Messages in this thread | | | Date | Thu, 13 Nov 2008 09:45:12 +0100 | From | Mikael Pettersson <> | Subject | Re: [PATCH 2/2] x86: ia32_signal: remove unnecessary padding |
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H. Peter Anvin writes: > Hiroshi Shimamoto wrote: > > H. Peter Anvin wrote: > >> Mikael Pettersson wrote: > >>> It does cause each signal delivery to leak 2 uninitialised > >>> kernel bytes to the end of retcode[], which seems unnecessary. > >> Not just unnecessary, it is a huge no-no for security. > > > > Am I missing important thing? > > The frame->retcode is 8 bytes and packed structure with padding > > is 10 bytes each, and the code is copied to user stack 8 bytes only. > > > > err |= __copy_to_user(frame->retcode, &code, 8); > > > > I don't think the behavior is changed. > > > > Ah, nevermind, then. Then it fine, obviously.
Agreed. I wonder how on earth those templates ended up as 10 bytes large when retcode[] always has been 8 bytes.
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