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/apparmor/ipc.c | 116 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 116 insertions(+) create mode 100644 security/apparmor/ipc.c (limited to 'security/apparmor/ipc.c') diff --git a/security/apparmor/ipc.c b/security/apparmor/ipc.c new file mode 100644 index 000000000..df5712cea --- /dev/null +++ b/security/apparmor/ipc.c @@ -0,0 +1,116 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor ipc mediation + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2017 Canonical Ltd. + */ + +#include + +#include "include/audit.h" +#include "include/capability.h" +#include "include/cred.h" +#include "include/policy.h" +#include "include/ipc.h" +#include "include/sig_names.h" + + +static inline int map_signal_num(int sig) +{ + if (sig > SIGRTMAX) + return SIGUNKNOWN; + else if (sig >= SIGRTMIN) + return sig - SIGRTMIN + SIGRT_BASE; + else if (sig < MAXMAPPED_SIG) + return sig_map[sig]; + return SIGUNKNOWN; +} + +/** + * audit_signal_mask - convert mask to permission string + * @mask: permission mask to convert + * + * Returns: pointer to static string + */ +static const char *audit_signal_mask(u32 mask) +{ + if (mask & MAY_READ) + return "receive"; + if (mask & MAY_WRITE) + return "send"; + return ""; +} + +/** + * audit_signal_cb() - call back for signal specific audit fields + * @ab: audit_buffer (NOT NULL) + * @va: audit struct to audit values of (NOT NULL) + */ +static void audit_signal_cb(struct audit_buffer *ab, void *va) +{ + struct common_audit_data *sa = va; + struct apparmor_audit_data *ad = aad(sa); + + if (ad->request & AA_SIGNAL_PERM_MASK) { + audit_log_format(ab, " requested_mask=\"%s\"", + audit_signal_mask(ad->request)); + if (ad->denied & AA_SIGNAL_PERM_MASK) { + audit_log_format(ab, " denied_mask=\"%s\"", + audit_signal_mask(ad->denied)); + } + } + if (ad->signal == SIGUNKNOWN) + audit_log_format(ab, "signal=unknown(%d)", + ad->unmappedsig); + else if (ad->signal < MAXMAPPED_SIGNAME) + audit_log_format(ab, " signal=%s", sig_names[ad->signal]); + else + audit_log_format(ab, " signal=rtmin+%d", + ad->signal - SIGRT_BASE); + audit_log_format(ab, " peer="); + aa_label_xaudit(ab, labels_ns(ad->subj_label), ad->peer, + FLAGS_NONE, GFP_ATOMIC); +} + +static int profile_signal_perm(const struct cred *cred, + struct aa_profile *profile, + struct aa_label *peer, u32 request, + struct apparmor_audit_data *ad) +{ + struct aa_ruleset *rules = profile->label.rules[0]; + struct aa_perms perms; + aa_state_t state; + + if (profile_unconfined(profile)) + return 0; + + ad->subj_cred = cred; + ad->peer = peer; + /* TODO: secondary cache check */ + state = RULE_MEDIATES(rules, AA_CLASS_SIGNAL); + if (!state) + return 0; + state = aa_dfa_next(rules->policy->dfa, state, ad->signal); + aa_label_match(profile, rules, peer, state, false, request, &perms); + aa_apply_modes_to_perms(profile, &perms); + return aa_check_perms(profile, &perms, request, ad, audit_signal_cb); +} + +int aa_may_signal(const struct cred *subj_cred, struct aa_label *sender, + const struct cred *target_cred, struct aa_label *target, + int sig) +{ + struct aa_profile *profile; + DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_SIGNAL, OP_SIGNAL); + + ad.signal = map_signal_num(sig); + ad.unmappedsig = sig; + return xcheck_labels(sender, target, profile, + profile_signal_perm(subj_cred, profile, target, + MAY_WRITE, &ad), + profile_signal_perm(target_cred, profile, sender, + MAY_READ, &ad)); +} -- cgit v1.3.1