Some releases of Linux rpc.mountd (nfs-utils 1.1.4 and later) return an empty auth flavor list if no sec= was specified for the export. This is notably broken server behavior. The new auth flavor list checking added in a recent commit rejects this case. The OpenSolaris client does too. The broken mountd implementation is already widely deployed. To avoid a behavioral regression, the kernel's mount client skips flavor checking (ie reverts to the pre-2.6.32 behavior) if mountd returns an empty flavor list. Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> --- Trond- First proposal to address the empty flavor list regression. fs/nfs/super.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-) diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 9c85cdb..f3a95df 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -1338,6 +1338,16 @@ static int nfs_walk_authlist(struct nfs_parsed_mount_data *args, unsigned int i, j, server_authlist_len = *(request->auth_flav_len); /* + * Certain releases of Linux's mountd return an empty + * flavor list. To prevent behavioral regression with + * these servers (ie. rejecting mounts that used to + * succeed), revert to pre-2.6.32 behavior (no checking) + * if the returned flavor list is empty. + */ + if (server_authlist_len == 0) + return 0; + + /* * We avoid sophisticated negotiating here, as there are * plenty of cases where we can get it wrong, providing * either too little or too much security. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
