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

From: Josef Bacik
Date: Thu Apr 26 2012 - 14:26:12 EST


On Thu, Apr 26, 2012 at 06:36:56PM +0200, Jim Meyering wrote:
>
> 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@xxxxxxxxxx>
> ---
> 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

This didn't merge quite right onto btrfs-next btw so I've fixed it up manually
(but left the log/author/signed off intact). Thanks,

Josef
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