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From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
To: linux-nvme@lists.infradead.org
Cc: kbusch@kernel.org, logang@deltatee.com, hch@lst.de,
	Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>,
	sagi@grimberg.me
Subject: [PATCH V2 09/12] nvmet: fix nvme module ref count Oops
Date: Mon, 31 Aug 2020 15:27:04 -0700	[thread overview]
Message-ID: <20200831222707.35611-10-chaitanya.kulkarni@wdc.com> (raw)
In-Reply-To: <20200831222707.35611-1-chaitanya.kulkarni@wdc.com>

In the passthru controller enable path current code doesn't take the
reference to the passthru ctrl module. Which produces following Oops :-

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

We fix that by taking a module ref count in nvme_dev_open() and release
that ref count in nvme_dev_release().

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
---
 drivers/nvme/host/core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index f82c6a283b15..c940f49a30bf 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3263,6 +3263,12 @@ static int nvme_dev_open(struct inode *inode, struct file *file)
 
 	file->private_data = ctrl;
 	nvme_get_ctrl(ctrl);
+	if (!try_module_get(ctrl->ops->module)) {
+		pr_err("try_module_get failed for cntlid 0x%x\n", ctrl->cntlid);
+		nvme_put_ctrl(ctrl);
+		return -EINVAL;
+	}
+
 	return 0;
 }
 
@@ -3271,6 +3277,7 @@ 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;
 }
-- 
2.22.1


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  parent reply	other threads:[~2020-08-31 22:28 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-31 22:26 [PATCH V2 00/12] nvmet: passthru fixes and improvements Chaitanya Kulkarni
2020-08-31 22:26 ` [PATCH V2 01/12] nvme-core: annotate nvme_alloc_request() Chaitanya Kulkarni
2020-09-01  1:56   ` Baolin Wang
2020-09-01 17:21     ` Sagi Grimberg
2020-09-01 21:16       ` Chaitanya Kulkarni
2020-09-02  3:28       ` Chaitanya Kulkarni
2020-09-02 22:02       ` Chaitanya Kulkarni
2020-09-03 16:17   ` Christoph Hellwig
2020-09-03 19:40     ` Chaitanya Kulkarni
2020-09-08  8:57       ` Christoph Hellwig
2020-08-31 22:26 ` [PATCH V2 02/12] nvmet: for pt I/O commands use likely for ns check Chaitanya Kulkarni
2020-09-03 16:18   ` Christoph Hellwig
2020-09-03 18:21     ` Chaitanya Kulkarni
2020-08-31 22:26 ` [PATCH V2 03/12] nvmet: use consistent type with id->nlbaf Chaitanya Kulkarni
2020-09-01 15:55   ` Keith Busch
2020-09-01 21:17     ` Chaitanya Kulkarni
2020-09-01 21:31       ` Logan Gunthorpe
2020-09-01 22:03       ` Keith Busch
2020-08-31 22:26 ` [PATCH V2 04/12] nvmet: use consistent type for op_flag Chaitanya Kulkarni
2020-09-03 16:20   ` Christoph Hellwig
2020-09-03 18:35     ` Chaitanya Kulkarni
2020-08-31 22:27 ` [PATCH V2 05/12] nvmet: use unlikely for uncommon commands Chaitanya Kulkarni
2020-09-03 16:20   ` Christoph Hellwig
2020-09-03 18:37     ` Chaitanya Kulkarni
2020-08-31 22:27 ` [PATCH V2 06/12] nvmet: remove op_flags for write commands Chaitanya Kulkarni
2020-08-31 22:27 ` [PATCH V2 07/12] nvmet: decouple nvme_ctrl_get_by_path() Chaitanya Kulkarni
2020-09-01 17:00   ` Logan Gunthorpe
2020-08-31 22:27 ` [PATCH V2 08/12] nvmet: move get/put ctrl into dev open/release Chaitanya Kulkarni
2020-09-01 17:02   ` Logan Gunthorpe
2020-09-01 17:18     ` Sagi Grimberg
2020-09-02  0:31       ` Chaitanya Kulkarni
2020-09-03 16:21       ` Christoph Hellwig
2020-09-03 18:22         ` Chaitanya Kulkarni
2020-08-31 22:27 ` Chaitanya Kulkarni [this message]
2020-09-01 17:23   ` [PATCH V2 09/12] nvmet: fix nvme module ref count Oops Logan Gunthorpe
2020-08-31 22:27 ` [PATCH V2 10/12] block: move blk_rq_bio_prep() to linux/blk-mq.h Chaitanya Kulkarni
2020-08-31 22:27 ` [PATCH V2 11/12] nvmet: use minimized version of blk_rq_append_bio Chaitanya Kulkarni
2020-09-03 16:23   ` Christoph Hellwig
2020-09-03 18:23     ` Chaitanya Kulkarni
2020-08-31 22:27 ` [PATCH V2 12/12] nvmet: use inline bio for passthru fast path Chaitanya Kulkarni
2020-09-01 17:29   ` Logan Gunthorpe
2020-09-02  0:39     ` Chaitanya Kulkarni
2020-09-02 15:41       ` Logan Gunthorpe
2020-09-02 21:04         ` Chaitanya Kulkarni

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