On 3/10/2021 8:09 AM, Mickaël Salaün wrote: > Hi, > > 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: > https://lore.kernel.org/lkml/0e2f0f54e19bff53a3739ecfddb4ffa9a6dbde4d.1327858005.git.luto@xxxxxxxxxxxxxx/ > > This patch can be applied on top of v5.12-rc2 . I would really > appreciate constructive reviews. > > Regards, > > 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
