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authorRoland Dreier <roland@purestorage.com>2018-01-11 13:38:15 -0800
committerSagi Grimberg <sagi@grimberg.me>2018-02-12 22:18:14 +0200
commit0a34e4668c508cbbc2d5ef2d9710b145e4c0b27d (patch)
tree53697e55ea1cfe7236ccac678c0a2ac6b103a9d9 /drivers/nvme
parentc3aedd225f8bcc3b3e61df074bc045b80542b38a (diff)
downloadlinux-0a34e4668c508cbbc2d5ef2d9710b145e4c0b27d.tar.bz2
nvme: Don't use a stack buffer for keep-alive command
In nvme_keep_alive() we pass a request with a pointer to an NVMe command on the stack into blk_execute_rq_nowait(). However, the block layer doesn't guarantee that the request is fully queued before blk_execute_rq_nowait() returns. If not, and the request is queued after nvme_keep_alive() returns, then we'll end up using stack memory that might have been overwritten to form the NVMe command we pass to hardware. Fix this by keeping a special command struct in the nvme_ctrl struct right next to the delayed work struct used for keep-alives. Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Diffstat (limited to 'drivers/nvme')
-rw-r--r--drivers/nvme/host/core.c8
-rw-r--r--drivers/nvme/host/nvme.h1
2 files changed, 4 insertions, 5 deletions
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 2fd8688cfa47..6d0490b477c9 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -796,13 +796,9 @@ static void nvme_keep_alive_end_io(struct request *rq, blk_status_t status)
static int nvme_keep_alive(struct nvme_ctrl *ctrl)
{
- struct nvme_command c;
struct request *rq;
- memset(&c, 0, sizeof(c));
- c.common.opcode = nvme_admin_keep_alive;
-
- rq = nvme_alloc_request(ctrl->admin_q, &c, BLK_MQ_REQ_RESERVED,
+ rq = nvme_alloc_request(ctrl->admin_q, &ctrl->ka_cmd, BLK_MQ_REQ_RESERVED,
NVME_QID_ANY);
if (IS_ERR(rq))
return PTR_ERR(rq);
@@ -834,6 +830,8 @@ void nvme_start_keep_alive(struct nvme_ctrl *ctrl)
return;
INIT_DELAYED_WORK(&ctrl->ka_work, nvme_keep_alive_work);
+ memset(&ctrl->ka_cmd, 0, sizeof(ctrl->ka_cmd));
+ ctrl->ka_cmd.common.opcode = nvme_admin_keep_alive;
schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
}
EXPORT_SYMBOL_GPL(nvme_start_keep_alive);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 27e31c00b306..0521e4707d1c 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -183,6 +183,7 @@ struct nvme_ctrl {
struct work_struct scan_work;
struct work_struct async_event_work;
struct delayed_work ka_work;
+ struct nvme_command ka_cmd;
struct work_struct fw_act_work;
/* Power saving configuration */