4.19-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 71f2cc64d027d712f29bf8d09d3e123302d5f245 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- 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;