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 85C2CC38A2D for ; Mon, 24 Oct 2022 12:38:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234024AbiJXMi3 (ORCPT ); Mon, 24 Oct 2022 08:38:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45248 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234489AbiJXMfK (ORCPT ); Mon, 24 Oct 2022 08:35:10 -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 E2DD25FF40; Mon, 24 Oct 2022 05:05:29 -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 687F5612DB; Mon, 24 Oct 2022 12:02:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7BA1EC433C1; Mon, 24 Oct 2022 12:02:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666612953; bh=/XB4y2LpgVtKSLfj2FRGEXMsobFlbWAbbPzG5tqVxqA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jrqRm/k1b/V6HcATXfa9l86fIiZ6IF0qWDEEhRh7Aoz5Ree4YSeYoj/qAH3GxycIB x3r2AyBE3Wur04PIUccxhaIURwkSnRKKRvs/LAnWAH9CiYxvqvMcKokHeKE60+0qt6 3vX1IMAsVfMuNFFVSrE4pogp2RTRtiyIH7e9BAzQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Herbert Xu , syzbot+5ec9bb042ddfe9644773@syzkaller.appspotmail.com, Khalid Masum , Steffen Klassert , Sasha Levin Subject: [PATCH 4.19 181/229] xfrm: Update ipcomp_scratches with NULL when freed Date: Mon, 24 Oct 2022 13:31:40 +0200 Message-Id: <20221024113004.944366721@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024112959.085534368@linuxfoundation.org> References: <20221024112959.085534368@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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 a00ec715aa46..32aed1d0f6ee 100644 --- a/net/xfrm/xfrm_ipcomp.c +++ b/net/xfrm/xfrm_ipcomp.c @@ -216,6 +216,7 @@ 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