2021-05-04 12:45:31

by Khaled Romdhani

Subject: [PATCH-next] fs/cifs: Fix resource leak

The -EIO error return path is leaking memory allocated
to page. Fix this by invoking the free_dentry_path before
the return.

Addresses-Coverity: ("Resource leak")
Signed-off-by: Khaled ROMDHANI <[email protected]>
---
fs/cifs/link.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 1cbe7ec73728..1485c6095ba1 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -686,8 +686,10 @@ cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
void *page = alloc_dentry_path();
struct inode *newinode = NULL;

- if (unlikely(cifs_forced_shutdown(cifs_sb)))
+ if (unlikely(cifs_forced_shutdown(cifs_sb))) {
+ free_dentry_path(page);
return -EIO;
+ }

xid = get_xid();

--
2.17.1

2021-05-04 13:49:44

by Dan Carpenter

Subject: Re: [PATCH-next] fs/cifs: Fix resource leak

On Tue, May 04, 2021 at 01:43:43PM +0100, Khaled ROMDHANI wrote:
> The -EIO error return path is leaking memory allocated
> to page. Fix this by invoking the free_dentry_path before
> the return.
>
> Addresses-Coverity: ("Resource leak")
> Signed-off-by: Khaled ROMDHANI <[email protected]>

Add a Fixes tag.

Fixes: 583248493f78 ("cifs: add shutdown support")

> ---
> fs/cifs/link.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/fs/cifs/link.c b/fs/cifs/link.c
> index 1cbe7ec73728..1485c6095ba1 100644
> --- a/fs/cifs/link.c
> +++ b/fs/cifs/link.c
> @@ -686,8 +686,10 @@ cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
> void *page = alloc_dentry_path();
> struct inode *newinode = NULL;
>
> - if (unlikely(cifs_forced_shutdown(cifs_sb)))
> + if (unlikely(cifs_forced_shutdown(cifs_sb))) {
> + free_dentry_path(page);
> return -EIO;
> + }

Better to move the allocation here. Avoid calling functions which can
fail in the declaration block. Better to test for NULL directly instead
of hiding the test inside the build_path_from_dentry() function.

page = alloc_dentry_path();
if (!page)
return -ENOMEM;

The error handling in this function is slightly unweildy...

regards,
dan carpenter

2021-05-04 15:04:44

by Khaled Romdhani

Subject: Re: [PATCH-next] fs/cifs: Fix resource leak

On Tue, May 04, 2021 at 04:44:45PM +0300, Dan Carpenter wrote:
> On Tue, May 04, 2021 at 01:43:43PM +0100, Khaled ROMDHANI wrote:
> > The -EIO error return path is leaking memory allocated
> > to page. Fix this by invoking the free_dentry_path before
> > the return.
> >
> > Addresses-Coverity: ("Resource leak")
> > Signed-off-by: Khaled ROMDHANI <[email protected]>
>
> Add a Fixes tag.
>
> Fixes: 583248493f78 ("cifs: add shutdown support")
>

Yes, I will add a Fixes tag.

> > ---
> > fs/cifs/link.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/cifs/link.c b/fs/cifs/link.c
> > index 1cbe7ec73728..1485c6095ba1 100644
> > --- a/fs/cifs/link.c
> > +++ b/fs/cifs/link.c
> > @@ -686,8 +686,10 @@ cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
> > void *page = alloc_dentry_path();
> > struct inode *newinode = NULL;
> >
> > - if (unlikely(cifs_forced_shutdown(cifs_sb)))
> > + if (unlikely(cifs_forced_shutdown(cifs_sb))) {
> > + free_dentry_path(page);
> > return -EIO;
> > + }
>
> Better to move the allocation here. Avoid calling functions which can
> fail in the declaration block. Better to test for NULL directly instead
> of hiding the test inside the build_path_from_dentry() function.
>
> page = alloc_dentry_path();
> if (!page)
> return -ENOMEM;
>
> The error handling in this function is slightly unweildy...
>
> regards,
> dan carpenter
>

Yes, it would be better to move the allocation...
I will send a V2.

Thanks.