From 3fd9f902c08a9506f24c0857c2cb321d3d72c8dc Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 28 Apr 2020 08:10:22 -0400 Subject: ceph: fix endianness bug when handling MDS session feature bits commit 0fa8263367db9287aa0632f96c1a5f93cc478150 upstream. Eduard reported a problem mounting cephfs on s390 arch. The feature mask sent by the MDS is little-endian, so we need to convert it before storing and testing against it. Cc: stable@vger.kernel.org Reported-and-Tested-by: Eduard Shishkin Signed-off-by: Jeff Layton Reviewed-by: "Yan, Zheng" Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman --- fs/ceph/mds_client.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'fs') diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 8c1f04c3a684..b79fe6549df6 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -3072,8 +3072,7 @@ static void handle_session(struct ceph_mds_session *session, void *end = p + msg->front.iov_len; struct ceph_mds_session_head *h; u32 op; - u64 seq; - unsigned long features = 0; + u64 seq, features = 0; int wake = 0; bool blacklisted = false; @@ -3092,9 +3091,8 @@ static void handle_session(struct ceph_mds_session *session, goto bad; /* version >= 3, feature bits */ ceph_decode_32_safe(&p, end, len, bad); - ceph_decode_need(&p, end, len, bad); - memcpy(&features, p, min_t(size_t, len, sizeof(features))); - p += len; + ceph_decode_64_safe(&p, end, features, bad); + p += len - sizeof(features); } mutex_lock(&mdsc->mutex); -- cgit v1.2.3