Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 326 insertions, 0 deletions

diff --git a/security/apparmor/policy_compat.c b/security/apparmor/policy_compat.c
new file mode 100644
index 0000000000..0cb02da8a3
--- /dev/null
+++ b/security/apparmor/policy_compat.c
@@ -0,0 +1,326 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor functions for unpacking policy loaded
+ * from userspace.
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2022 Canonical Ltd.
+ *
+ * Code to provide backwards compatibility with older policy versions,
+ * by converting/mapping older policy formats into the newer internal
+ * formats.
+ */
+
+#include <linux/ctype.h>
+#include <linux/errno.h>
+
+#include "include/lib.h"
+#include "include/policy_unpack.h"
+#include "include/policy_compat.h"
+
+/* remap old accept table embedded permissions to separate permission table */
+static u32 dfa_map_xindex(u16 mask)
+{
+	u16 old_index = (mask >> 10) & 0xf;
+	u32 index = 0;
+
+	if (mask & 0x100)
+		index |= AA_X_UNSAFE;
+	if (mask & 0x200)
+		index |= AA_X_INHERIT;
+	if (mask & 0x80)
+		index |= AA_X_UNCONFINED;
+
+	if (old_index == 1) {
+		index |= AA_X_UNCONFINED;
+	} else if (old_index == 2) {
+		index |= AA_X_NAME;
+	} else if (old_index == 3) {
+		index |= AA_X_NAME | AA_X_CHILD;
+	} else if (old_index) {
+		index |= AA_X_TABLE;
+		index |= old_index - 4;
+	}
+
+	return index;
+}
+
+/*
+ * map old dfa inline permissions to new format
+ */
+#define dfa_user_allow(dfa, state) (((ACCEPT_TABLE(dfa)[state]) & 0x7f) | \
+				    ((ACCEPT_TABLE(dfa)[state]) & 0x80000000))
+#define dfa_user_xbits(dfa, state) (((ACCEPT_TABLE(dfa)[state]) >> 7) & 0x7f)
+#define dfa_user_audit(dfa, state) ((ACCEPT_TABLE2(dfa)[state]) & 0x7f)
+#define dfa_user_quiet(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 7) & 0x7f)
+#define dfa_user_xindex(dfa, state) \
+	(dfa_map_xindex(ACCEPT_TABLE(dfa)[state] & 0x3fff))
+
+#define dfa_other_allow(dfa, state) ((((ACCEPT_TABLE(dfa)[state]) >> 14) & \
+				      0x7f) |				\
+				     ((ACCEPT_TABLE(dfa)[state]) & 0x80000000))
+#define dfa_other_xbits(dfa, state) \
+	((((ACCEPT_TABLE(dfa)[state]) >> 7) >> 14) & 0x7f)
+#define dfa_other_audit(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 14) & 0x7f)
+#define dfa_other_quiet(dfa, state) \
+	((((ACCEPT_TABLE2(dfa)[state]) >> 7) >> 14) & 0x7f)
+#define dfa_other_xindex(dfa, state) \
+	dfa_map_xindex((ACCEPT_TABLE(dfa)[state] >> 14) & 0x3fff)
+
+/**
+ * map_old_perms - map old file perms layout to the new layout
+ * @old: permission set in old mapping
+ *
+ * Returns: new permission mapping
+ */
+static u32 map_old_perms(u32 old)
+{
+	u32 new = old & 0xf;
+
+	if (old & MAY_READ)
+		new |= AA_MAY_GETATTR | AA_MAY_OPEN;
+	if (old & MAY_WRITE)
+		new |= AA_MAY_SETATTR | AA_MAY_CREATE | AA_MAY_DELETE |
+		       AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_OPEN;
+	if (old & 0x10)
+		new |= AA_MAY_LINK;
+	/* the old mapping lock and link_subset flags where overlaid
+	 * and use was determined by part of a pair that they were in
+	 */
+	if (old & 0x20)
+		new |= AA_MAY_LOCK | AA_LINK_SUBSET;
+	if (old & 0x40)	/* AA_EXEC_MMAP */
+		new |= AA_EXEC_MMAP;
+
+	return new;
+}
+
+static void compute_fperms_allow(struct aa_perms *perms, struct aa_dfa *dfa,
