From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 84D18C433F5 for ; Sun, 9 Oct 2022 22:48:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233030AbiJIWsG (ORCPT ); Sun, 9 Oct 2022 18:48:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233007AbiJIWqV (ORCPT ); Sun, 9 Oct 2022 18:46:21 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E8E21CB1B; Sun, 9 Oct 2022 15:23:16 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id AAE9A60C32; Sun, 9 Oct 2022 22:21:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D78F3C433C1; Sun, 9 Oct 2022 22:21:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1665354113; bh=Jad87ZPGbOMCQZjFg6peU5RSSRiKnGTlnlSYbcbi8sA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SNNRwIbNXFy/NinM7DMiSFiL4BOBC1ME7Zyl0vaqLHvW4KJJEIU6rlTXjAXZMNZ5i eyf9c2hq041UD+EtGRoyTAAGjivZj62jK9tuDuM7oE3Sxwgb5n7x1JYVQqPxlrrnSu mrhhO59HuCKWoi/Gw/1xsWsW5c8ohviV+x2FNsS6hAECLYD+kzjZtfra+WtKfn/2G8 f5RgvBqEfClBKZvUZfAM//zlzUzhhARPCUrDepADsvo1bVIUC/APdi0j3pn6RInkev ZvvfnlguzgZkZFthqIqiIvg9VmWkmxf6h5L1k6/4rXe9DZGbmdk/+7fW+f3UjithkM HAwkSN6iXMRdg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Khalid Masum , Herbert Xu , syzbot+5ec9bb042ddfe9644773@syzkaller.appspotmail.com, Steffen Klassert , Sasha Levin , davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.10 09/34] xfrm: Update ipcomp_scratches with NULL when freed Date: Sun, 9 Oct 2022 18:21:03 -0400 Message-Id: <20221009222129.1218277-9-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221009222129.1218277-1-sashal@kernel.org> References: <20221009222129.1218277-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Khalid Masum [ Upstream commit 8a04d2fc700f717104bfb95b0f6694e448a4537f ] Currently if ipcomp_alloc_scratches() fails to allocate memory ipcomp_scratches holds obsolete address. So when we try to free the percpu scratches using ipcomp_free_scratches() it tries to vfree non existent vm area. Described below: static void * __percpu *ipcomp_alloc_scratches(void) { ... scratches = alloc_percpu(void *); if (!scratches) return NULL; ipcomp_scratches does not know about this allocation failure. Therefore holding the old obsolete address. ... } So when we free, static void ipcomp_free_scratches(void) { ... scratches = ipcomp_scratches; Assigning obsolete address from ipcomp_scratches if (!scratches) return; for_each_possible_cpu(i) vfree(*per_cpu_ptr(scratches, i)); Trying to free non existent page, causing warning: trying to vfree existent vm area. ... } Fix this breakage by updating ipcomp_scrtches with NULL when scratches is freed Suggested-by: Herbert Xu Reported-by: syzbot+5ec9bb042ddfe9644773@syzkaller.appspotmail.com Tested-by: syzbot+5ec9bb042ddfe9644773@syzkaller.appspotmail.com Signed-off-by: Khalid Masum Acked-by: Herbert Xu Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin --- net/xfrm/xfrm_ipcomp.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c index 0814320472f1..24ac6805275e 100644 --- a/net/xfrm/xfrm_ipcomp.c +++ b/net/xfrm/xfrm_ipcomp.c @@ -212,6 +212,7 @@ static void ipcomp_free_scratches(void) vfree(*per_cpu_ptr(scratches, i)); free_percpu(scratches); + ipcomp_scratches = NULL; } static void * __percpu *ipcomp_alloc_scratches(void) -- 2.35.1