[PATCH AUTOSEL 5.6 263/606] gfs2: move privileged user check to gfs2_quota_lock_check

Sasha Levin
2020-06-08T23:22:07Z

From: Bob Peterson <rpeterso@redhat.com>

[ Upstream commit 4ed0c30811cb4d30ef89850b787a53a84d5d2bcb ]

Before this patch, function gfs2_quota_lock checked if it was called
from a privileged user, and if so, it bypassed the quota check:
superuser can operate outside the quotas.
That's the wrong place for the check because the lock/unlock functions
are separate from the lock_check function, and you can do lock and
unlock without actually checking the quotas.

This patch moves the check to gfs2_quota_lock_check.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/gfs2/quota.c | 3 +--
fs/gfs2/quota.h | 3 ++-
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index e9f93045eb01..832d44782f74 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -1040,8 +1040,7 @@ int gfs2_quota_lock(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
u32 x;
int error = 0;

- if (capable(CAP_SYS_RESOURCE) ||
- sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
+ if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
return 0;

error = gfs2_quota_hold(ip, uid, gid);
diff --git a/fs/gfs2/quota.h b/fs/gfs2/quota.h
index 765627d9a91e..fe68a91dc16f 100644
--- a/fs/gfs2/quota.h
+++ b/fs/gfs2/quota.h
@@ -44,7 +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 (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
+ if (capable(CAP_SYS_RESOURCE) ||
+ sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
return 0;
ret = gfs2_quota_lock(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
if (ret)
--
2.25.1