From acbc372e6109c803cbee4733769d02008381740f Mon Sep 17 00:00:00 2001 From: Ondrej Mosnacek Date: Tue, 23 Jul 2019 08:50:59 +0200 Subject: [PATCH] selinux: check sidtab limit before adding a new entry 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. Cc: stable@vger.kernel.org Fixes: ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve performance") Signed-off-by: Ondrej Mosnacek Reviewed-by: Kees Cook Signed-off-by: Paul Moore --- 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..1f0a6eaa2d6a 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 = -EOVERFLOW; + if (count >= SIDTAB_MAX) + goto out_unlock; + /* insert context into new entry */ rc = -ENOMEM; dst = sidtab_do_lookup(s, count, 1);