Re: [PATCH] proc_mknod() should check the mode parameter

[Erik Mouw]

On Wed, Apr 18, 2001 at 05:51:08PM -0400, Alexander Viro wrote:
> On Wed, 18 Apr 2001, Erik Mouw wrote:
> > While documenting the procfs interface (more of that later), I came
> > across proc_mknod() which is supposed to be used to create devices in
> > the procfs. IMHO it should therefore check if the mode parameter
> > contains S_IFBLK or S_IFCHR.
> 
> Why? All callers of proc_mknod() are in the kernel and they should
> know better. I could understand
> 	if (....)
> 		BUG();
> but silently doing nothing is really odd.

OK, what about this one:

Index: fs/proc/generic.c
===================================================================
RCS file: /home/erik/cvsroot/elinux/fs/proc/generic.c,v
retrieving revision 1.1.1.16
diff -u -r1.1.1.16 generic.c
--- fs/proc/generic.c	2001/04/08 23:34:42	1.1.1.16
+++ fs/proc/generic.c	2001/04/18 21:55:14
@@ -445,6 +445,9 @@
 	const char *fn = name;
 	int len;
 
+	if (! (S_ISCHR(mode) || S_ISBLK(mode)))
+		BUG();
+
 	if (!parent && xlate_proc_name(name, &parent, &fn) != 0)
 		goto out;
 	len = strlen(fn);

Erik

-- 
J.A.K. (Erik) Mouw, Information and Communication Theory Group, Department
of Electrical Engineering, Faculty of Information Technology and Systems,
Delft University of Technology, PO BOX 5031,  2600 GA Delft, The Netherlands
Phone: [phone]  Fax: [phone]  Email: [e-mail]
WWW: http://www-ict.its.tudelft.nl/~erik/