[v21,02/30] splice: Make filemap_splice_read() check s_maxbytes

Message ID 20230520000049.2226926-3-dhowells@redhat.com
State New
Headers
Series splice: Kill ITER_PIPE |

Commit Message

David Howells May 20, 2023, midnight UTC
  Make filemap_splice_read() check s_maxbytes analogously to filemap_read().

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Steve French <stfrench@microsoft.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: David Hildenbrand <david@redhat.com>
cc: John Hubbard <jhubbard@nvidia.com>
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
---
 mm/filemap.c | 3 +++
 1 file changed, 3 insertions(+)
  

Comments

Christoph Hellwig May 20, 2023, 4:09 a.m. UTC | #1
Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
  
Christian Brauner May 20, 2023, 9:21 a.m. UTC | #2
On Sat, May 20, 2023 at 01:00:21AM +0100, David Howells wrote:
> Make filemap_splice_read() check s_maxbytes analogously to filemap_read().
> 
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: Christoph Hellwig <hch@lst.de>
> cc: Steve French <stfrench@microsoft.com>
> cc: Jens Axboe <axboe@kernel.dk>
> cc: Al Viro <viro@zeniv.linux.org.uk>
> cc: David Hildenbrand <david@redhat.com>
> cc: John Hubbard <jhubbard@nvidia.com>
> cc: linux-mm@kvack.org
> cc: linux-block@vger.kernel.org
> cc: linux-fsdevel@vger.kernel.org
> ---
>  mm/filemap.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/mm/filemap.c b/mm/filemap.c
> index a2006936a6ae..0fcb0b80c2e2 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -2887,6 +2887,9 @@ ssize_t filemap_splice_read(struct file *in, loff_t *ppos,
>  	bool writably_mapped;
>  	int i, error = 0;
>  
> +	if (unlikely(*ppos >= in->f_mapping->host->i_sb->s_maxbytes))

Pointer deref galore
Reviewed-by: Christian Brauner <brauner@kernel.org>
  

Patch

diff --git a/mm/filemap.c b/mm/filemap.c
index a2006936a6ae..0fcb0b80c2e2 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2887,6 +2887,9 @@  ssize_t filemap_splice_read(struct file *in, loff_t *ppos,
 	bool writably_mapped;
 	int i, error = 0;
 
+	if (unlikely(*ppos >= in->f_mapping->host->i_sb->s_maxbytes))
+		return 0;
+
 	init_sync_kiocb(&iocb, in);
 	iocb.ki_pos = *ppos;