From a6ce7d7b4adaebc27ee7e78e5ecc378a1cfc221d Mon Sep 17 00:00:00 2001 From: Ziye Yang Date: Sat, 22 Aug 2020 00:48:10 +0800 Subject: [PATCH] nvmet-tcp: Fix NULL dereference when a connect data comes in h2cdata pdu When handling commands without in-capsule data, we assign the ttag assuming we already have the queue commands array allocated (based on the queue size information in the connect data payload). However if the connect itself did not send the connect data in-capsule we have yet to allocate the queue commands,and we will assign a bogus ttag and suffer a NULL dereference when we receive the corresponding h2cdata pdu. Fix this by checking if we already allocated commands before dereferencing it when handling h2cdata, if we didn't, its for sure a connect and we should use the preallocated connect command. Signed-off-by: Ziye Yang Signed-off-by: Sagi Grimberg --- drivers/nvme/target/tcp.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c index 9eda91162fe4..8e0d766d2722 100644 --- a/drivers/nvme/target/tcp.c +++ b/drivers/nvme/target/tcp.c @@ -160,6 +160,11 @@ static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd); static inline u16 nvmet_tcp_cmd_tag(struct nvmet_tcp_queue *queue, struct nvmet_tcp_cmd *cmd) { + if (unlikely(!queue->nr_cmds)) { + /* We didn't allocate cmds yet, send 0xffff */ + return USHRT_MAX; + } + return cmd - queue->cmds; } @@ -866,7 +871,10 @@ static int nvmet_tcp_handle_h2c_data_pdu(struct nvmet_tcp_queue *queue) struct nvme_tcp_data_pdu *data = &queue->pdu.data; struct nvmet_tcp_cmd *cmd; - cmd = &queue->cmds[data->ttag]; + if (likely(queue->nr_cmds)) + cmd = &queue->cmds[data->ttag]; + else + cmd = &queue->connect; if (le32_to_cpu(data->data_offset) != cmd->rbytes_done) { pr_err("ttag %u unexpected data offset %u (expected %u)\n",