This is a note to let you know that I've just added the patch titled

kernfs: fix regression in kernfs_fop_write caused by wrong type

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: kernfs-fix-regression-in-kernfs_fop_write-caused-by-wrong-type.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From ba87977a49913129962af8ac35b0e13e0fa4382d Mon Sep 17 00:00:00 2001

From: Ivan Vecera ivecera@redhat.com Date: Fri, 19 Jan 2018 09:18:54 +0100 Subject: kernfs: fix regression in kernfs_fop_write caused by wrong type

From: Ivan Vecera ivecera@redhat.com

commit ba87977a49913129962af8ac35b0e13e0fa4382d upstream.

Commit b7ce40cff0b9 ("kernfs: cache atomic_write_len in kernfs_open_file") changes type of local variable 'len' from ssize_t to size_t. This change caused that the *ppos value is updated also when the previous write callback failed.

Mentioned snippet: ... len = ops->write(...); <- return value can be negative ... if (len > 0) <- true here in this case *ppos += len; ...

Fixes: b7ce40cff0b9 ("kernfs: cache atomic_write_len in kernfs_open_file") Acked-by: Tejun Heo tj@kernel.org Signed-off-by: Ivan Vecera ivecera@redhat.com Signed-off-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- fs/kernfs/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -275,7 +275,7 @@ static ssize_t kernfs_fop_write(struct f { struct kernfs_open_file *of = kernfs_of(file); const struct kernfs_ops *ops; - size_t len; + ssize_t len; char *buf;

if (of->atomic_write_len) {

Patches currently in stable-queue which might be from ivecera@redhat.com are

queue-4.9/kernfs-fix-regression-in-kernfs_fop_write-caused-by-wrong-type.patch