staging: rtl8723bs: fix OOB read in rtw_action_frame_parse()grafted

rtw_action_frame_parse() takes a frame_len parameter but never
actually checks it before indexing into the frame body:

	const u8 *frame_body = frame + sizeof(struct ieee80211_hdr_3addr);
	...
	c = frame_body[0];
	...
	a = frame_body[1];

frame_body already points 24 bytes (sizeof(struct
ieee80211_hdr_3addr)) into frame, so reading frame_body[0] and
frame_body[1] requires frame_len >= 26. A management action frame
shorter than that (e.g. exactly 24 bytes, the minimum a malicious
peer can send) causes a 1-2 byte out-of-bounds read.

This is reachable from rtw_cfg80211_monitor_if_xmit_entry() and
cfg80211_rtw_mgmt_tx() in ioctl_cfg80211.c, both of which pass
attacker/user-influenced frame buffers and lengths straight through.

Add the missing length check before frame_body is dereferenced.

Fixes: 554c0a3abf216 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
Link: https://patch.msgid.link/20260728125456.32359-3-meatuni001@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 279 insertions, 0 deletions

diff --git a/security/ipe/audit.c b/security/ipe/audit.c
new file mode 100644
index 000000000..93fb59fbd
--- /dev/null
+++ b/security/ipe/audit.c
@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#include <linux/slab.h>
+#include <linux/audit.h>
+#include <linux/types.h>
+#include <crypto/sha2.h>
+
+#include "ipe.h"
+#include "eval.h"
+#include "hooks.h"
+#include "policy.h"
+#include "audit.h"
+#include "digest.h"
+
+#define ACTSTR(x) ((x) == IPE_ACTION_ALLOW ? "ALLOW" : "DENY")
+
+#define IPE_AUDIT_HASH_ALG "sha256" /* keep in sync with audit_policy() */
+
+#define AUDIT_POLICY_LOAD_FMT "policy_name=\"%s\" policy_version=%hu.%hu.%hu "\
+			      "policy_digest=" IPE_AUDIT_HASH_ALG ":"
+#define AUDIT_POLICY_LOAD_NULL_FMT "policy_name=? policy_version=? "\
+				   "policy_digest=?"
+#define AUDIT_OLD_ACTIVE_POLICY_FMT "old_active_pol_name=\"%s\" "\
+				    "old_active_pol_version=%hu.%hu.%hu "\
+				    "old_policy_digest=" IPE_AUDIT_HASH_ALG ":"
+#define AUDIT_OLD_ACTIVE_POLICY_NULL_FMT "old_active_pol_name=? "\
+					 "old_active_pol_version=? "\
+					 "old_policy_digest=?"
+#define AUDIT_NEW_ACTIVE_POLICY_FMT "new_active_pol_name=\"%s\" "\
+				    "new_active_pol_version=%hu.%hu.%hu "\
+				    "new_policy_digest=" IPE_AUDIT_HASH_ALG ":"
+
+static const char *const audit_op_names[__IPE_OP_MAX + 1] = {
+	"EXECUTE",
+	"FIRMWARE",
+	"KMODULE",
+	"KEXEC_IMAGE",
+	"KEXEC_INITRAMFS",
+	"POLICY",
+	"X509_CERT",
+	"UNKNOWN",
+};
+
+static const char *const audit_hook_names[__IPE_HOOK_MAX] = {
+	"BPRM_CHECK",
+	"BPRM_CREDS_FOR_EXEC",
+	"MMAP",
+	"MPROTECT",
+	"KERNEL_READ",
+	"KERNEL_LOAD",
+};
+
+static const char *const audit_prop_names[__IPE_PROP_MAX] = {
+	"boot_verified=FALSE",
+	"boot_verified=TRUE",
+	"dmverity_roothash=",
+	"dmverity_signature=FALSE",
+	"dmverity_signature=TRUE",
+	"fsverity_digest=",
+	"fsverity_signature=FALSE",
+	"fsverity_signature=TRUE",
+};
+
+/**
+ * audit_dmv_roothash() - audit the roothash of a dmverity_roothash property.
+ * @ab: Supplies a pointer to the audit_buffer to append to.
