[RFC,v2,2/4] xfs: add verifier check for symlink with append/immutable flags
diff mbox

Message ID 20180510231359.16899-3-mcgrof@kernel.org
State New
Headers show

Commit Message

Luis Chamberlain May 10, 2018, 11:13 p.m. UTC
The Linux VFS does not allow a way to set append/immuttable attributes
to symlinks, this is just not possible. If this is detected we can
correct this with xfs_repair, so inform the user.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 fs/xfs/libxfs/xfs_symlink_remote.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Darrick J. Wong May 11, 2018, 2:20 a.m. UTC | #1
On Thu, May 10, 2018 at 04:13:57PM -0700, Luis R. Rodriguez wrote:
> The Linux VFS does not allow a way to set append/immuttable attributes
> to symlinks, this is just not possible. If this is detected we can
> correct this with xfs_repair, so inform the user.
> 
> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
> ---
>  fs/xfs/libxfs/xfs_symlink_remote.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/fs/xfs/libxfs/xfs_symlink_remote.c b/fs/xfs/libxfs/xfs_symlink_remote.c
> index 5ef5f354587e..42dd81ede3d6 100644
> --- a/fs/xfs/libxfs/xfs_symlink_remote.c
> +++ b/fs/xfs/libxfs/xfs_symlink_remote.c
> @@ -242,5 +242,10 @@ xfs_symlink_shortform_verify(
>  	/* We /did/ null-terminate the buffer, right? */
>  	if (*endp != 0)
>  		return __this_address;
> +
> +	/* Immutable and append flags are not allowed on symlinks */
> +	if (ip->i_d.di_flags & (XFS_DIFLAG_APPEND | XFS_DIFLAG_IMMUTABLE))
> +		return __this_address;

This belongs in xfs_dinode_verify so that it checks all symlinks, not
just the one shortform ones.

--D

> +
>  	return NULL;
>  }
> -- 
> 2.17.0
> 
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Patch
diff mbox

diff --git a/fs/xfs/libxfs/xfs_symlink_remote.c b/fs/xfs/libxfs/xfs_symlink_remote.c
index 5ef5f354587e..42dd81ede3d6 100644
--- a/fs/xfs/libxfs/xfs_symlink_remote.c
+++ b/fs/xfs/libxfs/xfs_symlink_remote.c
@@ -242,5 +242,10 @@  xfs_symlink_shortform_verify(
 	/* We /did/ null-terminate the buffer, right? */
 	if (*endp != 0)
 		return __this_address;
+
+	/* Immutable and append flags are not allowed on symlinks */
+	if (ip->i_d.di_flags & (XFS_DIFLAG_APPEND | XFS_DIFLAG_IMMUTABLE))
+		return __this_address;
+
 	return NULL;
 }