Re: [PATCH] proc: fix type confusion in pde_set_flags()

[wangzijie <wangzijie1@honor.com>]

> On Thu, 4 Sep 2025 21:57:15 +0800 wangzijie <wangzijie1@honor.com> wrote:
> 
> > Commit 2ce3d282bd50 ("proc: fix missing pde_set_flags() for net proc files")
> > missed a key part in the definition of proc_dir_entry:
> > 
> > union {
> > 	const struct proc_ops *proc_ops;
> > 	const struct file_operations *proc_dir_ops;
> > };
> > 
> > So dereference of ->proc_ops assumes it is a proc_ops structure results in
> > type confusion and make NULL check for 'proc_ops' not work for proc dir.
> > 
> > Add !S_ISDIR(dp->mode) test before calling pde_set_flags() to fix it.
> > 
> > Fixes: 2ce3d282bd50 ("proc: fix missing pde_set_flags() for net proc files")
> 
> 2ce3d282bd50 had cc:stable, so I added cc:stable to this patch.
> 
> > Reported-by: Brad Spengler <spender@grsecurity.net>
> > Signed-off-by: wangzijie <wangzijie1@honor.com>
> 
> A link to Brad's report would be helpful please, if available.  We
> typically use Closes: for such things.

Closes: https://lore.kernel.org/all/20250903065758.3678537-1-wangzijie1@honor.com/

Thanks for reminder, I'm not sure if this link is appropriate.