Only set up FAKECHROOT_CMD_SUBST for paths in PATH containing the original binary

If FAKECHROOT_CMD_SUBST sets up wrong substitutions, then binaries
cannot be found. For example if /usr/bin/chroot is listed in
FAKECHROOT_CMD_SUBST but /usr/sbin (the actual location of the chroot
binary) is not in PATH, the command fails
This commit is contained in:
Johannes Schauer Marin Rodrigues 2022-05-29 07:50:10 +02:00
parent 158956e213
commit e4ef326b59
Signed by untrusted user: josch
GPG key ID: F2CBA5C78FBD83E1
3 changed files with 41 additions and 9 deletions

View file

@ -312,3 +312,6 @@ Skip-If:
hostarch != "amd64" hostarch != "amd64"
mode == "fakechroot" and not run_ma_same_tests mode == "fakechroot" and not run_ma_same_tests
not have_binfmt not have_binfmt
Test: no-sbin-in-path
Modes: fakechroot

View file

@ -2346,17 +2346,24 @@ sub run_prepare {
# /etc/fakechroot/debootstrap.env and # /etc/fakechroot/debootstrap.env and
# /etc/fakechroot/chroot.env # /etc/fakechroot/chroot.env
{ {
my $ldconfig = getcwd() . '/ldconfig.fakechroot'; my %subst = (
if (!-x $ldconfig) { chroot => "/usr/sbin/chroot.fakechroot",
$ldconfig = '/usr/libexec/mmdebstrap/ldconfig.fakechroot'; mkfifo => "/bin/true",
ldconfig => (getcwd() . '/ldconfig.fakechroot'),
ldd => "/usr/bin/ldd.fakechroot",
ischroot => "/bin/true"
);
if (!-x $subst{ldconfig}) {
$subst{ldconfig}
= '/usr/libexec/mmdebstrap/ldconfig.fakechroot';
} }
my @fakechrootsubst = (); my @fakechrootsubst = ();
foreach my $d ('/usr/sbin', '/usr/bin', '/sbin', '/bin') { foreach my $d (split ':', $ENV{PATH}) {
push @fakechrootsubst, "$d/chroot=/usr/sbin/chroot.fakechroot"; foreach my $k (sort keys %subst) {
push @fakechrootsubst, "$d/mkfifo=/bin/true"; if (-e "$d/$k") {
push @fakechrootsubst, "$d/ldconfig=$ldconfig"; push @fakechrootsubst, "$d/$k=$subst{$k}";
push @fakechrootsubst, "$d/ldd=/usr/bin/ldd.fakechroot"; }
push @fakechrootsubst, "$d/ischroot=/bin/true"; }
} }
if (defined $ENV{FAKECHROOT_CMD_SUBST} if (defined $ENV{FAKECHROOT_CMD_SUBST}
&& $ENV{FAKECHROOT_CMD_SUBST} ne "") { && $ENV{FAKECHROOT_CMD_SUBST} ne "") {

22
tests/no-sbin-in-path Normal file
View file

@ -0,0 +1,22 @@
#!/bin/sh
#
# If FAKECHROOT_CMD_SUBST sets up wrong substitutions, then binaries cannot be
# found. For example if /usr/bin/chroot is listed in FAKECHROOT_CMD_SUBST but
# /usr/sbin (the actual location of the chroot binary) is not in PATH, the
# command fails
set -eu
export LC_ALL=C.UTF-8
[ "{{ MODE }}" = "fakechroot" ]
trap "rm -f /tmp/debian-chroot.tar" EXIT INT TERM
if [ "$(id -u)" -eq 0 ] && ! id -u user > /dev/null 2>&1; then
if [ ! -e /mmdebstrap-testenv ]; then
echo "this test modifies the system and should only be run inside a container" >&2
exit 1
fi
adduser --gecos user --disabled-password user
fi
prefix=
[ "$(id -u)" -eq 0 ] && prefix="runuser -u user --"
$prefix env PATH=/usr/bin:/bin fakechroot fakeroot {{ CMD }} --mode=fakechroot --variant=apt {{ DIST }} /tmp/debian-chroot.tar {{ MIRROR }}
tar -tf /tmp/debian-chroot.tar | sort | diff -u tar1.txt -