From 6173a77b7e9d3e202bdb9897b23f2a8afe7bf286 Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Mon, 6 Mar 2023 10:13:13 +0900 Subject: 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: a07b4970f464 ("nvmet: add a generic NVMe target") Signed-off-by: Damien Le Moal Reviewed-by: Chaitanya Kulkarni Signed-off-by: Christoph Hellwig --- drivers/nvme/target/core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/nvme') diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c index f66ed13d7c11..3935165048e7 100644 --- a/drivers/nvme/target/core.c +++ b/drivers/nvme/target/core.c @@ -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); -- cgit v1.2.3