another added

2 files changed, 49 insertions, 0 deletions

diff --git a/block-blk_init_allocated_queue-set-q-fq-as-null-in-the-fail-case.patch b/block-blk_init_allocated_queue-set-q-fq-as-null-in-the-fail-case.patch
new file mode 100644
index 0000000..fa0a5cb
--- /dev/null
+++ b/block-blk_init_allocated_queue-set-q-fq-as-null-in-the-fail-case.patch
@@ -0,0 +1,48 @@
+From 54648cf1ec2d7f4b6a71767799c45676a138ca24 Mon Sep 17 00:00:00 2001
+From: xiao jin <jin.xiao@intel.com>
+Date: Mon, 30 Jul 2018 14:11:12 +0800
+Subject: block: blk_init_allocated_queue() set q->fq as NULL in the fail case
+
+From: xiao jin <jin.xiao@intel.com>
+
+commit 54648cf1ec2d7f4b6a71767799c45676a138ca24 upstream.
+
+We find the memory use-after-free issue in __blk_drain_queue()
+on the kernel 4.14. After read the latest kernel 4.18-rc6 we
+think it has the same problem.
+
+Memory is allocated for q->fq in the blk_init_allocated_queue().
+If the elevator init function called with error return, it will
+run into the fail case to free the q->fq.
+
+Then the __blk_drain_queue() uses the same memory after the free
+of the q->fq, it will lead to the unpredictable event.
+
+The patch is to set q->fq as NULL in the fail case of
+blk_init_allocated_queue().
+
+Fixes: commit 7c94e1c157a2 ("block: introduce blk_flush_queue to drive flush machinery")
+Cc: <stable@vger.kernel.org>
+Reviewed-by: Ming Lei <ming.lei@redhat.com>
+Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
+Signed-off-by: xiao jin <jin.xiao@intel.com>
+Signed-off-by: Jens Axboe <axboe@kernel.dk>
+[groeck: backport to v4.4.y/v4.9.y (context change)]
+Signed-off-by: Guenter Roeck <linux@roeck-us.net>
+Signed-off-by: Alessio Balsini <balsini@android.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ block/blk-core.c |    1 +
+ 1 file changed, 1 insertion(+)
+
+--- a/block/blk-core.c
++++ b/block/blk-core.c
+@@ -747,6 +747,7 @@ blk_init_allocated_queue(struct request_
+ 
+ fail:
+ 	blk_free_flush_queue(q->fq);
++	q->fq = NULL;
+ 	return NULL;
+ }
+ EXPORT_SYMBOL(blk_init_allocated_queue);
diff --git a/series b/series
index 9681bea..a5df0fb 100644
--- a/series
+++ b/series
@@ -2,3 +2,4 @@ net-fix-ifindex-collision-during-namespace-removal.patch
 net-sched-fix-a-possible-null-pointer-dereference-in-dequeue_func.patch
 net-bridge-delete-local-fdb-on-device-init-failure.patch
 bnx2x-disable-multi-cos-feature.patch
+block-blk_init_allocated_queue-set-q-fq-as-null-in-the-fail-case.patch