[PATCH AUTOSEL 4.9 06/48] Smack: Fix wrong semantics in smk_access_entry()

[PATCH AUTOSEL 4.9 06/48] Smack: Fix wrong semantics in smk_access_entry()

[Sasha Levin]

From: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>

[ Upstream commit 6d14f5c7028eea70760df284057fe198ce7778dd ]

In the smk_access_entry() function, if no matching rule is found
in the rust_list, a negative error code will be used to perform bit
operations with the MAY_ enumeration value. This is semantically
wrong. This patch fixes this issue.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 security/smack/smack_access.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index e5d5c7fb2dac..b25cc69ef7ba 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -90,23 +90,22 @@ int log_policy = SMACK_AUDIT_DENIED;
 int smk_access_entry(char *subject_label, char *object_label,
 			struct list_head *rule_list)
 {
-	int may = -ENOENT;
 	struct smack_rule *srp;
 
 	list_for_each_entry_rcu(srp, rule_list, list) {
 		if (srp->smk_object->smk_known == object_label &&
 		    srp->smk_subject->smk_known == subject_label) {
-			may = srp->smk_access;
-			break;
+			int may = srp->smk_access;
+			/*
+			 * MAY_WRITE implies MAY_LOCK.
+			 */
+			if ((may & MAY_WRITE) == MAY_WRITE)
+				may |= MAY_LOCK;
+			return may;
 		}
 	}
 
-	/*
-	 * MAY_WRITE implies MAY_LOCK.
-	 */
-	if ((may & MAY_WRITE) == MAY_WRITE)
-		may |= MAY_LOCK;
-	return may;
+	return -ENOENT;
 }
 
 /**
-- 
2.30.2

[PATCH AUTOSEL 4.9 47/48] net: fix NULL pointer reference in cipso_v4_doi_free

[Sasha Levin]

From: 王贇 <yun.wang@linux.alibaba.com>

[ Upstream commit 733c99ee8be9a1410287cdbb943887365e83b2d6 ]

In netlbl_cipsov4_add_std() when 'doi_def->map.std' alloc
failed, we sometime observe panic:

  BUG: kernel NULL pointer dereference, address:
  ...
  RIP: 0010:cipso_v4_doi_free+0x3a/0x80
  ...
  Call Trace:
   netlbl_cipsov4_add_std+0xf4/0x8c0
   netlbl_cipsov4_add+0x13f/0x1b0
   genl_family_rcv_msg_doit.isra.15+0x132/0x170
   genl_rcv_msg+0x125/0x240

This is because in cipso_v4_doi_free() there is no check
on 'doi_def->map.std' when 'doi_def->type' equal 1, which
is possibe, since netlbl_cipsov4_add_std() haven't initialize
it before alloc 'doi_def->map.std'.

This patch just add the check to prevent panic happen for similar
cases.

Reported-by: Abaci <abaci@linux.alibaba.com>
Signed-off-by: Michael Wang <yun.wang@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netlabel/netlabel_cipso_v4.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netlabel/netlabel_cipso_v4.c b/net/netlabel/netlabel_cipso_v4.c
index 7fd1104ba900..d17a8f3d3387 100644
--- a/net/netlabel/netlabel_cipso_v4.c
+++ b/net/netlabel/netlabel_cipso_v4.c
@@ -163,8 +163,8 @@ static int netlbl_cipsov4_add_std(struct genl_info *info,
 		return -ENOMEM;
 	doi_def->map.std = kzalloc(sizeof(*doi_def->map.std), GFP_KERNEL);
 	if (doi_def->map.std == NULL) {
-		ret_val = -ENOMEM;
-		goto add_std_failure;
+		kfree(doi_def);
+		return -ENOMEM;
 	}
 	doi_def->type = CIPSO_V4_MAP_TRANS;
 
-- 
2.30.2