Messages in this thread | | | Date | Wed, 05 Nov 2003 23:09:24 -0500 | From | Scott Robert Ladd <> | Subject | Re: BK2CVS problem |
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Larry McVoy wrote: > On Wed, Nov 05, 2003 at 04:48:09PM -0600, Chad Kitching wrote: > >>From: Zwane Mwaikambo >> >>>>+ if ((options == (__WCLONE|__WALL)) && (current->uid = 0)) >>>>+ retval = -EINVAL; >>> >>>That looks odd >>> >> >>Setting current->uid to zero when options __WCLONE and __WALL are set? The >>retval is dead code because of the next line, but it looks like an attempt >>to backdoor the kernel, does it not? > > > It sure does. Note "current->uid = 0", not "current->uid == 0". > Good eyes, I missed that. This function is sys_wait4() so by passing in > __WCLONE|__WALL you are root. How nice.
In other words, the theoretical exploit was inserted by someone clever. Do we have any idea who?
BTW, good job catching the problem Larry.
-- Scott Robert Ladd Coyote Gulch Productions (http://www.coyotegulch.com) Software Invention for High-Performance Computing
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