On Wed, Dec 13, 2017 at 03:59:01PM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> Create a function to check the structure of short form symlink targets.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
> fs/xfs/libxfs/xfs_shared.h | 1 +
> fs/xfs/libxfs/xfs_symlink_remote.c | 36 ++++++++++++++++++++++++++++++++++++
> 2 files changed, 37 insertions(+)
>
>
> diff --git a/fs/xfs/libxfs/xfs_shared.h b/fs/xfs/libxfs/xfs_shared.h
> index c6f4eb4..67ccb1a 100644
> --- a/fs/xfs/libxfs/xfs_shared.h
> +++ b/fs/xfs/libxfs/xfs_shared.h
> @@ -143,5 +143,6 @@ bool xfs_symlink_hdr_ok(xfs_ino_t ino, uint32_t offset,
> uint32_t size, struct xfs_buf *bp);
> void xfs_symlink_local_to_remote(struct xfs_trans *tp, struct xfs_buf *bp,
> struct xfs_inode *ip, struct xfs_ifork *ifp);
> +xfs_failaddr_t xfs_symlink_shortform_verify(struct xfs_inode *ip);
>
> #endif /* __XFS_SHARED_H__ */
> diff --git a/fs/xfs/libxfs/xfs_symlink_remote.c b/fs/xfs/libxfs/xfs_symlink_remote.c
> index b6ef6cb..5d9642e 100644
> --- a/fs/xfs/libxfs/xfs_symlink_remote.c
> +++ b/fs/xfs/libxfs/xfs_symlink_remote.c
> @@ -210,3 +210,39 @@ xfs_symlink_local_to_remote(
> xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsymlink_hdr) +
> ifp->if_bytes - 1);
> }
> +
> +/* Verify the consistency of an inline symlink. */
> +xfs_failaddr_t
> +xfs_symlink_shortform_verify(
> + struct xfs_inode *ip)
> +{
> + char *sfp;
> + char *endp;
> + struct xfs_ifork *ifp;
> + int size;
> +
> + ASSERT(ip->i_d.di_format == XFS_DINODE_FMT_LOCAL);
> + ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
> + sfp = (char *)ifp->if_u1.if_data;
> + size = ifp->if_bytes;
> + endp = sfp + size;
> +
> + /* Zero length symlinks can exist while we're deleting a remote one. */
> + if (size == 0)
> + return NULL;
> +
> + /* No negative sizes or overly long symlink targets. */
> + if (size < 0 || size > XFS_SYMLINK_MAXLEN)
> + return __this_address;
> +
> + /* No NULLs in the target either. */
> + for (; sfp < endp; sfp++) {
> + if (*sfp == 0)
> + return __this_address;
> + }
if (memchr(sfp, 0, size - 1))
return __this_address;
Otherwise looks ok.
Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
--
Dave Chinner
david@xxxxxxxxxxxxx
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