oss-sec mailing list archives
Re: [PATCH] implement privmode support in dash
From: jca+dash () wxcvbn org (Jérémie Courrèges-Anglas)
Date: Fri, 23 Aug 2013 13:40:31 +0200
Also, Tavis Ormandy <taviso () google com> writes: [...]
Apart from that, it is better to check the return value from setuid() and similar functions. In particular, some versions of Linux may fail setuid() for [EAGAIN], leaving the process running with the same privileges.I don't think this is true anymore, but I have no strong objection to adding it, so long as it's noted that bash and pdksh do not do this.
Just for reference, from mksh: [...] #ifdef SETUID_CAN_FAIL_WITH_EAGAIN /* we don't need to check for other codes, EPERM won't happen */ #define DO_SETUID(func, argvec) do { \ if ((func argvec) && errno == EAGAIN) \ errorf("%s failed with EAGAIN, probably due to a" \ " too low process limit; aborting", #func); \ } while (/* CONSTCOND */ 0) #else #define DO_SETUID(func, argvec) func argvec #endif [...] if (f == FPRIVILEGED && oldval && !newval) { /* Turning off -p? */ /*XXX this can probably be optimised */ kshegid = kshgid = getgid(); #if HAVE_SETRESUGID DO_SETUID(setresgid, (kshegid, kshegid, kshegid)); #if HAVE_SETGROUPS /* setgroups doesn't EAGAIN on Linux */ setgroups(1, &kshegid); #endif DO_SETUID(setresuid, (ksheuid, ksheuid, ksheuid)); #else /* seteuid, setegid, setgid don't EAGAIN on Linux */ ksheuid = kshuid = getuid(); #ifndef MKSH__NO_SETEUGID seteuid(ksheuid); #endif DO_SETUID(setuid, (ksheuid)); #ifndef MKSH__NO_SETEUGID setegid(kshegid); #endif setgid(kshegid); #endif } [...]
Tavis.
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Current thread:
- [PATCH] implement privmode support in dash Tavis Ormandy (Aug 22)
- Re: [PATCH] implement privmode support in dash Simon McVittie (Aug 22)
- Re: [PATCH] implement privmode support in dash Tavis Ormandy (Aug 23)
- Re: [PATCH] implement privmode support in dash Ludwig Nussel (Aug 23)
- Re: [PATCH] implement privmode support in dash Harald van Dijk (Aug 22)
- Re: [PATCH] implement privmode support in dash Tavis Ormandy (Aug 22)
- Re: [PATCH] implement privmode support in dash Jilles Tjoelker (Aug 22)
- Re: [PATCH] implement privmode support in dash Tavis Ormandy (Aug 22)
- Re: [PATCH] implement privmode support in dash Jérémie Courrèges-Anglas (Aug 23)
- Re: [PATCH] implement privmode support in dash Jérémie Courrèges-Anglas (Aug 23)
- Re: [PATCH] implement privmode support in dash Roy (Aug 23)
- Re: [PATCH] implement privmode support in dash Simon McVittie (Aug 22)
- Re: [PATCH] implement privmode support in dash Seth Arnold (Aug 22)
- Re: [PATCH] implement privmode support in dash Michael Samuel (Aug 22)
- Re: [PATCH] implement privmode support in dash Tavis Ormandy (Aug 23)
- Re: [PATCH] implement privmode support in dash Florian Weimer (Aug 23)