apparmor: use the dfa to do label parse string splitting

The current split scheme is actually wrong in that it splits
  ///&

where that is invalid and should fail. Use the dfa to do a proper
bounded split without having to worry about getting the string
processing right in code.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
This commit is contained in:
John Johansen
2017-09-06 14:57:59 -07:00
parent cf65fabc2a
commit 6e0654d20e
5 changed files with 170 additions and 11 deletions

View File

@@ -330,6 +330,31 @@ void aa_label_printk(struct aa_label *label, gfp_t gfp);
struct aa_label *aa_label_parse(struct aa_label *base, const char *str,
gfp_t gfp, bool create, bool force_stack);
static inline const char *aa_label_strn_split(const char *str, int n)
{
const char *pos;
unsigned int state;
state = aa_dfa_matchn_until(stacksplitdfa, DFA_START, str, n, &pos);
if (!ACCEPT_TABLE(stacksplitdfa)[state])
return NULL;
return pos - 3;
}
static inline const char *aa_label_str_split(const char *str)
{
const char *pos;
unsigned int state;
state = aa_dfa_match_until(stacksplitdfa, DFA_START, str, &pos);
if (!ACCEPT_TABLE(stacksplitdfa)[state])
return NULL;
return pos - 3;
}
struct aa_perms;
int aa_label_match(struct aa_profile *profile, struct aa_label *label,