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| author | Casey Schaufler <casey@schaufler-ca.com> | 2012-06-18 19:01:36 -0700 |
|---|---|---|
| committer | Casey Schaufler <casey@schaufler-ca.com> | 2012-07-13 15:49:24 -0700 |
| commit | 3518721a8932b2a243f415c374aef020380efc9d (patch) | |
| tree | f16a039687aaf395e6751b7a9edda85e83b52502 /security | |
| parent | 1880eff77e7a7cb46c68fae7cfa33f72f0a6e70e (diff) | |
| download | lwn-3518721a8932b2a243f415c374aef020380efc9d.tar.gz lwn-3518721a8932b2a243f415c374aef020380efc9d.zip | |
Smack: user access check bounds
Some of the bounds checking used on the /smack/access
interface was lost when support for long labels was
added. No kernel access checks are affected, however
this is a case where /smack/access could be used
incorrectly and fail to detect the error. This patch
reintroduces the original checks.
Targeted for git://git.gitorious.org/smack-next/kernel.git
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Diffstat (limited to 'security')
| -rw-r--r-- | security/smack/smackfs.c | 26 |
1 files changed, 12 insertions, 14 deletions
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index 21529658662b..29b760d6b746 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -215,28 +215,27 @@ static int smk_set_access(struct smack_rule *srp, struct list_head *rule_list, * @access: access string * @rule: Smack rule * @import: if non-zero, import labels + * @len: label length limit * * Returns 0 on success, -1 on failure */ static int smk_fill_rule(const char *subject, const char *object, const char *access, struct smack_rule *rule, - int import) + int import, int len) { - int rc = -1; - int done; const char *cp; struct smack_known *skp; if (import) { - rule->smk_subject = smk_import(subject, 0); + rule->smk_subject = smk_import(subject, len); if (rule->smk_subject == NULL) return -1; - rule->smk_object = smk_import(object, 0); + rule->smk_object = smk_import(object, len); if (rule->smk_object == NULL) return -1; } else { - cp = smk_parse_smack(subject, 0); + cp = smk_parse_smack(subject, len); if (cp == NULL) return -1; skp = smk_find_entry(cp); @@ -245,7 +244,7 @@ static int smk_fill_rule(const char *subject, const char *object, return -1; rule->smk_subject = skp->smk_known; - cp = smk_parse_smack(object, 0); + cp = smk_parse_smack(object, len); if (cp == NULL) return -1; skp = smk_find_entry(cp); @@ -257,7 +256,7 @@ static int smk_fill_rule(const char *subject, const char *object, rule->smk_access = 0; - for (cp = access, done = 0; *cp && !done; cp++) { + for (cp = access; *cp != '\0'; cp++) { switch (*cp) { case '-': break; @@ -282,13 +281,11 @@ static int smk_fill_rule(const char *subject, const char *object, rule->smk_access |= MAY_TRANSMUTE; break; default: - done = 1; - break; + return 0; } } - rc = 0; - return rc; + return 0; } /** @@ -304,7 +301,8 @@ static int smk_parse_rule(const char *data, struct smack_rule *rule, int import) int rc; rc = smk_fill_rule(data, data + SMK_LABELLEN, - data + SMK_LABELLEN + SMK_LABELLEN, rule, import); + data + SMK_LABELLEN + SMK_LABELLEN, rule, import, + SMK_LABELLEN); return rc; } @@ -340,7 +338,7 @@ static int smk_parse_long_rule(const char *data, struct smack_rule *rule, goto free_out_o; if (sscanf(data, "%s %s %s", subject, object, access) == 3) - rc = smk_fill_rule(subject, object, access, rule, import); + rc = smk_fill_rule(subject, object, access, rule, import, 0); kfree(access); free_out_o: |