[PATCH v3 0/1] Unprivileged chroot

Mickaël Salaün mic at digikod.net
Thu Mar 11 10:52:41 UTC 2021


Hi,

This new patch replaces the path_is_under() check with
current_chrooted() as it is done with user namespaces.  Indeed, it is
much more simple to check the current root instead of limiting access to
a subset of files.

The chroot system call is currently limited to be used by processes with
the CAP_SYS_CHROOT capability.  This protects against malicious
procesess willing to trick SUID-like binaries.  The following patch
allows unprivileged users to safely use chroot(2), which may be
complementary to the use of user namespaces.

This patch is a follow-up of a previous one sent by Andy Lutomirski some
time ago:
https://lore.kernel.org/lkml/0e2f0f54e19bff53a3739ecfddb4ffa9a6dbde4d.1327858005.git.luto@amacapital.net/

This patch can be applied on top of v5.12-rc2 .  I would really
appreciate constructive reviews.

Previous version:
https://lore.kernel.org/r/20210310181857.401675-1-mic@digikod.net

Regards,

Mickaël Salaün (1):
  fs: Allow no_new_privs tasks to call chroot(2)

 fs/open.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)


base-commit: a38fd8748464831584a19438cbb3082b5a2dab15
-- 
2.30.2



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