From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- net/sunrpc/auth_null.c | 143 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 143 insertions(+) create mode 100644 net/sunrpc/auth_null.c (limited to 'net/sunrpc/auth_null.c') diff --git a/net/sunrpc/auth_null.c b/net/sunrpc/auth_null.c new file mode 100644 index 000000000..41a633a40 --- /dev/null +++ b/net/sunrpc/auth_null.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/net/sunrpc/auth_null.c + * + * AUTH_NULL authentication. Really :-) + * + * Copyright (C) 1996, Olaf Kirch + */ + +#include +#include +#include + +#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) +# define RPCDBG_FACILITY RPCDBG_AUTH +#endif + +static struct rpc_auth null_auth; +static struct rpc_cred null_cred; + +static struct rpc_auth * +nul_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt) +{ + refcount_inc(&null_auth.au_count); + return &null_auth; +} + +static void +nul_destroy(struct rpc_auth *auth) +{ +} + +/* + * Lookup NULL creds for current process + */ +static struct rpc_cred * +nul_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) +{ + return get_rpccred(&null_cred); +} + +/* + * Destroy cred handle. + */ +static void +nul_destroy_cred(struct rpc_cred *cred) +{ +} + +/* + * Match cred handle against current process + */ +static int +nul_match(struct auth_cred *acred, struct rpc_cred *cred, int taskflags) +{ + return 1; +} + +/* + * Marshal credential. + */ +static int +nul_marshal(struct rpc_task *task, struct xdr_stream *xdr) +{ + __be32 *p; + + p = xdr_reserve_space(xdr, 4 * sizeof(*p)); + if (!p) + return -EMSGSIZE; + /* Credential */ + *p++ = rpc_auth_null; + *p++ = xdr_zero; + /* Verifier */ + *p++ = rpc_auth_null; + *p = xdr_zero; + return 0; +} + +/* + * Refresh credential. This is a no-op for AUTH_NULL + */ +static int +nul_refresh(struct rpc_task *task) +{ + set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags); + return 0; +} + +static int +nul_validate(struct rpc_task *task, struct xdr_stream *xdr) +{ + __be32 *p; + + p = xdr_inline_decode(xdr, 2 * sizeof(*p)); + if (!p) + return -EIO; + if (*p++ != rpc_auth_null) + return -EIO; + if (*p != xdr_zero) + return -EIO; + return 0; +} + +const struct rpc_authops authnull_ops = { + .owner = THIS_MODULE, + .au_flavor = RPC_AUTH_NULL, + .au_name = "NULL", + .create = nul_create, + .destroy = nul_destroy, + .lookup_cred = nul_lookup_cred, +}; + +static +struct rpc_auth null_auth = { + .au_cslack = NUL_CALLSLACK, + .au_rslack = NUL_REPLYSLACK, + .au_verfsize = NUL_REPLYSLACK, + .au_ralign = NUL_REPLYSLACK, + .au_ops = &authnull_ops, + .au_flavor = RPC_AUTH_NULL, + .au_count = REFCOUNT_INIT(1), +}; + +static +const struct rpc_credops null_credops = { + .cr_name = "AUTH_NULL", + .crdestroy = nul_destroy_cred, + .crmatch = nul_match, + .crmarshal = nul_marshal, + .crwrap_req = rpcauth_wrap_req_encode, + .crrefresh = nul_refresh, + .crvalidate = nul_validate, + .crunwrap_resp = rpcauth_unwrap_resp_decode, +}; + +static +struct rpc_cred null_cred = { + .cr_lru = LIST_HEAD_INIT(null_cred.cr_lru), + .cr_auth = &null_auth, + .cr_ops = &null_credops, + .cr_count = REFCOUNT_INIT(2), + .cr_flags = 1UL << RPCAUTH_CRED_UPTODATE, +}; -- cgit v1.3.1