Re: [gentoo-portage-dev] [PATCH] ebuild.sh: Completely ban external commands in global scope
> On Fri, 8 Sep 2017, Robin H Johnson wrote: > On Thu, Aug 31, 2017 at 10:45:42PM +0200, Michał Górny wrote: >> +export PATH=/dev/null > Minor nitpick: The Single UNIX spec says that PATH is a set of > prefixes, and that they're treated as directories. > http://pubs.opengroup.org/onlinepubs/7908799/xbd/envvar.html > I think it might be good to use either a non-existing path, or a > known empty directory (/var/empty), rather than /dev/null which DOES > exist. Is /var/empty standard? On my system here, it belongs to net-misc/openssh. Also any /dev/null/foo is guaranteed not to exist, so I don't see how pathname resolution could possibly succeed when PATH is /dev/null. Ulrich pgpVY9QRev455.pgp Description: PGP signature
Re: [gentoo-portage-dev] [PATCH] ebuild.sh: Completely ban external commands in global scope
On Thu, Aug 31, 2017 at 10:45:42PM +0200, Michał Górny wrote: > + export PATH=/dev/null Minor nitpick: The Single UNIX spec says that PATH is a set of prefixes, and that they're treated as directories. http://pubs.opengroup.org/onlinepubs/7908799/xbd/envvar.html I think it might be good to use either a non-existing path, or a known empty directory (/var/empty), rather than /dev/null which DOES exist. -- Robin Hugh Johnson Gentoo Linux: Dev, Infra Lead, Foundation Asst. Treasurer E-Mail : robb...@gentoo.org GnuPG FP : 11ACBA4F 4778E3F6 E4EDF38E B27B944E 34884E85 GnuPG FP : 7D0B3CEB E9B85B1F 825BCECF EE05E6F6 A48F6136 signature.asc Description: Digital signature
Re: [gentoo-portage-dev] [PATCH] ebuild.sh: Completely ban external commands in global scope
Must be old age setting in :( Thanks, -A On Fri, Sep 8, 2017 at 2:54 PM, Michał Górnywrote: > W dniu pią, 08.09.2017 o godzinie 14∶48 -0400, użytkownik Alec Warner > napisał: > > Why PATH=/dev/null vs export PATH="" > > + # note: we can't use empty because it implies current directory > > > > > On Thu, Sep 7, 2017 at 3:36 AM, Michał Górny wrote: > > > > > Dnia 31 sierpnia 2017 22:45:42 CEST, "Michał Górny" > > > > napisał(a): > > > > Set PATH to /dev/null when sourcing the ebuild for dependency > > > > resolution > > > > in order to prevent shell from finding external commands via PATH > > > > lookup. While this does not prevent executing programs via full path, > > > > it > > > > should catch the majority of accidental uses. > > > > > > > > Closes: https://github.com/gentoo/portage/pull/199 > > > > > > > > // Note: this can't be merged right now since we still have ebuilds > > > > // calling external commands; see: > > > > // https://bugs.gentoo.org/show_bug.cgi?id=629222 > > > > > > Update: gentoo is green now > > > > > > > --- > > > > bin/ebuild.sh | 6 +- > > > > bin/isolated-functions.sh | 4 > > > > 2 files changed, 9 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/bin/ebuild.sh b/bin/ebuild.sh > > > > index c23561651..94a44d534 100755 > > > > --- a/bin/ebuild.sh > > > > +++ b/bin/ebuild.sh > > > > @@ -80,8 +80,12 @@ else > > > > done > > > > unset funcs x > > > > > > > > + # prevent the shell from finding external executables > > > > + # note: we can't use empty because it implies current > directory > > > > + _PORTAGE_ORIG_PATH=${PATH} > > > > + export PATH=/dev/null > > > > command_not_found_handle() { > > > > - die "Command not found while sourcing ebuild: ${*}" > > > > + die "External commands disallowed while sourcing > ebuild: > > > > > > ${*}" > > > > } > > > > fi > > > > > > > > diff --git a/bin/isolated-functions.sh b/bin/isolated-functions.sh > > > > index e320f7132..b28e44f18 100644 > > > > --- a/bin/isolated-functions.sh > > > > +++ b/bin/isolated-functions.sh > > > > @@ -121,6 +121,10 @@ __helpers_die() { > > > > } > > > > > > > > die() { > > > > + # restore PATH since die calls basename & sed > > > > + # TODO: make it pure bash > > > > + [[ -n ${_PORTAGE_ORIG_PATH} ]] && PATH=${_PORTAGE_ORIG_PATH} > > > > + > > > > set +x # tracing only produces useless noise here > > > > local IFS=$' \t\n' > > > > > > > > > > > > > -- > > > Best regards, > > > Michał Górny (by phone) > > > > > > > > -- > Best regards, > Michał Górny > > >
Re: [gentoo-portage-dev] [PATCH] ebuild.sh: Completely ban external commands in global scope
