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| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-06-09 16:15:46 -0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-07-10 23:40:34 -0400 |
| commit | fc1b356f566fe05929ec2a88ce2c7b15f8b6279f (patch) | |
| tree | 7d790ea2d3618b9cb166081a86797411f3547e44 /net/sunrpc/auth.c | |
| parent | 07a2bf1da4765d987ffd1d8045e92ba032e0ad78 (diff) | |
| download | lwn-fc1b356f566fe05929ec2a88ce2c7b15f8b6279f.tar.gz lwn-fc1b356f566fe05929ec2a88ce2c7b15f8b6279f.zip | |
SUNRPC: Fix races in rpcauth_create
See the FIXME: auth_flavors[] really needs a lock and module refcounting.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'net/sunrpc/auth.c')
| -rw-r--r-- | net/sunrpc/auth.c | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c index f6b6c81cbc3e..584f24311a80 100644 --- a/net/sunrpc/auth.c +++ b/net/sunrpc/auth.c @@ -18,6 +18,7 @@ # define RPCDBG_FACILITY RPCDBG_AUTH #endif +static DEFINE_SPINLOCK(rpc_authflavor_lock); static struct rpc_authops * auth_flavors[RPC_AUTH_MAXFLAVOR] = { &authnull_ops, /* AUTH_NULL */ &authunix_ops, /* AUTH_UNIX */ @@ -35,26 +36,34 @@ int rpcauth_register(struct rpc_authops *ops) { rpc_authflavor_t flavor; + int ret = -EPERM; if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR) return -EINVAL; - if (auth_flavors[flavor] != NULL) - return -EPERM; /* what else? */ - auth_flavors[flavor] = ops; - return 0; + spin_lock(&rpc_authflavor_lock); + if (auth_flavors[flavor] == NULL) { + auth_flavors[flavor] = ops; + ret = 0; + } + spin_unlock(&rpc_authflavor_lock); + return ret; } int rpcauth_unregister(struct rpc_authops *ops) { rpc_authflavor_t flavor; + int ret = -EPERM; if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR) return -EINVAL; - if (auth_flavors[flavor] != ops) - return -EPERM; /* what else? */ - auth_flavors[flavor] = NULL; - return 0; + spin_lock(&rpc_authflavor_lock); + if (auth_flavors[flavor] == ops) { + auth_flavors[flavor] = NULL; + ret = 0; + } + spin_unlock(&rpc_authflavor_lock); + return ret; } struct rpc_auth * @@ -68,15 +77,19 @@ rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt) if (flavor >= RPC_AUTH_MAXFLAVOR) goto out; - /* FIXME - auth_flavors[] really needs an rw lock, - * and module refcounting. */ #ifdef CONFIG_KMOD if ((ops = auth_flavors[flavor]) == NULL) request_module("rpc-auth-%u", flavor); #endif - if ((ops = auth_flavors[flavor]) == NULL) + spin_lock(&rpc_authflavor_lock); + ops = auth_flavors[flavor]; + if (ops == NULL || !try_module_get(ops->owner)) { + spin_unlock(&rpc_authflavor_lock); goto out; + } + spin_unlock(&rpc_authflavor_lock); auth = ops->create(clnt, pseudoflavor); + module_put(ops->owner); if (IS_ERR(auth)) return auth; if (clnt->cl_auth) |