+ * @rh: Supplies a pointer to the digest structure.
+ */
+static void audit_dmv_roothash(struct audit_buffer *ab, const void *rh)
+{
+	audit_log_format(ab, "%s", audit_prop_names[IPE_PROP_DMV_ROOTHASH]);
+	ipe_digest_audit(ab, rh);
+}
+
+/**
+ * audit_fsv_digest() - audit the digest of a fsverity_digest property.
+ * @ab: Supplies a pointer to the audit_buffer to append to.
+ * @d: Supplies a pointer to the digest structure.
+ */
+static void audit_fsv_digest(struct audit_buffer *ab, const void *d)
+{
+	audit_log_format(ab, "%s", audit_prop_names[IPE_PROP_FSV_DIGEST]);
+	ipe_digest_audit(ab, d);
+}
+
+/**
+ * audit_rule() - audit an IPE policy rule.
+ * @ab: Supplies a pointer to the audit_buffer to append to.
+ * @r: Supplies a pointer to the ipe_rule to approximate a string form for.
+ */
+static void audit_rule(struct audit_buffer *ab, const struct ipe_rule *r)
+{
+	const struct ipe_prop *ptr;
+
+	audit_log_format(ab, " rule=\"op=%s ", audit_op_names[r->op]);
+
+	list_for_each_entry(ptr, &r->props, next) {
+		switch (ptr->type) {
+		case IPE_PROP_DMV_ROOTHASH:
+			audit_dmv_roothash(ab, ptr->value);
+			break;
+		case IPE_PROP_FSV_DIGEST:
+			audit_fsv_digest(ab, ptr->value);
+			break;
+		default:
+			audit_log_format(ab, "%s", audit_prop_names[ptr->type]);
+			break;
+		}
+
+		audit_log_format(ab, " ");
+	}
+
+	audit_log_format(ab, "action=%s\"", ACTSTR(r->action));
+}
+
+/**
+ * ipe_audit_match() - Audit a rule match in a policy evaluation.
+ * @ctx: Supplies a pointer to the evaluation context that was used in the
+ *	 evaluation.
+ * @match_type: Supplies the scope of the match: rule, operation default,
+ *		global default.
+ * @act: Supplies the IPE's evaluation decision, deny or allow.
+ * @r: Supplies a pointer to the rule that was matched, if possible.
+ */
+void ipe_audit_match(const struct ipe_eval_ctx *const ctx,
+		     enum ipe_match match_type,
+		     enum ipe_action_type act, const struct ipe_rule *const r)
+{
+	const char *op = audit_op_names[ctx->op];
+	char comm[sizeof(current->comm)];
+	struct audit_buffer *ab;
+	struct inode *inode;
+
+	if (act != IPE_ACTION_DENY && !READ_ONCE(success_audit))
+		return;
+
+	ab = audit_log_start(audit_context(), GFP_ATOMIC | __GFP_NOWARN,
+			     AUDIT_IPE_ACCESS);
+	if (!ab)
+		return;
+
+	audit_log_format(ab, "ipe_op=%s ipe_hook=%s enforcing=%d pid=%d comm=",
+			 op, audit_hook_names[ctx->hook], READ_ONCE(enforce),
+			 task_tgid_nr(current));
+	audit_log_untrustedstring(ab, get_task_comm(comm, current));
+
+	if (ctx->file) {
+		audit_log_d_path(ab, " path=", &ctx->file->f_path);
+		inode = file_inode(ctx->file);
+		if (inode) {
+			audit_log_format(ab, " dev=");
+			audit_log_untrustedstring(ab, inode->i_sb->s_id);
+			audit_log_format(ab, " ino=%llu", inode->i_ino);
+		} else {
+			audit_log_format(ab, " dev=? ino=?");
+		}
+	} else {
+		audit_log_format(ab, " path=? dev=? ino=?");
+	}
+
+	if (match_type == IPE_MATCH_RULE)
+		audit_rule(ab, r);
+	else if (match_type == IPE_MATCH_TABLE)
+		audit_log_format(ab, " rule=\"DEFAULT op=%s action=%s\"", op,
+				 ACTSTR(act));
+	else
