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From: Ilya Dryomov <idryomov@gmail.com>
To: ceph-devel@vger.kernel.org
Cc: Dongsheng Yang <dongsheng.yang@easystack.cn>
Subject: [PATCH 2/3] rbd: harden get_lock_owner_info() a bit
Date: Tue, 25 Jul 2023 06:35:55 +0200	[thread overview]
Message-ID: <20230725043559.123889-3-idryomov@gmail.com> (raw)
In-Reply-To: <20230725043559.123889-1-idryomov@gmail.com>

- we want the exclusive lock type, so test for it directly
- use sscanf() to actually parse the lock cookie and avoid admitting
  invalid handles
- bail if locker has a blank address

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index dca6c1e5f6bc..94629e826369 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -3862,10 +3862,9 @@ static struct ceph_locker *get_lock_owner_info(struct rbd_device *rbd_dev)
 	u32 num_lockers;
 	u8 lock_type;
 	char *lock_tag;
+	u64 handle;
 	int ret;
 
-	dout("%s rbd_dev %p\n", __func__, rbd_dev);
-
 	ret = ceph_cls_lock_info(osdc, &rbd_dev->header_oid,
 				 &rbd_dev->header_oloc, RBD_LOCK_NAME,
 				 &lock_type, &lock_tag, &lockers, &num_lockers);
@@ -3886,18 +3885,28 @@ static struct ceph_locker *get_lock_owner_info(struct rbd_device *rbd_dev)
 		goto err_busy;
 	}
 
-	if (lock_type == CEPH_CLS_LOCK_SHARED) {
-		rbd_warn(rbd_dev, "shared lock type detected");
+	if (lock_type != CEPH_CLS_LOCK_EXCLUSIVE) {
+		rbd_warn(rbd_dev, "incompatible lock type detected");
 		goto err_busy;
 	}
 
 	WARN_ON(num_lockers != 1);
-	if (strncmp(lockers[0].id.cookie, RBD_LOCK_COOKIE_PREFIX,
-		    strlen(RBD_LOCK_COOKIE_PREFIX))) {
+	ret = sscanf(lockers[0].id.cookie, RBD_LOCK_COOKIE_PREFIX " %llu",
+		     &handle);
+	if (ret != 1) {
 		rbd_warn(rbd_dev, "locked by external mechanism, cookie %s",
 			 lockers[0].id.cookie);
 		goto err_busy;
 	}
+	if (ceph_addr_is_blank(&lockers[0].info.addr)) {
+		rbd_warn(rbd_dev, "locker has a blank address");
+		goto err_busy;
+	}
+
+	dout("%s rbd_dev %p got locker %s%llu@%pISpc/%u handle %llu\n",
+	     __func__, rbd_dev, ENTITY_NAME(lockers[0].id.name),
+	     &lockers[0].info.addr.in_addr,
+	     le32_to_cpu(lockers[0].info.addr.nonce), handle);
 
 out:
 	kfree(lock_tag);
-- 
2.41.0


  parent reply	other threads:[~2023-07-25  4:36 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-25  4:35 [PATCH 0/3] rbd: reduce the potential for erroneous blocklisting Ilya Dryomov
2023-07-25  4:35 ` [PATCH 1/3] rbd: make get_lock_owner_info() return a single locker or NULL Ilya Dryomov
2023-07-25  4:35 ` Ilya Dryomov [this message]
2023-07-25  4:35 ` [PATCH 3/3] rbd: retrieve and check lock owner twice before blocklisting Ilya Dryomov

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