linux-kernel - Re: [PATCH] proc: fix return value of proc_reg

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 2 Sep 2008 16:26:24 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Alexey Dobriyan <adobriyan@...il.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] proc: fix return value of proc_reg_open() in "too late"
 case

On Sat, 30 Aug 2008 09:34:12 +0400
Alexey Dobriyan <adobriyan@...il.com> wrote:

> If ->open() wasn't called, returning 0 is misleading and, theoretically,
> oopsable:
> 1. remove_proc_entry clears ->proc_fops, drops lock,
> 2. ->open "succeeds",
> 3. ->release oopses, because it assumes ->open was called (single_release()).
> 
> Signed-off-by: Alexey Dobriyan <adobriyan@...il.com>
> ---
> 
>  fs/proc/inode.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/fs/proc/inode.c
> +++ b/fs/proc/inode.c
> @@ -350,7 +350,7 @@ static int proc_reg_open(struct inode *inode, struct file *file)
>  	if (!pde->proc_fops) {
>  		spin_unlock(&pde->pde_unload_lock);
>  		kfree(pdeo);
> -		return rv;
> +		return -EINVAL;
>  	}
>  	pde->pde_users++;
>  	open = pde->proc_fops->open;

Can this code path ever actually be executed?  afacit if ->proc_fops is
ever NULL, the caller (proc_get_inode) would have already oopsed:

#ifdef CONFIG_COMPAT
				if (!de->proc_fops->compat_ioctl)
					inode->i_fop =
						&proc_reg_file_ops_no_compat;
				else
#endif
					inode->i_fop = &proc_reg_file_ops;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/