+				 aa_state_t state)
+{
+	perms->allow |= AA_MAY_GETATTR;
+
+	/* change_profile wasn't determined by ownership in old mapping */
+	if (ACCEPT_TABLE(dfa)[state] & 0x80000000)
+		perms->allow |= AA_MAY_CHANGE_PROFILE;
+	if (ACCEPT_TABLE(dfa)[state] & 0x40000000)
+		perms->allow |= AA_MAY_ONEXEC;
+}
+
+static struct aa_perms compute_fperms_user(struct aa_dfa *dfa,
+					   aa_state_t state)
+{
+	struct aa_perms perms = { };
+
+	perms.allow = map_old_perms(dfa_user_allow(dfa, state));
+	perms.audit = map_old_perms(dfa_user_audit(dfa, state));
+	perms.quiet = map_old_perms(dfa_user_quiet(dfa, state));
+	perms.xindex = dfa_user_xindex(dfa, state);
+
+	compute_fperms_allow(&perms, dfa, state);
+
+	return perms;
+}
+
+static struct aa_perms compute_fperms_other(struct aa_dfa *dfa,
+					    aa_state_t state)
+{
+	struct aa_perms perms = { };
+
+	perms.allow = map_old_perms(dfa_other_allow(dfa, state));
+	perms.audit = map_old_perms(dfa_other_audit(dfa, state));
+	perms.quiet = map_old_perms(dfa_other_quiet(dfa, state));
+	perms.xindex = dfa_other_xindex(dfa, state);
+
+	compute_fperms_allow(&perms, dfa, state);
+
+	return perms;
+}
+
+/**
+ * compute_fperms - convert dfa compressed perms to internal perms and store
+ *		    them so they can be retrieved later.
+ * @dfa: a dfa using fperms to remap to internal permissions
+ *
+ * Returns: remapped perm table
+ */
+static struct aa_perms *compute_fperms(struct aa_dfa *dfa,
+				       u32 *size)
+{
+	aa_state_t state;
+	unsigned int state_count;
+	struct aa_perms *table;
+
+	AA_BUG(!dfa);
+
+	state_count = dfa->tables[YYTD_ID_BASE]->td_lolen;
+	/* DFAs are restricted from having a state_count of less than 2 */
+	table = kvcalloc(state_count * 2, sizeof(struct aa_perms), GFP_KERNEL);
+	if (!table)
+		return NULL;
+	*size = state_count * 2;
+
+	for (state = 0; state < state_count; state++) {
+		table[state * 2] = compute_fperms_user(dfa, state);
+		table[state * 2 + 1] = compute_fperms_other(dfa, state);
+	}
+
+	return table;
+}
+
+static struct aa_perms *compute_xmatch_perms(struct aa_dfa *xmatch,
+				      u32 *size)
+{
+	struct aa_perms *perms;
+	int state;
+	int state_count;
+
+	AA_BUG(!xmatch);
+
+	state_count = xmatch->tables[YYTD_ID_BASE]->td_lolen;
+	/* DFAs are restricted from having a state_count of less than 2 */
+	perms = kvcalloc(state_count, sizeof(struct aa_perms), GFP_KERNEL);
+	if (!perms)
+		return NULL;
+	*size = state_count;
+
+	/* zero init so skip the trap state (state == 0) */
+	for (state = 1; state < state_count; state++)
+		perms[state].allow = dfa_user_allow(xmatch, state);
+
+	return perms;
+}
+
+static u32 map_other(u32 x)
+{
+	return ((x & 0x3) << 8) |	/* SETATTR/GETATTR */
+		((x & 0x1c) << 18) |	/* ACCEPT/BIND/LISTEN */
+		((x & 0x60) << 19);	/* SETOPT/GETOPT */
+}
+
+static u32 map_xbits(u32 x)
+{
+	return ((x & 0x1) << 7) |
+		((x & 0x7e) << 9);
+}
+
+static struct aa_perms compute_perms_entry(struct aa_dfa *dfa,
+					   aa_state_t state,
+					   u32 version)
+{
+	struct aa_perms perms = { };
+
+	perms.allow = dfa_user_allow(dfa, state);
+	perms.audit = dfa_user_audit(dfa, state);
+	perms.quiet = dfa_user_quiet(dfa, state);
+
+	/*
+	 * This mapping is convulated due to history.
