[PATCH] ceph: Fix an Oops in error handling

[PATCH] ceph: Fix an Oops in error handling

[Dan Carpenter]

The "req" pointer is an error pointer and not NULL so this check needs
to be fixed.

Fixes: 1cf7fdf52d5a ("ceph: convert readpage to fscache read helper")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 fs/ceph/addr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 5eec6f66fe52..fb0238a4d34f 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -273,7 +273,7 @@ static void ceph_netfs_issue_op(struct netfs_read_subrequest *subreq)
 	if (err)
 		iput(inode);
 out:
-	if (req)
+	if (!IS_ERR_OR_NULL(req))
 		ceph_osdc_put_request(req);
 	if (err)
 		netfs_subreq_terminated(subreq, err);
-- 
2.29.2

Re: [PATCH] ceph: Fix an Oops in error handling

[Ilya Dryomov]

On Tue, Feb 2, 2021 at 6:47 AM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> The "req" pointer is an error pointer and not NULL so this check needs
> to be fixed.
>
> Fixes: 1cf7fdf52d5a ("ceph: convert readpage to fscache read helper")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
>  fs/ceph/addr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
> index 5eec6f66fe52..fb0238a4d34f 100644
> --- a/fs/ceph/addr.c
> +++ b/fs/ceph/addr.c
> @@ -273,7 +273,7 @@ static void ceph_netfs_issue_op(struct netfs_read_subrequest *subreq)
>         if (err)
>                 iput(inode);
>  out:
> -       if (req)
> +       if (!IS_ERR_OR_NULL(req))
>                 ceph_osdc_put_request(req);
>         if (err)
>                 netfs_subreq_terminated(subreq, err);

Hi Dan,

I think a better fix would be to set req to NULL in the offending
IS_ERR branch since ceph_osdc_new_request() never returns NULL or
use two separate goto labels.

While at it, the initialization of req and the check on req before
calling ceph_osdc_put_request() are redundant.

Thanks,

                Ilya

Re: [PATCH] ceph: Fix an Oops in error handling

[Jeff Layton]

On Tue, 2021-02-02 at 08:47 +0300, Dan Carpenter wrote:
> The "req" pointer is an error pointer and not NULL so this check needs
> to be fixed.
> 
> Fixes: 1cf7fdf52d5a ("ceph: convert readpage to fscache read helper")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
>  fs/ceph/addr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
> index 5eec6f66fe52..fb0238a4d34f 100644
> --- a/fs/ceph/addr.c
> +++ b/fs/ceph/addr.c
> @@ -273,7 +273,7 @@ static void ceph_netfs_issue_op(struct netfs_read_subrequest *subreq)
>  	if (err)
>  		iput(inode);
>  out:
> -	if (req)
> +	if (!IS_ERR_OR_NULL(req))
>  		ceph_osdc_put_request(req);
>  	if (err)
>  		netfs_subreq_terminated(subreq, err);

Good catch.

David, could you take this into your fscache-next branch?

Reviewed-by: Jeff Layton <jlayton@kernel.org>

Re: [PATCH] ceph: Fix an Oops in error handling

[Dan Carpenter]

On Tue, Feb 02, 2021 at 07:37:57AM -0500, Jeff Layton wrote:
> On Tue, 2021-02-02 at 08:47 +0300, Dan Carpenter wrote:
> > The "req" pointer is an error pointer and not NULL so this check needs
> > to be fixed.
> > 
> > Fixes: 1cf7fdf52d5a ("ceph: convert readpage to fscache read helper")
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > ---
> >  fs/ceph/addr.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
> > index 5eec6f66fe52..fb0238a4d34f 100644
> > --- a/fs/ceph/addr.c
> > +++ b/fs/ceph/addr.c
> > @@ -273,7 +273,7 @@ static void ceph_netfs_issue_op(struct netfs_read_subrequest *subreq)
> >  	if (err)
> >  		iput(inode);
> >  out:
> > -	if (req)
> > +	if (!IS_ERR_OR_NULL(req))
> >  		ceph_osdc_put_request(req);
> >  	if (err)
> >  		netfs_subreq_terminated(subreq, err);
> 
> Good catch.
> 
> David, could you take this into your fscache-next branch?
> 
> Reviewed-by: Jeff Layton <jlayton@kernel.org>

Jeff sent a different fix for this.  Let's just apply his instead.

regards,
dan carpenter