[PATCH AUTOSEL 5.13 026/219] Smack: Fix wrong semantics in smk_access_entry()
From: Sasha Levin <sashal@kernel.org>
Date: 2021-09-09 12:11:06
Also in:
linux-security-module, lkml
Subsystem:
security subsystem, smack security module, the rest · Maintainers:
Paul Moore, James Morris, "Serge E. Hallyn", Casey Schaufler, Linus Torvalds
From: Tianjia Zhang <redacted> [ 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 <redacted> 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 7eabb448acab..169929c6c4eb 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c@@ -81,23 +81,22 @@ 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