From eb54d43707c69340581940e1fcaecb4d7d17b814 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 14 May 2013 14:37:56 -0400 Subject: [PATCH] NFS: Fix security flavor negotiation with legacy binary mounts Darrick J. Wong reports: > I have a kvm-based testing setup that netboots VMs over NFS, the > client end of which seems to have broken somehow in 3.10-rc1. The > server's exports file looks like this: > > /storage/mtr/x64 192.168.122.0/24(ro,sync,no_root_squash,no_subtree_check) > > On the client end (inside the VM), the initrd runs the following > command to try to mount the rootfs over NFS: > > # mount -o nolock -o ro -o retrans=10 192.168.122.1:/storage/mtr/x64/ /root > > (Note: This is the busybox mount command.) > > The mount fails with -EINVAL. Commit 4580a92d44 "NFS: Use server-recommended security flavor by default (NFSv3)" introduced a behavior regression for NFS mounts done via a legacy binary mount(2) call. Ensure that a default security flavor is specified for legacy binary mount requests, since they do not invoke nfs_select_flavor() in the kernel. Busybox uses klibc's nfsmount command, which performs NFS mounts using the legacy binary mount data format. /sbin/mount.nfs is not affected by this regression. Reported-by: Darrick J. Wong Signed-off-by: Chuck Lever Tested-by: Darrick J. Wong Acked-by: Weston Andros Adamson Signed-off-by: Trond Myklebust --- fs/nfs/super.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/nfs/super.c b/fs/nfs/super.c index a366107a7331..2d7525fbcf25 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -1942,6 +1942,7 @@ static int nfs23_validate_mount_data(void *options, args->namlen = data->namlen; args->bsize = data->bsize; + args->auth_flavors[0] = RPC_AUTH_UNIX; if (data->flags & NFS_MOUNT_SECFLAVOUR) args->auth_flavors[0] = data->pseudoflavor; if (!args->nfs_server.hostname) @@ -2637,6 +2638,7 @@ static int nfs4_validate_mount_data(void *options, goto out_no_address; args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port); + args->auth_flavors[0] = RPC_AUTH_UNIX; if (data->auth_flavourlen) { if (data->auth_flavourlen > 1) goto out_inval_auth; -- 2.20.1