Linux-kernel mailing list archive 1998-31,: Re: [PATCH] [SECURITY] suid procs exec'd with bad 0,1,2 fds

# Re: [PATCH] [SECURITY] suid procs exec'd with bad 0,1,2 fds

Perry Harrington (pedward@sun4.apsoft.com)
Tue, 4 Aug 1998 13:32:08 -0700 (PDT)

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> Also true.
>
> But I have yet another technical argument. It BREAKS the existing elf
> ABI's of all systems I know of.
>
> I have the 32-bit Sparc and 32-bit MIPS ELF specifications here for
> reference and both specify:
>
> "The stack segment has READ, WRITE, and EXECUTE permissions."
>

But what uses exec stacks, other than exploits?

I know that breaking certain specs is bad, but what if the perceived value
is worth more than full adherence to the spec?

> I don't have it handy, but I would not be surprised if the x86 ELF
> specs say the same thing. Someone can easily check this.
>
> Dean Gaudet made a reference to Solaris2.7 and the fact that they've
> turned off execute permission for the stack on Sparc. This is for
> 64-bit Sparc binaries covered on the new 64-bit V9 processor ABI.
> They did not turn off execution for the stack segment when existing
> 32-bit binaries run.
>
> Later,
> David S. Miller
> davem@dm.cobaltmicro.com

    --
    Perry Harrington       Linux rules all OSes.    APSoft      ()
    email: perry@apsoft.com 			Think Blue. /\

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- Next message: Andi Kleen: "Re: ftp trouble 2.1.114 <> Cray-System"
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- Reply: Stephen Frost: "Re: [PATCH] [SECURITY] suid procs exec'd with bad 0,1,2 fds"