Date: Thu, 21 Aug 2014 16:33:14 +1000 From: Murray McAllister <mmcallis@...hat.com> To: oss-security@...ts.openwall.com Subject: Re: CVE request: possible overflow in vararg functions Additionally, Fedora has 5.2.2, but it does not have the fix, so even if shipping 5.2.2 it may be worth checking... On 08/21/2014 04:31 PM, Murray McAllister wrote: > Good morning, > > An overflow was reported to have been fixed in Lua 5.2.2. A reproducer > and patch are available from: > > http://www.lua.org/bugs.html#5.2.2-1 > > The reproducer affects older versions too (such as 5.1.4). One way an > attacker could trigger this issue is if they can control parameters to a > loadstring call (an eval in Lua, http://en.wikipedia.org/wiki/Eval#Lua). > > Could a CVE please be assigned if one has not been already? > > Some notes: > > valgrind shows this crashes with invalid writes, but I am not sure if > this is really a stack or heap overflow but something else. In > luaD_precall(): > > 330 for (; n < p->numparams; n++) > 331 setnilvalue(L->top++); /* complete missing arguments */ > > This goes through 49 times with the reproducer (?possibly lifting what > Lua thinks is the stack into the heap area?). > > After that finishes: > > 333 ci = next_ci(L); > > Results in a call to luaE_extendCI(), where the issue is triggered while > attempting to call luaM_new() (I did not get further than this yet). > > Thanks, > > -- > Murray McAllister / Red Hat Product Security > > https://bugzilla.redhat.com/show_bug.cgi?id=1132304
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