On Thu, Dec 07, 2017 at 11:23:26PM +0000, Al Viro wrote:
> On Fri, Dec 08, 2017 at 12:03:07AM +0100, Vasyl Gomonovych wrote:
> > p could be NULL and passing into PTR_ERR
> >
> > Signed-off-by: Vasyl Gomonovych <gomonovych@xxxxxxxxx>
> > ---
> > fs/seq_file.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/fs/seq_file.c b/fs/seq_file.c
> > index 4be761c..8b700b9 100644
> > --- a/fs/seq_file.c
> > +++ b/fs/seq_file.c
> > @@ -262,8 +262,8 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
> > size_t offs = m->count;
> > loff_t next = pos;
> > p = m->op->next(m, p, &next);
> > - if (!p || IS_ERR(p)) {
> > - err = PTR_ERR(p);
> > + if (IS_ERR(p)) {
> > + err = (!p ? -EFAULT : PTR_ERR(p));
>
> What does it fix, if I might ask? And while we are at it, would
> you mind explaining the reasoning behind that change? Or, say,
> testing done to it...
While we are at it, where has that -EFAULT come from? And how
would it be ever reached, seeing that IS_ERR(NULL) is false?
