nvmet: avoid potential UAF in nvmet_req_complete()

An nvme target ->queue_response() operation implementation may free the
request passed as argument. Such implementation potentially could result
in a use after free of the request pointer when percpu_ref_put() is
called in nvmet_req_complete().

Avoid such problem by using a local variable to save the sq pointer
before calling __nvmet_req_complete(), thus avoiding dereferencing the
req pointer after that function call.

Fixes: a07b4970f4 ("nvmet: add a generic NVMe target")
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Damien Le Moal 2023-03-06 10:13:13 +09:00 committed by Christoph Hellwig
parent 8e19b87cfc
commit 6173a77b7e

View File

@ -756,8 +756,10 @@ static void __nvmet_req_complete(struct nvmet_req *req, u16 status)
void nvmet_req_complete(struct nvmet_req *req, u16 status)
{
struct nvmet_sq *sq = req->sq;
__nvmet_req_complete(req, status);
percpu_ref_put(&req->sq->ref);
percpu_ref_put(&sq->ref);
}
EXPORT_SYMBOL_GPL(nvmet_req_complete);