From: Christian Göttsche Date: Mon, 25 Nov 2024 10:40:00 +0000 (+0100) Subject: gfs2: reorder capability check last X-Git-Tag: v6.14-rc1~208^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ead64b20f16e38443aded90dc8491d25f4f5bd39;p=thirdparty%2Flinux.git gfs2: reorder capability check last capable() calls refer to enabled LSMs whether to permit or deny the request. This is relevant in connection with SELinux, where a capability check results in a policy decision and by default a denial message on insufficient permission is issued. It can lead to three undesired cases: 1. A denial message is generated, even in case the operation was an unprivileged one and thus the syscall succeeded, creating noise. 2. To avoid the noise from 1. the policy writer adds a rule to ignore those denial messages, hiding future syscalls, where the task performs an actual privileged operation, leading to hidden limited functionality of that task. 3. To avoid the noise from 1. the policy writer adds a rule to permit the task the requested capability, while it does not need it, violating the principle of least privilege. Signed-off-by: Christian Göttsche Signed-off-by: Andreas Gruenbacher --- diff --git a/fs/gfs2/quota.h b/fs/gfs2/quota.h index f462d9cb30876..988f38dc5b2c0 100644 --- a/fs/gfs2/quota.h +++ b/fs/gfs2/quota.h @@ -44,8 +44,8 @@ static inline int gfs2_quota_lock_check(struct gfs2_inode *ip, int ret; ap->allowed = UINT_MAX; /* Assume we are permitted a whole lot */ - if (capable(CAP_SYS_RESOURCE) || - sdp->sd_args.ar_quota == GFS2_QUOTA_OFF) + if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF || + capable(CAP_SYS_RESOURCE)) return 0; ret = gfs2_quota_lock(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE); if (ret)