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/ipe/digest.c | 119 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 security/ipe/digest.c (limited to 'security/ipe/digest.c') diff --git a/security/ipe/digest.c b/security/ipe/digest.c new file mode 100644 index 000000000..6e597a6b7 --- /dev/null +++ b/security/ipe/digest.c @@ -0,0 +1,119 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved. + */ + +#include +#include "digest.h" + +/** + * ipe_digest_parse() - parse a digest in IPE's policy. + * @valstr: Supplies the string parsed from the policy. + * + * Digests in IPE are defined in a standard way: + * : + * + * Use this function to create a property to parse the digest + * consistently. The parsed digest will be saved in @value in IPE's + * policy. + * + * Return: The parsed digest_info structure on success. If an error occurs, + * the function will return the error value (via ERR_PTR). + */ +struct digest_info *ipe_digest_parse(const char *valstr) +{ + struct digest_info *info = NULL; + char *sep, *raw_digest; + size_t raw_digest_len; + u8 *digest = NULL; + char *alg = NULL; + int rc = 0; + + info = kzalloc_obj(*info); + if (!info) + return ERR_PTR(-ENOMEM); + + sep = strchr(valstr, ':'); + if (!sep) { + rc = -EBADMSG; + goto err; + } + + alg = kstrndup(valstr, sep - valstr, GFP_KERNEL); + if (!alg) { + rc = -ENOMEM; + goto err; + } + + raw_digest = sep + 1; + raw_digest_len = strlen(raw_digest); + + info->digest_len = (raw_digest_len + 1) / 2; + digest = kzalloc(info->digest_len, GFP_KERNEL); + if (!digest) { + rc = -ENOMEM; + goto err; + } + + rc = hex2bin(digest, raw_digest, info->digest_len); + if (rc < 0) { + rc = -EINVAL; + goto err; + } + + info->alg = alg; + info->digest = digest; + return info; + +err: + kfree(alg); + kfree(digest); + kfree(info); + return ERR_PTR(rc); +} + +/** + * ipe_digest_eval() - evaluate an IPE digest against another digest. + * @expected: Supplies the policy-provided digest value. + * @digest: Supplies the digest to compare against the policy digest value. + * + * Return: + * * %true - digests match + * * %false - digests do not match + */ +bool ipe_digest_eval(const struct digest_info *expected, + const struct digest_info *digest) +{ + return (expected->digest_len == digest->digest_len) && + (!strcmp(expected->alg, digest->alg)) && + (!memcmp(expected->digest, digest->digest, expected->digest_len)); +} + +/** + * ipe_digest_free() - free an IPE digest. + * @info: Supplies a pointer the policy-provided digest to free. + */ +void ipe_digest_free(struct digest_info *info) +{ + if (IS_ERR_OR_NULL(info)) + return; + + kfree(info->alg); + kfree(info->digest); + kfree(info); +} + +/** + * ipe_digest_audit() - audit a digest that was sourced from IPE's policy. + * @ab: Supplies the audit_buffer to append the formatted result. + * @info: Supplies a pointer to source the audit record from. + * + * Digests in IPE are audited in this format: + * : + */ +void ipe_digest_audit(struct audit_buffer *ab, const struct digest_info *info) +{ + audit_log_untrustedstring(ab, info->alg); + audit_log_format(ab, ":"); + audit_log_n_hex(ab, info->digest, info->digest_len); +} -- cgit v1.3.1