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| author | Jeff Layton <jlayton@kernel.org> | 2020-08-04 12:31:56 -0400 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2020-08-05 17:47:07 +0200 |
| commit | 02e37571f9e79022498fd0525c073b07e9d9ac69 (patch) | |
| tree | 115edaa75ee9b1084e7665b742a947a5b011fc3b /fs/ceph | |
| parent | 224c7b6778fe08e1880ef88867051bec0a154d6c (diff) | |
| download | linux-02e37571f9e79022498fd0525c073b07e9d9ac69.tar.gz | |
ceph: handle zero-length feature mask in session messages
Most session messages contain a feature mask, but the MDS will
routinely send a REJECT message with one that is zero-length.
Commit 0fa8263367db ("ceph: fix endianness bug when handling MDS
session feature bits") fixed the decoding of the feature mask,
but failed to account for the MDS sending a zero-length feature
mask. This causes REJECT message decoding to fail.
Skip trying to decode a feature mask if the word count is zero.
Cc: stable@vger.kernel.org
URL: https://tracker.ceph.com/issues/46823
Fixes: 0fa8263367db ("ceph: fix endianness bug when handling MDS session feature bits")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Patrick Donnelly <pdonnell@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'fs/ceph')
| -rw-r--r-- | fs/ceph/mds_client.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 1095802ad9bd..4a26862d7667 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -3358,8 +3358,10 @@ 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_64_safe(&p, end, features, bad); - p += len - sizeof(features); + if (len) { + ceph_decode_64_safe(&p, end, features, bad); + p += len - sizeof(features); + } } mutex_lock(&mdsc->mutex); |