+		audit_log_format(ab, " rule=\"DEFAULT action=%s\"",
+				 ACTSTR(act));
+
+	audit_log_end(ab);
+}
+
+/**
+ * audit_policy() - Audit a policy's name, version and thumbprint to @ab.
+ * @ab: Supplies a pointer to the audit buffer to append to.
+ * @audit_format: Supplies a pointer to the audit format string
+ * @p: Supplies a pointer to the policy to audit.
+ */
+static void audit_policy(struct audit_buffer *ab,
+			 const char *audit_format,
+			 const struct ipe_policy *const p)
+{
+	u8 digest[SHA256_DIGEST_SIZE];
+
+	sha256(p->pkcs7, p->pkcs7len, digest);
+
+	audit_log_format(ab, audit_format, p->parsed->name,
+			 p->parsed->version.major, p->parsed->version.minor,
+			 p->parsed->version.rev);
+	audit_log_n_hex(ab, digest, sizeof(digest));
+}
+
+/**
+ * ipe_audit_policy_activation() - Audit a policy being activated.
+ * @op: Supplies a pointer to the previously activated policy to audit.
+ * @np: Supplies a pointer to the newly activated policy to audit.
+ */
+void ipe_audit_policy_activation(const struct ipe_policy *const op,
+				 const struct ipe_policy *const np)
+{
+	struct audit_buffer *ab;
+
+	ab = audit_log_start(audit_context(), GFP_KERNEL,
+			     AUDIT_IPE_CONFIG_CHANGE);
+	if (!ab)
+		return;
+
+	if (op) {
+		audit_policy(ab, AUDIT_OLD_ACTIVE_POLICY_FMT, op);
+		audit_log_format(ab, " ");
+	} else {
+		/*
+		 * old active policy can be NULL if there is no kernel
+		 * built-in policy
+		 */
+		audit_log_format(ab, AUDIT_OLD_ACTIVE_POLICY_NULL_FMT);
+		audit_log_format(ab, " ");
+	}
+	audit_policy(ab, AUDIT_NEW_ACTIVE_POLICY_FMT, np);
+	audit_log_format(ab, " auid=%u ses=%u lsm=ipe res=1",
+			 from_kuid(&init_user_ns, audit_get_loginuid(current)),
+			 audit_get_sessionid(current));
+
+	audit_log_end(ab);
+}
+
+/**
+ * ipe_audit_policy_load() - Audit a policy loading event.
+ * @p: Supplies a pointer to the policy to audit or an error pointer.
+ */
+void ipe_audit_policy_load(const struct ipe_policy *const p)
+{
+	struct audit_buffer *ab;
+	int err = 0;
+
+	ab = audit_log_start(audit_context(), GFP_KERNEL,
+			     AUDIT_IPE_POLICY_LOAD);
+	if (!ab)
+		return;
+
+	if (!IS_ERR(p)) {
+		audit_policy(ab, AUDIT_POLICY_LOAD_FMT, p);
+	} else {
+		audit_log_format(ab, AUDIT_POLICY_LOAD_NULL_FMT);
+		err = PTR_ERR(p);
+	}
+
+	audit_log_format(ab, " auid=%u ses=%u lsm=ipe res=%d errno=%d",
+			 from_kuid(&init_user_ns, audit_get_loginuid(current)),
+			 audit_get_sessionid(current), !err, err);
+
+	audit_log_end(ab);
+}
+
+/**
+ * ipe_audit_enforce() - Audit a change in IPE's enforcement state.
+ * @new_enforce: The new value enforce to be set.
+ * @old_enforce: The old value currently in enforce.
+ */
+void ipe_audit_enforce(bool new_enforce, bool old_enforce)
+{
+	struct audit_buffer *ab;
+
+	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS);
+	if (!ab)
+		return;
+
+	audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS,
+		  "enforcing=%d old_enforcing=%d auid=%u ses=%u"
+		  " enabled=1 old-enabled=1 lsm=ipe res=1",
+		  new_enforce, old_enforce,
+		  from_kuid(&init_user_ns, audit_get_loginuid(current)),
+		  audit_get_sessionid(current));
+
+	audit_log_end(ab);
+}