[PATCH AUTOSEL 4.19 05/11] nvme-core: get/put ctrl and transport module in nvme_dev_open/release()

[PATCH AUTOSEL 4.19 05/11] nvme-core: get/put ctrl and transport module in nvme_dev_open/release()

[Sasha Levin]

From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>

[ Upstream commit 52a3974feb1a3eec25d8836d37a508b67b0a9cd0 ]

Get and put the reference to the ctrl in the nvme_dev_open() and
nvme_dev_release() before and after module get/put for ctrl in char
device file operations.

Introduce char_dev relase function, get/put the controller and module
which allows us to fix the potential Oops which can be easily reproduced
with a passthru ctrl (although the problem also exists with pure user
access):

Entering kdb (current=0xffff8887f8290000, pid 3128) on processor 30 Oops: (null)
due to oops @ 0xffffffffa01019ad
CPU: 30 PID: 3128 Comm: bash Tainted: G        W  OE     5.8.0-rc4nvme-5.9+ #35
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.4
RIP: 0010:nvme_free_ctrl+0x234/0x285 [nvme_core]
Code: 57 10 a0 e8 73 bf 02 e1 ba 3d 11 00 00 48 c7 c6 98 33 10 a0 48 c7 c7 1d 57 10 a0 e8 5b bf 02 e1 8
RSP: 0018:ffffc90001d63de0 EFLAGS: 00010246
RAX: ffffffffa05c0440 RBX: ffff8888119e45a0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff8888177e9550 RDI: ffff8888119e43b0
RBP: ffff8887d4768000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffc90001d63c90 R12: ffff8888119e43b0
R13: ffff8888119e5108 R14: dead000000000100 R15: ffff8888119e5108
FS:  00007f1ef27b0740(0000) GS:ffff888817600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffa05c0470 CR3: 00000007f6bee000 CR4: 00000000003406e0
Call Trace:
 device_release+0x27/0x80
 kobject_put+0x98/0x170
 nvmet_passthru_ctrl_disable+0x4a/0x70 [nvmet]
 nvmet_passthru_enable_store+0x4c/0x90 [nvmet]
 configfs_write_file+0xe6/0x150
 vfs_write+0xba/0x1e0
 ksys_write+0x5f/0xe0
 do_syscall_64+0x52/0xb0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f1ef1eb2840
Code: Bad RIP value.
RSP: 002b:00007fffdbff0eb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f1ef1eb2840
RDX: 0000000000000002 RSI: 00007f1ef27d2000 RDI: 0000000000000001
RBP: 00007f1ef27d2000 R08: 000000000000000a R09: 00007f1ef27b0740
R10: 0000000000000001 R11: 0000000000000246 R12: 00007f1ef2186400
R13: 0000000000000002 R14: 0000000000000001 R15: 0000000000000000

With this patch fix we take the module ref count in nvme_dev_open() and
release that ref count in newly introduced nvme_dev_release().

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/nvme/host/core.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 0d60f2f8f3eec..c6c61130f50a0 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2608,10 +2608,24 @@ static int nvme_dev_open(struct inode *inode, struct file *file)
 		return -EWOULDBLOCK;
 	}
 
+	nvme_get_ctrl(ctrl);
+	if (!try_module_get(ctrl->ops->module))
+		return -EINVAL;
+
 	file->private_data = ctrl;
 	return 0;
 }
 
+static int nvme_dev_release(struct inode *inode, struct file *file)
+{
+	struct nvme_ctrl *ctrl =
+		container_of(inode->i_cdev, struct nvme_ctrl, cdev);
+
+	module_put(ctrl->ops->module);
+	nvme_put_ctrl(ctrl);
+	return 0;
+}
+
 static int nvme_dev_user_cmd(struct nvme_ctrl *ctrl, void __user *argp)
 {
 	struct nvme_ns *ns;
@@ -2672,6 +2686,7 @@ static long nvme_dev_ioctl(struct file *file, unsigned int cmd,
 static const struct file_operations nvme_dev_fops = {
 	.owner		= THIS_MODULE,
 	.open		= nvme_dev_open,
+	.release	= nvme_dev_release,
 	.unlocked_ioctl	= nvme_dev_ioctl,
 	.compat_ioctl	= nvme_dev_ioctl,
 };
-- 
2.25.1


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[PATCH AUTOSEL 4.19 11/11] nvme-fc: fail new connections to a deleted host or remote port

[Sasha Levin]

From: James Smart <james.smart@broadcom.com>

[ Upstream commit 9e0e8dac985d4bd07d9e62922b9d189d3ca2fccf ]

The lldd may have made calls to delete a remote port or local port and
the delete is in progress when the cli then attempts to create a new
controller. Currently, this proceeds without error although it can't be
very successful.

Fix this by validating that both the host port and remote port are
present when a new controller is to be created.

Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/nvme/host/fc.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 73db32f97abf3..ed88d50217724 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -3294,12 +3294,14 @@ nvme_fc_create_ctrl(struct device *dev, struct nvmf_ctrl_options *opts)
 	spin_lock_irqsave(&nvme_fc_lock, flags);
 	list_for_each_entry(lport, &nvme_fc_lport_list, port_list) {
 		if (lport->localport.node_name != laddr.nn ||
-		    lport->localport.port_name != laddr.pn)
+		    lport->localport.port_name != laddr.pn ||
+		    lport->localport.port_state != FC_OBJSTATE_ONLINE)
 			continue;
 
 		list_for_each_entry(rport, &lport->endp_list, endp_list) {
 			if (rport->remoteport.node_name != raddr.nn ||
-			    rport->remoteport.port_name != raddr.pn)
+			    rport->remoteport.port_name != raddr.pn ||
+			    rport->remoteport.port_state != FC_OBJSTATE_ONLINE)
 				continue;
 
 			/* if fail to get reference fall through. Will error */
-- 
2.25.1


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