On Mon, 2022-05-23 at 17:09 +0100, Luís Henriques wrote:
> The cephfs kernel client started to show the message:
>
> ceph: mds0 session blocklisted
>
> when mounting a filesystem. This is due to the fact that the session
> messages are being incorrectly decoded: the skip needs to take into
> account the 'len'.
>
> While there, fixed some whitespaces too.
>
> Fixes: e1c9788cb397 ("ceph: don't rely on error_string to validate blocklisted session.")
> Signed-off-by: Luís Henriques <lhenriques@xxxxxxx>
> ---
> fs/ceph/mds_client.c | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
> index 00c3de177dd6..1bd3e1bb0fdf 100644
> --- a/fs/ceph/mds_client.c
> +++ b/fs/ceph/mds_client.c
> @@ -3375,13 +3375,17 @@ static void handle_session(struct ceph_mds_session *session,
> }
>
> if (msg_version >= 5) {
> - u32 flags;
> - /* version >= 4, struct_v, struct_cv, len, metric_spec */
> - ceph_decode_skip_n(&p, end, 2 + sizeof(u32) * 2, bad);
> + u32 flags, len;
> +
> + /* version >= 4 */
> + ceph_decode_skip_16(&p, end, bad); /* struct_v, struct_cv */
> + ceph_decode_32_safe(&p, end, len, bad); /* len */
> + ceph_decode_skip_n(&p, end, len, bad); /* metric_spec */
> +
> /* version >= 5, flags */
> - ceph_decode_32_safe(&p, end, flags, bad);
> + ceph_decode_32_safe(&p, end, flags, bad);
> if (flags & CEPH_SESSION_BLOCKLISTED) {
> - pr_warn("mds%d session blocklisted\n", session->s_mds);
> + pr_warn("mds%d session blocklisted\n", session->s_mds);
> blocklisted = true;
> }
> }
Good catch! Should we send this to stable too?
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
