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Re: [Qemu-devel] qemu allows code execution on the stack, even if the qu
Re: [Qemu-devel] qemu allows code execution on the stack, even if the quest operating system makes the stack nonexecutable
Tue, 12 Oct 2004 19:58:32 +0200
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.2) Gecko/20040803
If CS.limit is used to implement non executable memory, it is normal
because QEMU does not test segment limits for performance reasons.
QEMU will someday implement PAE and NX bits - it is the most efficient
way to handle this.
joro 42 wrote:
tested openwall linux and openbsd 3.5 under qemu.
both of them claim to make the stack non executable when on real x86.
but under qemu, code on the stack seems executed on owl and obsd3.5.
try the following program:
char trap="\xcc"; // "\xeb\xfe" for loop
it executes code instead of SEGV on openwall/openbsd.