Re: [PATCH] exec: do not leave bprm->interp on stack

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



+-- On Mon, 19 Nov 2012, Kees Cook wrote --+
| I think to avoid the explosion of request_module calls in the abusive
| case, we could simply return ELOOP instead of ENOEXEC on max
| recursion.

 -> http://www.spinics.net/lists/mm-commits/msg92433.html

1. returning -ELOOP has a side effect of not reaching to request_module()
   ever, for:
==
#ifdef CONFIG_MODULES
1415                 if (retval != -ENOEXEC || bprm->mm == NULL) {
1416                         break;
1417                 } else {
			...
==

2. above patch does not seem to fix the 2^6(64) recursions issue, for:
==
+			bprm->recursion_depth = depth + 1;
 			retval = fn(bprm);
 			bprm->recursion_depth = depth;
==

setting - recursion_dept = depth - again and the outer for(try=0;try<2...) 
loop seems to be causing the 2^6 recursions.

Thank you. 
--
Prasad J Pandit / Red Hat Security Response Team
DB7A 84C5 D3F9 7CD1 B5EB  C939 D048 7860 3655 602B
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux