* [PATCH] block: blk_init_allocated_queue() set q->fq as NULL in the fail case
@ 2018-07-30 6:11 xiao jin
2018-07-30 12:06 ` Ming Lei
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: xiao jin @ 2018-07-30 6:11 UTC (permalink / raw)
To: axboe, linux-block, linux-kernel
Cc: tom.leiming, bart.vanassche, stable, yanmin.zhang, jin.xiao, Ming Lei
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")
Signed-off-by: xiao jin <jin.xiao@intel.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: <stable@vger.kernel.org>
---
block/blk-core.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/block/blk-core.c b/block/blk-core.c
index b888175..52635e2 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1072,6 +1072,7 @@ int blk_init_allocated_queue(struct request_queue *q)
q->exit_rq_fn(q, q->fq->flush_rq);
out_free_flush_queue:
blk_free_flush_queue(q->fq);
+ q->fq = NULL;
return -ENOMEM;
}
EXPORT_SYMBOL(blk_init_allocated_queue);
--
1.7.9.5
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] block: blk_init_allocated_queue() set q->fq as NULL in the fail case
2018-07-30 6:11 [PATCH] block: blk_init_allocated_queue() set q->fq as NULL in the fail case xiao jin
@ 2018-07-30 12:06 ` Ming Lei
2018-07-30 13:42 ` Bart Van Assche
2018-07-30 14:28 ` Jens Axboe
2 siblings, 0 replies; 5+ messages in thread
From: Ming Lei @ 2018-07-30 12:06 UTC (permalink / raw)
To: xiao jin
Cc: Jens Axboe, linux-block, Linux Kernel Mailing List,
Bart Van Assche, stable, Zhang, Yanmin, Ming Lei
On Mon, Jul 30, 2018 at 2:11 PM, xiao jin <jin.xiao@intel.com> wrote:
> 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")
> Signed-off-by: xiao jin <jin.xiao@intel.com>
> Cc: Ming Lei <ming.lei@redhat.com>
> Cc: Bart Van Assche <bart.vanassche@wdc.com>
> Cc: <stable@vger.kernel.org>
> ---
> block/blk-core.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/block/blk-core.c b/block/blk-core.c
> index b888175..52635e2 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -1072,6 +1072,7 @@ int blk_init_allocated_queue(struct request_queue *q)
> q->exit_rq_fn(q, q->fq->flush_rq);
> out_free_flush_queue:
> blk_free_flush_queue(q->fq);
> + q->fq = NULL;
> return -ENOMEM;
> }
> EXPORT_SYMBOL(blk_init_allocated_queue);
> --
> 1.7.9.5
>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Thanks,
Ming Lei
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] block: blk_init_allocated_queue() set q->fq as NULL in the fail case
2018-07-30 6:11 [PATCH] block: blk_init_allocated_queue() set q->fq as NULL in the fail case xiao jin
@ 2018-07-30 13:42 ` Bart Van Assche
2018-07-30 13:42 ` Bart Van Assche
2018-07-30 14:28 ` Jens Axboe
2 siblings, 0 replies; 5+ messages in thread
From: Bart Van Assche @ 2018-07-30 13:42 UTC (permalink / raw)
To: linux-kernel, linux-block, jin.xiao, axboe
Cc: yanmin.zhang, tom.leiming, stable, ming.lei
On Mon, 2018-07-30 at 14:11 +0800, xiao jin wrote:
> 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.
>=20
> Memory is allocated for q->fq in the blk_init_allocated=
F8-queue().
> If the elevator init function called with error return, it will
> run into the fail case to free the q->fq.
>=20
> Then the __blk_drain_queue() uses the same memory after=
the free
> of the q->fq, it will lead to the unpredictable event.
>=20
> The patch is to set q->fq as NULL in the fail case of
> blk_init_allocated_queue().
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] block: blk_init_allocated_queue() set q->fq as NULL in the fail case
@ 2018-07-30 13:42 ` Bart Van Assche
0 siblings, 0 replies; 5+ messages in thread
From: Bart Van Assche @ 2018-07-30 13:42 UTC (permalink / raw)
To: linux-kernel, linux-block, jin.xiao, axboe
Cc: yanmin.zhang, tom.leiming, stable, ming.lei
On Mon, 2018-07-30 at 14:11 +0800, xiao jin wrote:
> 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().
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] block: blk_init_allocated_queue() set q->fq as NULL in the fail case
2018-07-30 6:11 [PATCH] block: blk_init_allocated_queue() set q->fq as NULL in the fail case xiao jin
2018-07-30 12:06 ` Ming Lei
2018-07-30 13:42 ` Bart Van Assche
@ 2018-07-30 14:28 ` Jens Axboe
2 siblings, 0 replies; 5+ messages in thread
From: Jens Axboe @ 2018-07-30 14:28 UTC (permalink / raw)
To: xiao jin, linux-block, linux-kernel
Cc: tom.leiming, bart.vanassche, stable, yanmin.zhang, Ming Lei
On 7/30/18 12:11 AM, xiao jin wrote:
> 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().
Applied, thanks.
--
Jens Axboe
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2018-07-30 14:28 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-07-30 6:11 [PATCH] block: blk_init_allocated_queue() set q->fq as NULL in the fail case xiao jin
2018-07-30 12:06 ` Ming Lei
2018-07-30 13:42 ` Bart Van Assche
2018-07-30 13:42 ` Bart Van Assche
2018-07-30 14:28 ` Jens Axboe
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