From a8bc2260cd075c854beee9443499389fdf85807e Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Mon, 6 Mar 2023 10:13:13 +0900 Subject: [PATCH] nvmet: avoid potential UAF in nvmet_req_complete() [ Upstream commit 6173a77b7e9d3e202bdb9897b23f2a8afe7bf286 ] 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: ffb9618ad11f ("nvmet: add a generic NVMe target") Signed-off-by: Damien Le Moal Reviewed-by: Chaitanya Kulkarni Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin --- drivers/nvme/target/core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c index ff206faae775c..d109333b95b81 100644 --- a/drivers/nvme/target/core.c +++ b/drivers/nvme/target/core.c @@ -728,8 +728,10 @@ 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); -- 2.39.5