott@...com>
Cc: Ming Lei <ming.lei@...onical.com>
Cc: <stable@...r.kernel.org> # v3.12+
---
 block/blk-core.c  | 3 +++
 block/blk-sysfs.c | 4 +---
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 0421b53..93f9152 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -525,6 +525,9 @@ void blk_cleanup_queue(struct request_queue *q)
 	del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer);
 	blk_sync_queue(q);
 
+	if (q->mq_ops)
+		blk_mq_free_queue(q);
+
 	spin_lock_irq(lock);
 	if (q->queue_lock != &q->__queue_lock)
 		q->queue_lock = &q->__queue_lock;
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 1fac434..3ce0da1 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -517,9 +517,7 @@ static void blk_release_queue(struct kobject *kobj)
 	if (q->queue_tags)
 		__blk_queue_free_tags(q);
 
-	if (q->mq_ops)
-		blk_mq_free_queue(q);
-	else
+	if (!q->mq_ops)
 		blk_free_flush_queue(q->fq);
 
 	blk_trace_shutdown(q);
-- 
1.8.4.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/