From: Luis Henriques <lhenriques@suse.com>
Date: Mon, 5 Nov 2018 19:00:52 +0000
Subject: ceph: quota: fix null pointer dereference in quota check
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Git-commit: 71f2cc64d027d712f29bf8d09d3e123302d5f245
Patch-mainline: v4.20-rc2
References: bsc#1114839
This patch fixes a possible null pointer dereference in
check_quota_exceeded, detected by the static checker smatch, with the
following warning:
fs/ceph/quota.c:240 check_quota_exceeded()
error: we previously assumed 'realm' could be null (see line 188)
Fixes: b7a2921765cf ("ceph: quota: support for ceph.quota.max_files")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
fs/ceph/quota.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c
index 32d4f13784ba..03f4d24db8fe 100644
--- a/fs/ceph/quota.c
+++ b/fs/ceph/quota.c
@@ -237,7 +237,8 @@ static bool check_quota_exceeded(struct inode *inode, enum quota_check_op op,
ceph_put_snap_realm(mdsc, realm);
realm = next;
}
- ceph_put_snap_realm(mdsc, realm);
+ if (realm)
+ ceph_put_snap_realm(mdsc, realm);
up_read(&mdsc->snap_rwsem);
return exceeded;