From c138325fb8713472d5a0c3c7258b9131bab40725 Mon Sep 17 00:00:00 2001 From: Ondrej Mosnacek Date: Tue, 13 Nov 2018 16:16:08 +0100 Subject: [PATCH 1/2] selinux: check length properly in SCTP bind hook selinux_sctp_bind_connect() must verify if the address buffer has sufficient length before accessing the 'sa_family' field. See __sctp_connect() for a similar check. The length of the whole address ('len') is already checked in the callees. Reported-by: Qian Cai Fixes: d452930fd3b9 ("selinux: Add SCTP support") Cc: # 4.17+ Cc: Richard Haines Signed-off-by: Ondrej Mosnacek Tested-by: Qian Cai Signed-off-by: Paul Moore --- security/selinux/hooks.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 18b98b5e1e3c46..fe251c6f09f104 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -5318,6 +5318,9 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname, addr_buf = address; while (walk_size < addrlen) { + if (walk_size + sizeof(sa_family_t) > addrlen) + return -EINVAL; + addr = addr_buf; switch (addr->sa_family) { case AF_UNSPEC: From 877181a8d9dc663f7a73f77f50af714d7888ec3b Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Tue, 13 Nov 2018 21:44:33 -0500 Subject: [PATCH 2/2] selinux: fix non-MLS handling in mls_context_to_sid() Commit 95ffe194204a ("selinux: refactor mls_context_to_sid() and make it stricter") inadvertently changed how we handle labels that did not contain MLS information. This patch restores the proper behavior in mls_context_to_sid() and adds a comment explaining the proper behavior to help ensure this doesn't happen again. Fixes: 95ffe194204a ("selinux: refactor mls_context_to_sid() and make it stricter") Reported-by: Stephen Smalley Signed-off-by: Paul Moore --- security/selinux/ss/mls.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c index 2fe459df3c858d..b7efa2296969c6 100644 --- a/security/selinux/ss/mls.c +++ b/security/selinux/ss/mls.c @@ -245,9 +245,13 @@ int mls_context_to_sid(struct policydb *pol, char *rangep[2]; if (!pol->mls_enabled) { - if ((def_sid != SECSID_NULL && oldc) || (*scontext) == '\0') - return 0; - return -EINVAL; + /* + * With no MLS, only return -EINVAL if there is a MLS field + * and it did not come from an xattr. + */ + if (oldc && def_sid == SECSID_NULL) + return -EINVAL; + return 0; } /*