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From: Ondrej Mosnacek <omosnace@redhat.com>
To: selinux@vger.kernel.org, Paul Moore <paul@paul-moore.com>
Cc: NitinGote <nitin.r.gote@intel.com>,
	kernel-hardening@lists.openwall.com,
	Kees Cook <keescook@chromium.org>
Subject: [PATCH] selinux: check sidtab limit before adding a new entry
Date: Mon, 22 Jul 2019 15:21:11 +0200	[thread overview]
Message-ID: <20190722132111.25743-1-omosnace@redhat.com> (raw)

We need to error out when trying to add an entry above SIDTAB_MAX in
sidtab_reverse_lookup() to avoid overflow on the odd chance that this
happens.

Fixes: ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve performance")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
---
 security/selinux/ss/sidtab.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c
index e63a90ff2728..54c1ba1e79ab 100644
--- a/security/selinux/ss/sidtab.c
+++ b/security/selinux/ss/sidtab.c
@@ -286,6 +286,11 @@ static int sidtab_reverse_lookup(struct sidtab *s, struct context *context,
 		++count;
 	}
 
+	/* bail out if we already reached max entries */
+	rc = -ENOMEM;
+	if (count == SIDTAB_MAX)
+		goto out_unlock;
+
 	/* insert context into new entry */
 	rc = -ENOMEM;
 	dst = sidtab_do_lookup(s, count, 1);
-- 
2.21.0


             reply	other threads:[~2019-07-22 13:45 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-22 13:21 Ondrej Mosnacek [this message]
2019-07-22 14:17 ` [PATCH] selinux: check sidtab limit before adding a new entry William Roberts
2019-07-23  6:48   ` Ondrej Mosnacek
2019-07-22 16:50 ` Kees Cook
2019-07-23  0:36   ` Paul Moore
2019-07-23  6:48   ` Ondrej Mosnacek

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