[PATCH] Btrfs: NUL-terminate path buffer in DEV_INFO ioctl result

[Jim Meyering <jim@meyering.net>]

A device with name of length BTRFS_DEVICE_PATH_NAME_MAX or longer
would not be NUL-terminated in the DEV_INFO ioctl result buffer.

Signed-off-by: Jim Meyering <meyering@redhat.com>
---
 fs/btrfs/ioctl.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 18cc23d..1578676 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2258,16 +2258,17 @@ static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
 		goto out;
 	}

 	di_args->devid = dev->devid;
 	di_args->bytes_used = dev->bytes_used;
 	di_args->total_bytes = dev->total_bytes;
 	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
 	strncpy(di_args->path, dev->name, sizeof(di_args->path));
+	di_args->path[sizeof(di_args->path) - 1] = 0;

 out:
 	if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
 		ret = -EFAULT;

 	kfree(di_args);
 	return ret;
 }
--
1.7.10.336.gc5e31