Re: two 2.5 modules bugs

[Petr Vandrovec <vandrove@vc.cvut.cz>]

On Fri, Dec 27, 2002 at 05:16:35PM +0100, Mikael Pettersson wrote:
> 1. With kernel 2.5.53 and module-init-tools-0.9.6, "modprobe tulip"
>    fails and goes into an infinite CPU-consuming loop. The problem
>    appears to be related to the dependency from tulip to crc32. If I
>    manually modprobe crc32 before modprobe tulip, it works. If crc32
>    isn't loaded, modprobe tulip first loads crc32 and then loops.
> 
>    module-init-tools-0.9.5 did not have this problem.

Load modprobe with MALLOC_CHECK_=1. It will reveal that it tries to
free() some non-mallocated area. 

Try patch below, insmod() can realloc/free its second argument, so
we can doublefree it, and glibc's malloc goes wild. It fixes problems
I had with modprobe ipx (which depends on psnap/p8022 which depends
on llc).
 
--- 0.9.6-1/modprobe.c.dist	2002-12-26 10:32:22.000000000 +0100
+++ 0.9.6-1/modprobe.c	2002-12-28 00:12:16.000000000 +0100
@@ -582,7 +582,7 @@
 		char *baseopts = NOFAIL(strdup(""));
 		insmod(list, baseopts, NULL, 0, dry_run, verbose, options,
 		       commands, 0);
-		free(baseopts);
+//		free(baseopts);
 	}
 
 	/* Did config file override command or add options? */

							Petr Vandrovec
							vandrove@vc.cvut.cz