Messages in this thread | | | Subject | Re: [PATCH, local root on 2.4, 2.6?] compute_creds race | From | Olaf Dietsche <> | Date | Sat, 10 Apr 2004 20:41:29 +0200 |
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Andy Lutomirski <luto@stanford.edu> writes:
> Olaf Dietsche wrote: > >> Andy Lutomirski <luto@myrealbox.com> writes: >> >>>The setuid program is now running with uid=euid=500 but full permitted >>>capabilities. There are two (or three) ways to effectively get local >>>root now: >> What about this slightly shorter fix? >> diff -urN a/fs/exec.c b/fs/exec.c >> --- a/fs/exec.c Fri Mar 12 01:19:06 2004 >> +++ b/fs/exec.c Sat Apr 10 10:54:20 2004 >> @@ -942,6 +942,9 @@ >> if(!capable(CAP_SETUID)) { >> bprm->e_uid = current->uid; >> bprm->e_gid = current->gid; >> + cap_clear (bprm->cap_inheritable); >> + cap_clear (bprm->cap_permitted); >> + cap_clear (bprm->cap_effective); >> } >> } >> } > > This makes the bprm_compute_creds hook even less sane than now > (i.e. it assumes that all LSMs will work like the current capability > modules). The hook should allow LSM to change this functionality > without reintroducing the race. For example, it breaks my work on > fixing capabilities.
This patch fixes the problem without moving and renaming huge amounts of code. And the hook is still in place, so I don't see your problems.
If you look at the code - as seen in 2.4 and early 2.5 - that's (more or less) the place where the fix should be.
Anyway, I don't really object against moving code around.
Regards, Olaf. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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