Commit 8c1624b6 authored by Sagi Grimberg's avatar Sagi Grimberg Committed by Keith Busch
Browse files

nvme-tcp: fix possible UAF in nvme_tcp_poll 



nvme_tcp_poll() may race with the send path error handler because
it may complete the request while it is actively being polled for
completion, resulting in a UAF panic [1]:

We should make sure to stop polling when we see an error when
trying to read from the socket. Hence make sure to propagate the
error so that the block layer breaks the polling cycle.

[1]:
--
[35665.692310] nvme nvme2: failed to send request -13
[35665.702265] nvme nvme2: unsupported pdu type (3)
[35665.702272] BUG: kernel NULL pointer dereference, address: 0000000000000000
[35665.702542] nvme nvme2: queue 1 receive failed:  -22
[35665.703209] #PF: supervisor write access in kernel mode
[35665.703213] #PF: error_code(0x0002) - not-present page
[35665.703214] PGD 8000003801cce067 P4D 8000003801cce067 PUD 37e6f79067 PMD 0
[35665.703220] Oops: 0002 [#1] SMP PTI
[35665.703658] nvme nvme2: starting error recovery
[35665.705809] Hardware name: Inspur aaabbb/YZMB-00882-104, BIOS 4.1.26 09/22/2022
[35665.705812] Workqueue: kblockd blk_mq_requeue_work
[35665.709172] RIP: 0010:_raw_spin_lock+0xc/0x30
[35665.715788] Call Trace:
[35665.716201]  <TASK>
[35665.716613]  ? show_trace_log_lvl+0x1c1/0x2d9
[35665.717049]  ? show_trace_log_lvl+0x1c1/0x2d9
[35665.717457]  ? blk_mq_request_bypass_insert+0x2c/0xb0
[35665.717950]  ? __die_body.cold+0x8/0xd
[35665.718361]  ? page_fault_oops+0xac/0x140
[35665.718749]  ? blk_mq_start_request+0x30/0xf0
[35665.719144]  ? nvme_tcp_queue_rq+0xc7/0x170 [nvme_tcp]
[35665.719547]  ? exc_page_fault+0x62/0x130
[35665.719938]  ? asm_exc_page_fault+0x22/0x30
[35665.720333]  ? _raw_spin_lock+0xc/0x30
[35665.720723]  blk_mq_request_bypass_insert+0x2c/0xb0
[35665.721101]  blk_mq_requeue_work+0xa5/0x180
[35665.721451]  process_one_work+0x1e8/0x390
[35665.721809]  worker_thread+0x53/0x3d0
[35665.722159]  ? process_one_work+0x390/0x390
[35665.722501]  kthread+0x124/0x150
[35665.722849]  ? set_kthread_struct+0x50/0x50
[35665.723182]  ret_from_fork+0x1f/0x30

Reported-by: default avatarZhang Guanghui <zhang.guanghui@cestc.cn>
Signed-off-by: default avatarSagi Grimberg <sagi@grimberg.me>
Reviewed-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
parent 70550442

drivers/nvme/host/tcp.c

+3 −2
Original line number Diff line number Diff line
@@ -2699,6 +2699,7 @@ static int nvme_tcp_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) 
{

	struct nvme_tcp_queue *queue = hctx->driver_data;

	struct sock *sk = queue->sock->sk;

	int ret;



	if (!test_bit(NVME_TCP_Q_LIVE, &queue->flags))

		return 0;
@@ -2706,9 +2707,9 @@ static int nvme_tcp_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) 
	set_bit(NVME_TCP_Q_POLLING, &queue->flags);

	if (sk_can_busy_loop(sk) && skb_queue_empty_lockless(&sk->sk_receive_queue))

		sk_busy_loop(sk, true);

	nvme_tcp_try_recv(queue);

	ret = nvme_tcp_try_recv(queue);

	clear_bit(NVME_TCP_Q_POLLING, &queue->flags);

	return queue->nr_cqe;

	return ret < 0 ? ret : queue->nr_cqe;

}



static int nvme_tcp_get_address(struct nvme_ctrl *ctrl, char *buf, int size)