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| author | Chuck Lever <chuck.lever@oracle.com> | 2017-08-10 16:41:31 -0400 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2017-08-20 12:43:34 -0400 |
| commit | 53a75f22e78a601321c2e1fd16266ecdae2f2309 (patch) | |
| tree | 29e1691dc4353792cf2793934a817756da1bbe64 /fs | |
| parent | b79e87e070476e16b1d687e5ccc2da6db1a839dc (diff) | |
| download | linux-53a75f22e78a601321c2e1fd16266ecdae2f2309.tar.gz | |
NFS: Fix NFSv2 security settings
For a while now any NFSv2 mount where sec= is specified uses
AUTH_NULL. If sec= is not specified, the mount uses AUTH_UNIX.
Commit e68fd7c8071d ("mount: use sec= that was specified on the
command line") attempted to address a very similar problem with
NFSv3, and should have fixed this too, but it has a bug.
The MNTv1 MNT procedure does not return a list of security flavors,
so our client makes up a list containing just AUTH_NULL. This should
enable nfs_verify_authflavors() to assign the sec= specified flavor,
but instead, it incorrectly sets it to AUTH_NULL.
I expect this would also be a problem for any NFSv3 server whose
MNTv3 MNT procedure returned a security flavor list containing only
AUTH_NULL.
Fixes: e68fd7c8071d ("mount: use sec= that was specified on ... ")
BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=310
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfs/super.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/fs/nfs/super.c b/fs/nfs/super.c index d828ef88e7db..6b179af59b92 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -1691,8 +1691,8 @@ static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args, rpc_authflavor_t *server_authlist, unsigned int count) { rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR; + bool found_auth_null = false; unsigned int i; - int use_auth_null = false; /* * If the sec= mount option is used, the specified flavor or AUTH_NULL @@ -1701,6 +1701,10 @@ static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args, * AUTH_NULL has a special meaning when it's in the server list - it * means that the server will ignore the rpc creds, so any flavor * can be used but still use the sec= that was specified. + * + * Note also that the MNT procedure in MNTv1 does not return a list + * of supported security flavors. In this case, nfs_mount() fabricates + * a security flavor list containing just AUTH_NULL. */ for (i = 0; i < count; i++) { flavor = server_authlist[i]; @@ -1709,11 +1713,11 @@ static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args, goto out; if (flavor == RPC_AUTH_NULL) - use_auth_null = true; + found_auth_null = true; } - if (use_auth_null) { - flavor = RPC_AUTH_NULL; + if (found_auth_null) { + flavor = args->auth_info.flavors[0]; goto out; } |