[PATCH AUTOSEL 4.19 02/15] nvme-rdma: Avoid double freeing of async event data

From: Sasha Levin
Date: Thu Mar 26 2020 - 19:27:13 EST


From: Prabhath Sajeepa <psajeepa@xxxxxxxxxxxxxxx>

[ Upstream commit 9134ae2a2546cb96abddcd4469a79c77ee3a4480 ]

The timeout of identify cmd, which is invoked as part of admin queue
creation, can result in freeing of async event data both in
nvme_rdma_timeout handler and error handling path of
nvme_rdma_configure_admin queue thus causing NULL pointer reference.
Call Trace:
? nvme_rdma_setup_ctrl+0x223/0x800 [nvme_rdma]
nvme_rdma_create_ctrl+0x2ba/0x3f7 [nvme_rdma]
nvmf_dev_write+0xa54/0xcc6 [nvme_fabrics]
__vfs_write+0x1b/0x40
vfs_write+0xb2/0x1b0
ksys_write+0x61/0xd0
__x64_sys_write+0x1a/0x20
do_syscall_64+0x60/0x1e0
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reviewed-by: Roland Dreier <roland@xxxxxxxxxxxxxxx>
Reviewed-by: Max Gurtovoy <maxg@xxxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Prabhath Sajeepa <psajeepa@xxxxxxxxxxxxxxx>
Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/nvme/host/rdma.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index e4f167e35353f..9711bfbdf4316 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -815,9 +815,11 @@ static int nvme_rdma_configure_admin_queue(struct nvme_rdma_ctrl *ctrl,
if (new)
nvme_rdma_free_tagset(&ctrl->ctrl, ctrl->ctrl.admin_tagset);
out_free_async_qe:
- nvme_rdma_free_qe(ctrl->device->dev, &ctrl->async_event_sqe,
- sizeof(struct nvme_command), DMA_TO_DEVICE);
- ctrl->async_event_sqe.data = NULL;
+ if (ctrl->async_event_sqe.data) {
+ nvme_rdma_free_qe(ctrl->device->dev, &ctrl->async_event_sqe,
+ sizeof(struct nvme_command), DMA_TO_DEVICE);
+ ctrl->async_event_sqe.data = NULL;
+ }
out_free_queue:
nvme_rdma_free_queue(&ctrl->queues[0]);
return error;
--
2.20.1