Commit 4606467a authored by Shivam Kumar's avatar Shivam Kumar Committed by Keith Busch
Browse files

nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path 



In nvmet_tcp_try_recv_ddgst(), when a data digest mismatch is detected,
nvmet_req_uninit() is called unconditionally. However, if the command
arrived via the nvmet_tcp_handle_req_failure() path, nvmet_req_init()
had returned false and percpu_ref_tryget_live() was never executed. The
unconditional percpu_ref_put() inside nvmet_req_uninit() then causes a
refcount underflow, leading to a WARNING in
percpu_ref_switch_to_atomic_rcu, a use-after-free diagnostic, and
eventually a permanent workqueue deadlock.

Check cmd->flags & NVMET_TCP_F_INIT_FAILED before calling
nvmet_req_uninit(), matching the existing pattern in
nvmet_tcp_execute_request().

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarShivam Kumar <kumar.shivam43666@gmail.com>
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
parent e9b004ff

drivers/nvme/target/tcp.c

+2 −1
Original line number Diff line number Diff line
@@ -1310,6 +1310,7 @@ static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue) 
			queue->idx, cmd->req.cmd->common.command_id,

			queue->pdu.cmd.hdr.type, le32_to_cpu(cmd->recv_ddgst),

			le32_to_cpu(cmd->exp_ddgst));

		if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED))

			nvmet_req_uninit(&cmd->req);

		nvmet_tcp_free_cmd_buffers(cmd);

		nvmet_tcp_fatal_error(queue);