[PATCH 4/6] misc: ibmvmc: initialize HMC state before device registration

[Jiale Yao]

misc_register() exposes the IBM VMC device before the HMC state and
spinlocks are initialized. A userspace operation racing module
initialization can therefore access an HMC through an uninitialized
spinlock.

Initialize all HMC state before registering the misc device.

Fixes: 0eca353e7ae7 ("misc: IBM Virtual Management Channel Driver (VMC)")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jiale Yao <yaojiale02@xxxxxxx>
---
 drivers/misc/ibmvmc.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/misc/ibmvmc.c b/drivers/misc/ibmvmc.c
index 6afef0788b90..d03aeb8dea8f 100644
--- a/drivers/misc/ibmvmc.c
+++ b/drivers/misc/ibmvmc.c
@@ -2366,14 +2366,6 @@ static int __init ibmvmc_module_init(void)
 	ibmvmc.state = ibmvmc_state_initial;
 	pr_info("ibmvmc: version %s\n", IBMVMC_DRIVER_VERSION);
 
-	rc = misc_register(&ibmvmc_miscdev);
-	if (rc) {
-		pr_err("ibmvmc: misc registration failed\n");
-		goto misc_register_failed;
-	}
-	pr_info("ibmvmc: node %d:%d\n", MISC_MAJOR,
-		ibmvmc_miscdev.minor);
-
 	/* Initialize data structures */
 	memset(hmcs, 0, sizeof(struct ibmvmc_hmc) * MAX_HMCS);
 	for (i = 0; i < MAX_HMCS; i++) {
@@ -2383,6 +2375,14 @@ static int __init ibmvmc_module_init(void)
 			hmcs[i].queue_outbound_msgs[j] = VMC_INVALID_BUFFER_ID;
 	}
 
+	rc = misc_register(&ibmvmc_miscdev);
+	if (rc) {
+		pr_err("ibmvmc: misc registration failed\n");
+		goto misc_register_failed;
+	}
+	pr_info("ibmvmc: node %d:%d\n", MISC_MAJOR,
+		ibmvmc_miscdev.minor);
+
 	/* Sanity check module parms */
 	ibmvmc_scrub_module_parms();
 
-- 
2.34.1