From: John Johansen Date: Wed, 22 Aug 2018 00:19:53 +0000 (-0700) Subject: apparmor: remove no-op permission check in policy_unpack X-Git-Tag: v4.19~293^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c037bd615885f1d9d3bdb48531bace79fae1505d;p=platform%2Fkernel%2Flinux-rpi.git apparmor: remove no-op permission check in policy_unpack The patch 736ec752d95e: "AppArmor: policy routines for loading and unpacking policy" from Jul 29, 2010, leads to the following static checker warning: security/apparmor/policy_unpack.c:410 verify_accept() warn: bitwise AND condition is false here security/apparmor/policy_unpack.c:413 verify_accept() warn: bitwise AND condition is false here security/apparmor/policy_unpack.c 392 #define DFA_VALID_PERM_MASK 0xffffffff 393 #define DFA_VALID_PERM2_MASK 0xffffffff 394 395 /** 396 * verify_accept - verify the accept tables of a dfa 397 * @dfa: dfa to verify accept tables of (NOT NULL) 398 * @flags: flags governing dfa 399 * 400 * Returns: 1 if valid accept tables else 0 if error 401 */ 402 static bool verify_accept(struct aa_dfa *dfa, int flags) 403 { 404 int i; 405 406 /* verify accept permissions */ 407 for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) { 408 int mode = ACCEPT_TABLE(dfa)[i]; 409 410 if (mode & ~DFA_VALID_PERM_MASK) 411 return 0; 412 413 if (ACCEPT_TABLE2(dfa)[i] & ~DFA_VALID_PERM2_MASK) 414 return 0; fixes: 736ec752d95e ("AppArmor: policy routines for loading and unpacking policy") Reported-by: Dan Carpenter Signed-off-by: John Johansen --- diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c index 0e566a0..21cb384 100644 --- a/security/apparmor/policy_unpack.c +++ b/security/apparmor/policy_unpack.c @@ -389,32 +389,6 @@ static int unpack_strdup(struct aa_ext *e, char **string, const char *name) return res; } -#define DFA_VALID_PERM_MASK 0xffffffff -#define DFA_VALID_PERM2_MASK 0xffffffff - -/** - * verify_accept - verify the accept tables of a dfa - * @dfa: dfa to verify accept tables of (NOT NULL) - * @flags: flags governing dfa - * - * Returns: 1 if valid accept tables else 0 if error - */ -static bool verify_accept(struct aa_dfa *dfa, int flags) -{ - int i; - - /* verify accept permissions */ - for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) { - int mode = ACCEPT_TABLE(dfa)[i]; - - if (mode & ~DFA_VALID_PERM_MASK) - return 0; - - if (ACCEPT_TABLE2(dfa)[i] & ~DFA_VALID_PERM2_MASK) - return 0; - } - return 1; -} /** * unpack_dfa - unpack a file rule dfa @@ -445,15 +419,9 @@ static struct aa_dfa *unpack_dfa(struct aa_ext *e) if (IS_ERR(dfa)) return dfa; - if (!verify_accept(dfa, flags)) - goto fail; } return dfa; - -fail: - aa_put_dfa(dfa); - return ERR_PTR(-EPROTO); } /**