[PATCH 3.18.y 4.4.y 4.9.y] 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 Signed-off-by: Alessio Balsini balsini@android.com --- block/blk-core.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/block/blk-core.c b/block/blk-core.c index 50d77c90070d..7662f97dded6 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -870,6 +870,7 @@ blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn,
fail: blk_free_flush_queue(q->fq); + q->fq = NULL; return NULL; } EXPORT_SYMBOL(blk_init_allocated_queue);
On Thu, Aug 08, 2019 at 03:28:19AM +0100, Alessio Balsini wrote:
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 Signed-off-by: Alessio Balsini balsini@android.com
block/blk-core.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/block/blk-core.c b/block/blk-core.c index 50d77c90070d..7662f97dded6 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -870,6 +870,7 @@ blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn, fail: blk_free_flush_queue(q->fq);
- q->fq = NULL; return NULL;
} EXPORT_SYMBOL(blk_init_allocated_queue); -- 2.22.0.770.g0f2c4a37fd-goog
Guenter sent this backport a day before you did, so I took his version and added your s-o-b to it.
thanks,
greg k-h
Oops, thanks!
On Thu, Aug 8, 2019 at 2:00 AM Greg KH gregkh@linuxfoundation.org wrote:
On Thu, Aug 08, 2019 at 03:28:19AM +0100, Alessio Balsini wrote:
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 Signed-off-by: Alessio Balsini balsini@android.com
block/blk-core.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/block/blk-core.c b/block/blk-core.c index 50d77c90070d..7662f97dded6 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -870,6 +870,7 @@ blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn,
fail: blk_free_flush_queue(q->fq);
q->fq = NULL; return NULL;} EXPORT_SYMBOL(blk_init_allocated_queue); -- 2.22.0.770.g0f2c4a37fd-goog
Guenter sent this backport a day before you did, so I took his version and added your s-o-b to it.
thanks,
greg k-h
linux-stable-mirror@lists.linaro.org
-
Alessio Balsini -
Greg KH