netdevsim: fix memory leak in nsim_drv_probe() when nsim_dev_resources_register() failed

If some items in nsim_dev_resources_register() fail, memory leak will
occur. The following is the memory leak information.

unreferenced object 0xffff888074c02600 (size 128):
  comm "echo", pid 8159, jiffies 4294945184 (age 493.530s)
  hex dump (first 32 bytes):
    40 47 ea 89 ff ff ff ff 01 00 00 00 00 00 00 00  @G..............
    ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ................
  backtrace:
    [<0000000011a31c98>] kmalloc_trace+0x22/0x60
    [<0000000027384c69>] devl_resource_register+0x144/0x4e0
    [<00000000a16db248>] nsim_drv_probe+0x37a/0x1260
    [<000000007d1f448c>] really_probe+0x20b/0xb10
    [<00000000c416848a>] __driver_probe_device+0x1b3/0x4a0
    [<00000000077e0351>] driver_probe_device+0x49/0x140
    [<0000000054f2465a>] __device_attach_driver+0x18c/0x2a0
    [<000000008538f359>] bus_for_each_drv+0x151/0x1d0
    [<0000000038e09747>] __device_attach+0x1c9/0x4e0
    [<00000000dd86e533>] bus_probe_device+0x1d5/0x280
    [<00000000839bea35>] device_add+0xae0/0x1cb0
    [<000000009c2abf46>] new_device_store+0x3b6/0x5f0
    [<00000000fb823d7f>] bus_attr_store+0x72/0xa0
    [<000000007acc4295>] sysfs_kf_write+0x106/0x160
    [<000000005f50cb4d>] kernfs_fop_write_iter+0x3a8/0x5a0
    [<0000000075eb41bf>] vfs_write+0x8f0/0xc80

Fixes: 37923ed6 ("netdevsim: Add simple FIB resource controller via devlink")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/netdevsim/dev.c

@@ -442,7 +442,7 @@ static int nsim_dev_resources_register(struct devlink *devlink)
 				     &params);
 	if (err) {
 		pr_err("Failed to register IPv4 top resource\n");
-		goto out;
+		goto err_out;
 	}
 
 	err = devl_resource_register(devlink, "fib", (u64)-1,
@@ -450,7 +450,7 @@ static int nsim_dev_resources_register(struct devlink *devlink)
 				     NSIM_RESOURCE_IPV4, &params);
 	if (err) {
 		pr_err("Failed to register IPv4 FIB resource\n");
-		return err;
+		goto err_out;
 	}
 
 	err = devl_resource_register(devlink, "fib-rules", (u64)-1,
@@ -458,7 +458,7 @@ static int nsim_dev_resources_register(struct devlink *devlink)
 				     NSIM_RESOURCE_IPV4, &params);
 	if (err) {
 		pr_err("Failed to register IPv4 FIB rules resource\n");
-		return err;
+		goto err_out;
 	}
 
 	/* Resources for IPv6 */
@@ -468,7 +468,7 @@ static int nsim_dev_resources_register(struct devlink *devlink)
 				     &params);
 	if (err) {
 		pr_err("Failed to register IPv6 top resource\n");
-		goto out;
+		goto err_out;
 	}
 
 	err = devl_resource_register(devlink, "fib", (u64)-1,
@@ -476,7 +476,7 @@ static int nsim_dev_resources_register(struct devlink *devlink)
 				     NSIM_RESOURCE_IPV6, &params);
 	if (err) {
 		pr_err("Failed to register IPv6 FIB resource\n");
-		return err;
+		goto err_out;
 	}
 
 	err = devl_resource_register(devlink, "fib-rules", (u64)-1,
@@ -484,7 +484,7 @@ static int nsim_dev_resources_register(struct devlink *devlink)
 				     NSIM_RESOURCE_IPV6, &params);
 	if (err) {
 		pr_err("Failed to register IPv6 FIB rules resource\n");
-		return err;
+		goto err_out;
 	}
 
 	/* Resources for nexthops */
@@ -492,8 +492,14 @@ static int nsim_dev_resources_register(struct devlink *devlink)
 				     NSIM_RESOURCE_NEXTHOPS,
 				     DEVLINK_RESOURCE_ID_PARENT_TOP,
 				     &params);
+	if (err) {
+		pr_err("Failed to register NEXTHOPS resource\n");
+		goto err_out;
+	}
+	return 0;
 
-out:
+err_out:
+	devl_resources_unregister(devlink);
 	return err;
 }