Messages in this thread | | | Date | Thu, 7 Aug 2008 11:15:39 +0100 | From | Alan Cox <> | Subject | Re: [PATCH] x86: prevent binaries from making system calls using the wrong syscall interface |
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> Currently there is nothing to prevent 64 bit binaries from > attempting to make system calls using the 32 bit system call > interfaces and vice versa.
What about applications that choose to do this - Test tools - Tools where certain interfaces are only available 32bit ?
> Since the 32 bit and 64 bit system call numbers are different > this means that a binary could attempt to obfuscate which system > calls it was actually making by using the "wrong" system call > interface. In particular, the call to audit_syscall_entry() > relies on checking the TIF_IA32 flag to determine whether it is > dealing with a 32 or 64 bit system call without regard to the > actual type of system call that was made.While this specific issue > could be addressed by checking the TS_COMPAT flag in threadinfo_status > it seems preferable to simply disallow this situation altogether.
That is a significant change of kernel ABI considering it exists just to wallpaper over crappy audit tools.
I'm definitely against that approach.
Alan
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