diff mbox series

btrfs: scrub: reject unsupported scrub flags

Message ID df2418c0b26dc12913d5f542caf977bc3d1f28b2.1680757087.git.wqu@suse.com (mailing list archive)
State New, archived
Headers show
Series btrfs: scrub: reject unsupported scrub flags | expand

Commit Message

Qu Wenruo April 6, 2023, 5 a.m. UTC
Since the introduction of scrub interface, the only flag that we support
is BTRFS_SCRUB_READONLY.

Thus there is no sanity checks, if there are some undefined flags passed
in, we just ignore them.

This is problematic if we want to introduce new scrub flags, as we have
no way to determine if such flags are supported.

Thus this patch would address the problem by introducing a check for the
flags, and if unsupported flags are set, return -EOPNOTSUPP to inform
the user space.

This check should be backported for all supported kernels before any new
scrub flags are introduced.

CC: stable@vger.kernel.org
Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/ioctl.c           | 5 +++++
 include/uapi/linux/btrfs.h | 1 +
 2 files changed, 6 insertions(+)

Comments

Anand Jain April 6, 2023, 5:36 a.m. UTC | #1
On 4/6/23 13:00, Qu Wenruo wrote:
> Since the introduction of scrub interface, the only flag that we support
> is BTRFS_SCRUB_READONLY.
> 
> Thus there is no sanity checks, if there are some undefined flags passed
> in, we just ignore them.
> 
> This is problematic if we want to introduce new scrub flags, as we have
> no way to determine if such flags are supported.
> 
> Thus this patch would address the problem by introducing a check for the
> flags, and if unsupported flags are set, return -EOPNOTSUPP to inform
> the user space.
> 
> This check should be backported for all supported kernels before any new
> scrub flags are introduced.
> 
> CC: stable@vger.kernel.org
> Signed-off-by: Qu Wenruo <wqu@suse.com>

Reviewed-by: Anand Jain <anand.jain@oracle.com>


> ---
>   fs/btrfs/ioctl.c           | 5 +++++
>   include/uapi/linux/btrfs.h | 1 +
>   2 files changed, 6 insertions(+)
> 
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index ba769a1eb87a..25833b4eeaf5 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -3161,6 +3161,11 @@ static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
>   	if (IS_ERR(sa))
>   		return PTR_ERR(sa);
>   
> +	if (sa->flags & ~BTRFS_SCRUB_SUPPORTED_FLAGS) {
> +		ret = -EOPNOTSUPP;
> +		goto out;
> +	}
> +
>   	if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
>   		ret = mnt_want_write_file(file);
>   		if (ret)
> diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
> index ada0a489bf2b..dbb8b96da50d 100644
> --- a/include/uapi/linux/btrfs.h
> +++ b/include/uapi/linux/btrfs.h
> @@ -187,6 +187,7 @@ struct btrfs_scrub_progress {
>   };
>   
>   #define BTRFS_SCRUB_READONLY	1
> +#define BTRFS_SCRUB_SUPPORTED_FLAGS	(BTRFS_SCRUB_READONLY)
>   struct btrfs_ioctl_scrub_args {
>   	__u64 devid;				/* in */
>   	__u64 start;				/* in */
David Sterba April 6, 2023, 3:01 p.m. UTC | #2
On Thu, Apr 06, 2023 at 01:00:34PM +0800, Qu Wenruo wrote:
> Since the introduction of scrub interface, the only flag that we support
> is BTRFS_SCRUB_READONLY.
> 
> Thus there is no sanity checks, if there are some undefined flags passed
> in, we just ignore them.
> 
> This is problematic if we want to introduce new scrub flags, as we have
> no way to determine if such flags are supported.
> 
> Thus this patch would address the problem by introducing a check for the
> flags, and if unsupported flags are set, return -EOPNOTSUPP to inform
> the user space.
> 
> This check should be backported for all supported kernels before any new
> scrub flags are introduced.
> 
> CC: stable@vger.kernel.org
> Signed-off-by: Qu Wenruo <wqu@suse.com>

Added to misc-next, thanks.
diff mbox series

Patch

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index ba769a1eb87a..25833b4eeaf5 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3161,6 +3161,11 @@  static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
 	if (IS_ERR(sa))
 		return PTR_ERR(sa);
 
+	if (sa->flags & ~BTRFS_SCRUB_SUPPORTED_FLAGS) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
 	if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
 		ret = mnt_want_write_file(file);
 		if (ret)
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index ada0a489bf2b..dbb8b96da50d 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -187,6 +187,7 @@  struct btrfs_scrub_progress {
 };
 
 #define BTRFS_SCRUB_READONLY	1
+#define BTRFS_SCRUB_SUPPORTED_FLAGS	(BTRFS_SCRUB_READONLY)
 struct btrfs_ioctl_scrub_args {
 	__u64 devid;				/* in */
 	__u64 start;				/* in */