+	 * v1-v4: only file perms, which are handled by compute_fperms
+	 * v5: added policydb which dropped user conditional to gain new
+	 *     perm bits, but had to map around the xbits because the
+	 *     userspace compiler was still munging them.
+	 * v9: adds using the xbits in policydb because the compiler now
+	 *     supports treating policydb permission bits different.
+	 *     Unfortunately there is no way to force auditing on the
+	 *     perms represented by the xbits
+	 */
+	perms.allow |= map_other(dfa_other_allow(dfa, state));
+	if (VERSION_LE(version, v8))
+		perms.allow |= AA_MAY_LOCK;
+	else
+		perms.allow |= map_xbits(dfa_user_xbits(dfa, state));
+
+	/*
+	 * for v5-v9 perm mapping in the policydb, the other set is used
+	 * to extend the general perm set
+	 */
+	perms.audit |= map_other(dfa_other_audit(dfa, state));
+	perms.quiet |= map_other(dfa_other_quiet(dfa, state));
+	if (VERSION_GT(version, v8))
+		perms.quiet |= map_xbits(dfa_other_xbits(dfa, state));
+
+	return perms;
+}
+
+static struct aa_perms *compute_perms(struct aa_dfa *dfa, u32 version,
+				      u32 *size)
+{
+	unsigned int state;
+	unsigned int state_count;
+	struct aa_perms *table;
+
+	AA_BUG(!dfa);
+
+	state_count = dfa->tables[YYTD_ID_BASE]->td_lolen;
+	/* DFAs are restricted from having a state_count of less than 2 */
+	table = kvcalloc(state_count, sizeof(struct aa_perms), GFP_KERNEL);
+	if (!table)
+		return NULL;
+	*size = state_count;
+
+	/* zero init so skip the trap state (state == 0) */
+	for (state = 1; state < state_count; state++)
+		table[state] = compute_perms_entry(dfa, state, version);
+
+	return table;
+}
+
+/**
+ * remap_dfa_accept - remap old dfa accept table to be an index
+ * @dfa: dfa to do the remapping on
+ * @factor: scaling factor for the index conversion.
+ *
+ * Used in conjunction with compute_Xperms, it converts old style perms
+ * that are encoded in the dfa accept tables to the new style where
+ * there is a permission table and the accept table is an index into
+ * the permission table.
+ */
+static void remap_dfa_accept(struct aa_dfa *dfa, unsigned int factor)
+{
+	unsigned int state;
+	unsigned int state_count = dfa->tables[YYTD_ID_BASE]->td_lolen;
+
+	AA_BUG(!dfa);
+
+	for (state = 0; state < state_count; state++)
+		ACCEPT_TABLE(dfa)[state] = state * factor;
+	kvfree(dfa->tables[YYTD_ID_ACCEPT2]);
+	dfa->tables[YYTD_ID_ACCEPT2] = NULL;
+}
+
+/* TODO: merge different dfa mappings into single map_policy fn */
+int aa_compat_map_xmatch(struct aa_policydb *policy)
+{
+	policy->perms = compute_xmatch_perms(policy->dfa, &policy->size);
+	if (!policy->perms)
+		return -ENOMEM;
+
+	remap_dfa_accept(policy->dfa, 1);
+
+	return 0;
+}
+
+int aa_compat_map_policy(struct aa_policydb *policy, u32 version)
+{
+	policy->perms = compute_perms(policy->dfa, version, &policy->size);
+	if (!policy->perms)
+		return -ENOMEM;
+
+	remap_dfa_accept(policy->dfa, 1);
+
+	return 0;
+}
+
+int aa_compat_map_file(struct aa_policydb *policy)
+{
+	policy->perms = compute_fperms(policy->dfa, &policy->size);
+	if (!policy->perms)
+		return -ENOMEM;
+
+	remap_dfa_accept(policy->dfa, 2);
+
+	return 0;
+}