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/bpf/Makefile | 5 +++++ security/bpf/hooks.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 47 insertions(+) create mode 100644 security/bpf/Makefile create mode 100644 security/bpf/hooks.c (limited to 'security/bpf') diff --git a/security/bpf/Makefile b/security/bpf/Makefile new file mode 100644 index 000000000..c7a89a962 --- /dev/null +++ b/security/bpf/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright (C) 2020 Google LLC. + +obj-$(CONFIG_BPF_LSM) := hooks.o diff --git a/security/bpf/hooks.c b/security/bpf/hooks.c new file mode 100644 index 000000000..7b98f5d1e --- /dev/null +++ b/security/bpf/hooks.c @@ -0,0 +1,42 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2020 Google LLC. + */ +#include +#include +#include + +bool bpf_lsm_initialized __ro_after_init; + +static struct security_hook_list bpf_lsm_hooks[] __ro_after_init = { + #define LSM_HOOK(RET, DEFAULT, NAME, ...) \ + LSM_HOOK_INIT(NAME, bpf_lsm_##NAME), + #include + #undef LSM_HOOK + LSM_HOOK_INIT(inode_free_security, bpf_inode_storage_free), +}; + +static const struct lsm_id bpf_lsmid = { + .name = "bpf", + .id = LSM_ID_BPF, +}; + +static int __init bpf_lsm_init(void) +{ + security_add_hooks(bpf_lsm_hooks, ARRAY_SIZE(bpf_lsm_hooks), + &bpf_lsmid); + bpf_lsm_initialized = true; + pr_info("LSM support for eBPF active\n"); + return 0; +} + +struct lsm_blob_sizes bpf_lsm_blob_sizes __ro_after_init = { + .lbs_inode = sizeof(struct bpf_storage_blob), +}; + +DEFINE_LSM(bpf) = { + .id = &bpf_lsmid, + .init = bpf_lsm_init, + .blobs = &bpf_lsm_blob_sizes +}; -- cgit v1.3.1