From: Varun Prakash <varun@chelsio.com> stable inclusion from stable-5.10.77 commit c63d7f2ca99a2e2a9b62d42bffa0ccec407b91b0 bugzilla: 185677 https://gitee.com/openeuler/kernel/issues/I4IAP7 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit ce7723e9cdae4eb3030da082876580f4b2dc0861 upstream. With commit db5ad6b7f8cd ("nvme-tcp: try to send request in queue_rq context") r2t and response PDU can get processed while send function is executing. Current data digest send code uses req->offset after kernel_sendmsg(), this creates a race condition where req->offset gets reset before it is used in send function. This can happen in two cases - 1. Target sends r2t PDU which resets req->offset. 2. Target send response PDU which completes the req and then req is used for a new command, nvme_tcp_setup_cmd_pdu() resets req->offset. Fix this by storing req->offset in a local variable and using this local variable after kernel_sendmsg(). Fixes: db5ad6b7f8cd ("nvme-tcp: try to send request in queue_rq context") Signed-off-by: Varun Prakash <varun@chelsio.com> Reviewed-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> --- drivers/nvme/host/tcp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index afef377424c4..e99d43989418 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -1037,6 +1037,7 @@ static int nvme_tcp_try_send_data_pdu(struct nvme_tcp_request *req) static int nvme_tcp_try_send_ddgst(struct nvme_tcp_request *req) { struct nvme_tcp_queue *queue = req->queue; + size_t offset = req->offset; int ret; struct msghdr msg = { .msg_flags = MSG_DONTWAIT }; struct kvec iov = { @@ -1053,7 +1054,7 @@ static int nvme_tcp_try_send_ddgst(struct nvme_tcp_request *req) if (unlikely(ret <= 0)) return ret; - if (req->offset + ret == NVME_TCP_DIGEST_LENGTH) { + if (offset + ret == NVME_TCP_DIGEST_LENGTH) { nvme_tcp_done_send_req(queue); return 1; } -- 2.20.1