[PATCH v1 0/1] Unprivileged chroot
casey at schaufler-ca.com
Wed Mar 10 17:22:16 UTC 2021
On 3/10/2021 8:09 AM, Mickaël Salaün wrote:
> 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).
Mount namespaces have pretty well obsoleted chroot(). CAP_SYS_CHROOT is
one of the few fine grained capabilities. We're still finding edge cases
(e.g. ptrace) where no_new_privs is imperfect. I doesn't seem that there
is a compelling reason to remove the privilege requirement on chroot().
> This patch is a follow-up of a previous one sent by Andy Lutomirski some
> time ago:
> This patch can be applied on top of v5.12-rc2 . I would really
> appreciate constructive reviews.
> Mickaël Salaün (1):
> fs: Allow no_new_privs tasks to call chroot(2)
> fs/open.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 61 insertions(+), 3 deletions(-)
> base-commit: a38fd8748464831584a19438cbb3082b5a2dab15
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