CSS/Harvard 2.9BSD bug report #13

[Keith Bostic]

Subject: Executable shell scripts can crash the system.

Index:	sys/sys1.c 2.9BSD

Description:
	Kernel doesn't check for more than one level of executable
	shell scripts.
Repeat-By:
	Execute "see" or any shell program that executes another shell
	script.
Fix:
	Apply the following diff.

sys1.c.right <<  >>  sys1.c.wrong
75,76c76,77
< 		goto bad;	/* check if script.  one level only */
< 	if (!indir && u.u_exdata.ux_shell[0] == '#' && u.u_exdata.ux_shell[1] == '!') {
---
> 		goto bad;	 /* check if script.  one level only */
> 	if (u.u_exdata.ux_shell[0] == '#' && u.u_exdata.ux_shell[1] == '!') {