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 --- security/tomoyo/load_policy.c | 110 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 security/tomoyo/load_policy.c (limited to 'security/tomoyo/load_policy.c') diff --git a/security/tomoyo/load_policy.c b/security/tomoyo/load_policy.c new file mode 100644 index 000000000..363b65be8 --- /dev/null +++ b/security/tomoyo/load_policy.c @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/load_policy.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include "common.h" + +#ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER + +/* + * Path to the policy loader. (default = CONFIG_SECURITY_TOMOYO_POLICY_LOADER) + */ +static const char *tomoyo_loader; + +/** + * tomoyo_loader_setup - Set policy loader. + * + * @str: Program to use as a policy loader (e.g. /sbin/tomoyo-init ). + * + * Returns 0. + */ +static int __init tomoyo_loader_setup(char *str) +{ + tomoyo_loader = str; + return 1; +} + +__setup("TOMOYO_loader=", tomoyo_loader_setup); + +/** + * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists. + * + * Returns true if /sbin/tomoyo-init exists, false otherwise. + */ +static bool tomoyo_policy_loader_exists(void) +{ + struct path path; + + if (!tomoyo_loader) + tomoyo_loader = CONFIG_SECURITY_TOMOYO_POLICY_LOADER; + if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) { + pr_info("Not activating Mandatory Access Control as %s does not exist.\n", + tomoyo_loader); + return false; + } + path_put(&path); + return true; +} + +/* + * Path to the trigger. (default = CONFIG_SECURITY_TOMOYO_ACTIVATION_TRIGGER) + */ +static const char *tomoyo_trigger; + +/** + * tomoyo_trigger_setup - Set trigger for activation. + * + * @str: Program to use as an activation trigger (e.g. /sbin/init ). + * + * Returns 0. + */ +static int __init tomoyo_trigger_setup(char *str) +{ + tomoyo_trigger = str; + return 1; +} + +__setup("TOMOYO_trigger=", tomoyo_trigger_setup); + +/** + * tomoyo_load_policy - Run external policy loader to load policy. + * + * @filename: The program about to start. + * + * This function checks whether @filename is /sbin/init , and if so + * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init + * and then continues invocation of /sbin/init. + * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and + * writes to /sys/kernel/security/tomoyo/ interfaces. + * + * Returns nothing. + */ +void tomoyo_load_policy(const char *filename) +{ + static bool done; + char *argv[2]; + char *envp[3]; + + if (tomoyo_policy_loaded || done) + return; + if (!tomoyo_trigger) + tomoyo_trigger = CONFIG_SECURITY_TOMOYO_ACTIVATION_TRIGGER; + if (strcmp(filename, tomoyo_trigger)) + return; + if (!tomoyo_policy_loader_exists()) + return; + done = true; + pr_info("Calling %s to load policy. Please wait.\n", tomoyo_loader); + argv[0] = (char *) tomoyo_loader; + argv[1] = NULL; + envp[0] = "HOME=/"; + envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; + envp[2] = NULL; + call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC); + tomoyo_check_profile(); +} + +#endif -- cgit v1.3.1