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-rw-r--r--security/apparmor/apparmorfs.c4
-rw-r--r--security/apparmor/domain.c13
-rw-r--r--security/apparmor/include/match.h9
-rw-r--r--security/apparmor/match.c43
4 files changed, 62 insertions, 7 deletions
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index be6dc548d307..d7a179cdaa1e 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -591,7 +591,7 @@ static __poll_t ns_revision_poll(struct file *file, poll_table *pt)
void __aa_bump_ns_revision(struct aa_ns *ns)
{
- WRITE_ONCE(ns->revision, ns->revision + 1);
+ WRITE_ONCE(ns->revision, READ_ONCE(ns->revision) + 1);
wake_up_interruptible(&ns->wait);
}
@@ -2331,6 +2331,8 @@ static struct aa_sfs_entry aa_sfs_entry_versions[] = {
static struct aa_sfs_entry aa_sfs_entry_policy[] = {
AA_SFS_DIR("versions", aa_sfs_entry_versions),
AA_SFS_FILE_BOOLEAN("set_load", 1),
+ /* number of out of band transitions supported */
+ AA_SFS_FILE_U64("outofband", MAX_OOB_SUPPORTED),
{ }
};
diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index f73ba303ba24..0a91d5f7d0e9 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -320,8 +320,7 @@ static int aa_xattrs_match(const struct linux_binprm *bprm,
might_sleep();
/* transition from exec match to xattr set */
- state = aa_dfa_null_transition(profile->xmatch, state);
-
+ state = aa_dfa_outofband_transition(profile->xmatch, state);
d = bprm->file->f_path.dentry;
for (i = 0; i < profile->xattr_count; i++) {
@@ -330,7 +329,13 @@ static int aa_xattrs_match(const struct linux_binprm *bprm,
if (size >= 0) {
u32 perm;
- /* Check the xattr value, not just presence */
+ /*
+ * Check the xattr presence before value. This ensure
+ * that not present xattr can be distinguished from a 0
+ * length value or rule that matches any value
+ */
+ state = aa_dfa_null_transition(profile->xmatch, state);
+ /* Check xattr value */
state = aa_dfa_match_len(profile->xmatch, state, value,
size);
perm = dfa_user_allow(profile->xmatch, state);
@@ -340,7 +345,7 @@ static int aa_xattrs_match(const struct linux_binprm *bprm,
}
}
/* transition to next element */
- state = aa_dfa_null_transition(profile->xmatch, state);
+ state = aa_dfa_outofband_transition(profile->xmatch, state);
if (size < 0) {
/*
* No xattr match, so verify if transition to
diff --git a/security/apparmor/include/match.h b/security/apparmor/include/match.h
index f280b046361e..884489590588 100644
--- a/security/apparmor/include/match.h
+++ b/security/apparmor/include/match.h
@@ -37,6 +37,10 @@
#define YYTH_MAGIC 0x1B5E783D
#define YYTH_FLAG_DIFF_ENCODE 1
+#define YYTH_FLAG_OOB_TRANS 2
+#define YYTH_FLAGS (YYTH_FLAG_DIFF_ENCODE | YYTH_FLAG_OOB_TRANS)
+
+#define MAX_OOB_SUPPORTED 1
struct table_set_header {
u32 th_magic; /* YYTH_MAGIC */
@@ -94,6 +98,7 @@ struct table_header {
struct aa_dfa {
struct kref count;
u16 flags;
+ u32 max_oob;
struct table_header *tables[YYTD_ID_TSIZE];
};
@@ -127,6 +132,8 @@ unsigned int aa_dfa_match(struct aa_dfa *dfa, unsigned int start,
const char *str);
unsigned int aa_dfa_next(struct aa_dfa *dfa, unsigned int state,
const char c);
+unsigned int aa_dfa_outofband_transition(struct aa_dfa *dfa,
+ unsigned int state);
unsigned int aa_dfa_match_until(struct aa_dfa *dfa, unsigned int start,
const char *str, const char **retpos);
unsigned int aa_dfa_matchn_until(struct aa_dfa *dfa, unsigned int start,
@@ -183,7 +190,7 @@ static inline void aa_put_dfa(struct aa_dfa *dfa)
#define MARK_DIFF_ENCODE 0x40000000
#define MATCH_FLAG_OOB_TRANSITION 0x20000000
#define MATCH_FLAGS_MASK 0xff000000
-#define MATCH_FLAGS_VALID MATCH_FLAG_DIFF_ENCODE
+#define MATCH_FLAGS_VALID (MATCH_FLAG_DIFF_ENCODE | MATCH_FLAG_OOB_TRANSITION)
#define MATCH_FLAGS_INVALID (MATCH_FLAGS_MASK & ~MATCH_FLAGS_VALID)
#endif /* __AA_MATCH_H */
diff --git a/security/apparmor/match.c b/security/apparmor/match.c
index 651dbb6e38b8..e605b7d53fb4 100644
--- a/security/apparmor/match.c
+++ b/security/apparmor/match.c
@@ -212,6 +212,16 @@ static int verify_dfa(struct aa_dfa *dfa)
goto out;
}
}
+ if ((BASE_TABLE(dfa)[i] & MATCH_FLAG_OOB_TRANSITION)) {
+ if (base_idx(BASE_TABLE(dfa)[i]) < dfa->max_oob) {
+ pr_err("AppArmor DFA out of bad transition out of range");
+ goto out;
+ }
+ if (!(dfa->flags & YYTH_FLAG_OOB_TRANS)) {
+ pr_err("AppArmor DFA out of bad transition state without header flag");
+ goto out;
+ }
+ }
if (base_idx(BASE_TABLE(dfa)[i]) + 255 >= trans_count) {
pr_err("AppArmor DFA next/check upper bounds error\n");
goto out;
@@ -314,9 +324,23 @@ struct aa_dfa *aa_dfa_unpack(void *blob, size_t size, int flags)
goto fail;
dfa->flags = ntohs(*(__be16 *) (data + 12));
- if (dfa->flags != 0 && dfa->flags != YYTH_FLAG_DIFF_ENCODE)
+ if (dfa->flags & ~(YYTH_FLAGS))
goto fail;
+ /*
+ * TODO: needed for dfa to support more than 1 oob
+ * if (dfa->flags & YYTH_FLAGS_OOB_TRANS) {
+ * if (hsize < 16 + 4)
+ * goto fail;
+ * dfa->max_oob = ntol(*(__be32 *) (data + 16));
+ * if (dfa->max <= MAX_OOB_SUPPORTED) {
+ * pr_err("AppArmor DFA OOB greater than supported\n");
+ * goto fail;
+ * }
+ * }
+ */
+ dfa->max_oob = 1;
+
data += hsize;
size -= hsize;
@@ -505,6 +529,23 @@ unsigned int aa_dfa_next(struct aa_dfa *dfa, unsigned int state,
return state;
}
+unsigned int aa_dfa_outofband_transition(struct aa_dfa *dfa, unsigned int state)
+{
+ u16 *def = DEFAULT_TABLE(dfa);
+ u32 *base = BASE_TABLE(dfa);
+ u16 *next = NEXT_TABLE(dfa);
+ u16 *check = CHECK_TABLE(dfa);
+ u32 b = (base)[(state)];
+
+ if (!(b & MATCH_FLAG_OOB_TRANSITION))
+ return DFA_NOMATCH;
+
+ /* No Equivalence class remapping for outofband transitions */
+ match_char(state, def, base, next, check, -1);
+
+ return state;
+}
+
/**
* aa_dfa_match_until - traverse @dfa until accept state or end of input
* @dfa: the dfa to match @str against (NOT NULL)