Messages in this thread | | | Subject | Re: [PATCH] exec: do not leave bprm->interp on stack | From | Tetsuo Handa <> | Date | Thu, 25 Oct 2012 21:03:14 +0900 |
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P J P wrote: > > Hello Kees, > > +-- On Wed, 24 Oct 2012, Kees Cook wrote --+ > | What should the code here _actually_ be doing? The _script and _misc > | handlers expect to rewrite the bprm contents and recurse, but the module > | loader want to try again. It's not clear to me what the binfmt module > | handler is even there for; I don't see any binfmt-XXXX aliases in the tree. > | If nothing uses it, should we just rip it out? That would solve it too. > > I've been following this issue and updated versions of HDs patch. Below is a > small patch to search_binary_handler() routine, which attempts to make the > request_module call before calling load_script routine. > > Besides fixing the stack disclosure issue it also helps to *simplify* the > search_binary_handler routine by removing the -for (try=0;try<2;try++)- loop. > > I'd really appreciate any comments/suggestions you may have.
Excuse me, but why do you change definition of printable(c) ? Looks like a regression.
Wouldn't your patch trigger call request_module() whenever a script starting with "#!/bin/sh" is executed?
And if you meant
if (!(printable(bprm->buf[0]) && printable(bprm->buf[1]) && printable(bprm->buf[2]) && printable(bprm->buf[3])))
then, wouldn't that trigger request_module() recursion?
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