W dniu pią, 08.09.2017 o godzinie 14∶48 -0400, użytkownik Alec Warner napisał: > Why PATH=/dev/null vs export PATH="" + # note: we can't use empty because it implies current directory > > On Thu, Sep 7, 2017 at 3:36 AM, Michał Górnywrote: > > > Dnia 31 sierpnia 2017 22:45:42 CEST, "Michał Górny" > > napisał(a): > > > Set PATH to /dev/null when sourcing the ebuild for dependency > > > resolution > > > in order to prevent shell from finding external commands via PATH > > > lookup. While this does not prevent executing programs via full path, > > > it > > > should catch the majority of accidental uses. > > > > > > Closes: https://github.com/gentoo/portage/pull/199 > > > > > > // Note: this can't be merged right now since we still have ebuilds > > > // calling external commands; see: > > > // https://bugs.gentoo.org/show_bug.cgi?id=629222 > > > > Update: gentoo is green now > > > > > --- > > > bin/ebuild.sh | 6 +- > > > bin/isolated-functions.sh | 4 > > > 2 files changed, 9 insertions(+), 1 deletion(-) > > > > > > diff --git a/bin/ebuild.sh b/bin/ebuild.sh > > > index c23561651..94a44d534 100755 > > > --- a/bin/ebuild.sh > > > +++ b/bin/ebuild.sh > > > @@ -80,8 +80,12 @@ else > > > done > > > unset funcs x > > > > > > + # prevent the shell from finding external executables > > > + # note: we can't use empty because it implies current directory > > > + _PORTAGE_ORIG_PATH=${PATH} > > > + export PATH=/dev/null > > > command_not_found_handle() { > > > - die "Command not found while sourcing ebuild: ${*}" > > > + die "External commands disallowed while sourcing ebuild: > > > > ${*}" > > > } > > > fi > > > > > > diff --git a/bin/isolated-functions.sh b/bin/isolated-functions.sh > > > index e320f7132..b28e44f18 100644 > > > --- a/bin/isolated-functions.sh > > > +++ b/bin/isolated-functions.sh > > > @@ -121,6 +121,10 @@ __helpers_die() { > > > } > > > > > > die() { > > > + # restore PATH since die calls basename & sed > > > + # TODO: make it pure bash > > > + [[ -n ${_PORTAGE_ORIG_PATH} ]] && PATH=${_PORTAGE_ORIG_PATH} > > > + > > > set +x # tracing only produces useless noise here > > > local IFS=$' \t\n' > > > > > > > > > -- > > Best regards, > > Michał Górny (by phone) > > > > -- Best regards, Michał Górny
Re: [gentoo-portage-dev] [PATCH] ebuild.sh: Completely ban external commands in global scope
Dnia 31 sierpnia 2017 22:45:42 CEST, "Michał Górny"napisał(a): >Set PATH to /dev/null when sourcing the ebuild for dependency >resolution >in order to prevent shell from finding external commands via PATH >lookup. While this does not prevent executing programs via full path, >it >should catch the majority of accidental uses. > >Closes: https://github.com/gentoo/portage/pull/199 > >// Note: this can't be merged right now since we still have ebuilds >// calling external commands; see: >// https://bugs.gentoo.org/show_bug.cgi?id=629222 Update: gentoo is green now >--- > bin/ebuild.sh | 6 +- > bin/isolated-functions.sh | 4 > 2 files changed, 9 insertions(+), 1 deletion(-) > >diff --git a/bin/ebuild.sh b/bin/ebuild.sh >index c23561651..94a44d534 100755 >--- a/bin/ebuild.sh >+++ b/bin/ebuild.sh >@@ -80,8 +80,12 @@ else > done > unset funcs x > >+ # prevent the shell from finding external executables >+ # note: we can't use empty because it implies current directory >+ _PORTAGE_ORIG_PATH=${PATH} >+ export PATH=/dev/null > command_not_found_handle() { >- die "Command not found while sourcing ebuild: ${*}" >+ die "External commands disallowed while sourcing ebuild: ${*}" > } > fi > >diff --git a/bin/isolated-functions.sh b/bin/isolated-functions.sh >index e320f7132..b28e44f18 100644 >--- a/bin/isolated-functions.sh >+++ b/bin/isolated-functions.sh >@@ -121,6 +121,10 @@ __helpers_die() { > } > > die() { >+ # restore PATH since die calls basename & sed >+ # TODO: make it pure bash >+ [[ -n ${_PORTAGE_ORIG_PATH} ]] && PATH=${_PORTAGE_ORIG_PATH} >+ > set +x # tracing only produces useless noise here > local IFS=$' \t\n' > -- Best regards, Michał Górny (by phone)
[gentoo-portage-dev] [PATCH] ebuild.sh: Completely ban external commands in global scope
Set PATH to /dev/null when sourcing the ebuild for dependency resolution in order to prevent shell from finding external commands via PATH lookup. While this does not prevent executing programs via full path, it should catch the majority of accidental uses. Closes: https://github.com/gentoo/portage/pull/199 // Note: this can't be merged right now since we still have ebuilds // calling external commands; see: // https://bugs.gentoo.org/show_bug.cgi?id=629222 --- bin/ebuild.sh | 6 +- bin/isolated-functions.sh | 4 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/bin/ebuild.sh b/bin/ebuild.sh index c23561651..94a44d534 100755 --- a/bin/ebuild.sh +++ b/bin/ebuild.sh @@ -80,8 +80,12 @@ else done unset funcs x + # prevent the shell from finding external executables + # note: we can't use empty because it implies current directory + _PORTAGE_ORIG_PATH=${PATH} + export PATH=/dev/null command_not_found_handle() { - die "Command not found while sourcing ebuild: ${*}" + die "External commands disallowed while sourcing ebuild: ${*}" } fi diff --git a/bin/isolated-functions.sh b/bin/isolated-functions.sh index e320f7132..b28e44f18 100644 --- a/bin/isolated-functions.sh +++ b/bin/isolated-functions.sh @@ -121,6 +121,10 @@ __helpers_die() { } die() { + # restore PATH since die calls basename & sed + # TODO: make it pure bash + [[ -n ${_PORTAGE_ORIG_PATH} ]] && PATH=${_PORTAGE_ORIG_PATH} + set +x # tracing only produces useless noise here local IFS=$' \t\n' -- 2.14.1