Messages in this thread | | | From | Linus Torvalds <> | Date | Wed, 13 May 2020 12:51:59 -0700 | Subject | Re: [PATCH 3/5] exec: Remove recursion from search_binary_handler |
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On Tue, May 12, 2020 at 7:32 PM Rob Landley <rob@landley.net> wrote: > > On 5/12/20 7:20 PM, Linus Torvalds wrote: > > Ack. I think the AT_EXECFD thing is a sign that this isn't internal to > > binfmt_misc, but it also shouldn't be gating this issue. In reality, > > ELF is the only real binary format that matters - the script/misc > > binfmts are just indirection entries - and it supports AT_EXECFD, so > > let's just ignore the theoretical case of "maybe nobody exposes it". > > Would this potentially make the re-exec-yourself case easier to do at some > point? (Which nommu needs to do, and /proc/self/exe isn't always available.)
AT_EXECFD may be an ELF thing, but normal ELF binaries don't do that "we have a fd". So it only triggers for binfmt_misc (and only when the flag is set for "I want the fd").
So no, this wouldn't help re-exec-yourself in general.
Although I guess we could add an ELF section note that does that whole "executable fd" thing for other things too.
Everything is possible in theory..
Linus
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