[SOLVED] chroot: failed to run command '/bin/bash': Permission denied

AlleyTrotter · 10-18-2012, 10:13 AM

I have tried to use the short sequence of commands I found on the Arch doc's site to chroot into my rescue partition.
I am getting the error as in the post title

Code:

# cd /mnt/rescue
# mount -t proc proc proc/
# mount -t sysfs sys sys/
# mount -o bind /dev dev/
# mount -t devpts pts dev/pts/
# chroot . /bin/bash

My system is a complete slackware64-14.0 installed from scratch on /dev/sda. A few packages from sbo have been added :
aide/
celt051/
jdk/
kde/
kmymoney/
libalkimia/
libcacard/
libofx/
libreoffice/
pyparsing/
qemu-kvm/
sbopkg/
spice/
spice-protocol/
src2pkg/
usbredir/
using kernel 3.6.2 and PV's config from /testing

rescue is its own partition on /dev/sdb with a complete cherry slackware64-14.0 installed.
I was hoping to use the above sequence to use the 'upgradepkg' command to perform security updates on my rescue partition without rebooting.

As suggested by Didier-Spaier in a similiar post "Additionally you should use the "-o bind" option for all "mount" commands but AFAIK there is no need to mount devpts."

Code:

# mount -o bind /proc proc/
# mount -o bind /sys sys/
# mount -o bind /dev dev/
# chroot . /bin/bash

Also tried without /bin/bash
Also tried with bin/bash
same error "chroot: failed to run command '/bin/bash': Permission Denied"

'bash' exists and is executable

Code:

ls -l /mnt/rescue/bin/bash
-rwxr-xr-x 1 root root 986120 Aug 10 18:09 /mnt/rescue/bin/bash*

any suggestions would be appreciated
thanks
john

TommyC7 · 10-18-2012, 10:32 AM

http://docs.slackware.com/howtos:sla...oot_from_media

Does that wiki page describe what you're looking for?

kabamaru · 10-18-2012, 10:39 AM

Is the rescue partition mounted 'noexec' ?

AlleyTrotter · 10-18-2012, 12:25 PM

Quote:

Originally Posted by kabamaru

Is the rescue partition mounted 'noexec' ?

the pertinent line from fstab

Code:

/dev/sdb2       /mnt/rescue     ext4    noauto,noatime,users,rw                 1   2

Quote:

Does that wiki page describe what you're looking for?

from the wiki page

Code:

mount -o bind /dev /mnt/rescue/dev
mount -o bind /proc /mnt/rescue/proc
mount -o bind /sys /mnt/rescue/sys

Identical error
Thanks for the suggestions, but no cigar.
John

kabamaru · 10-18-2012, 01:25 PM

From mount's manpage, regarding the 'users' option in fstab:

Quote:

users

Allow every user to mount and unmount the filesystem. This option implies the options noexec, nosuid, and nodev (unless overridden by subsequent options, as in the option line users,exec,dev,suid).

AlleyTrotter · 10-18-2012, 04:09 PM

Quote:

Originally Posted by kabamaru

From mount's manpage, regarding the 'users' option in fstab:

Many thanks!
Adding 'exec' after 'users' in fstab did the trick in conjunction with '-o bind'

actually I changed the whole stanza

Code:

 /dev/sdb2 /mnt/rescue ext4 defaults 1 2

no need for any users to mount rescue

Why didn't I know that.

John