From: Shivam Kumar <kumar.shivam43666@gmail.com> stable inclusion from stable-v6.6.145 commit e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16831 CVE: CVE-2026-64534 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 4606467a75cfc16721937272ed29462a750b60c8 upstream. 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: Christoph Hellwig <hch@lst.de> Signed-off-by: Shivam Kumar <kumar.shivam43666@gmail.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Lu Chentao <luchentao1@huawei.com> --- drivers/nvme/target/tcp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c index 6ec6912b2b47..e530eebf0bf2 100644 --- a/drivers/nvme/target/tcp.c +++ b/drivers/nvme/target/tcp.c @@ -1288,11 +1288,12 @@ static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue) if (queue->data_digest && cmd->exp_ddgst != cmd->recv_ddgst) { pr_err("queue %d: cmd %d pdu (%d) data digest error: recv %#x expected %#x\n", 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)); - nvmet_req_uninit(&cmd->req); + if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED)) + nvmet_req_uninit(&cmd->req); nvmet_tcp_free_cmd_buffers(cmd); nvmet_tcp_fatal_error(queue); ret = -EPROTO; goto out; } -- 2.52.0