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 C6A63C433EF for ; Mon, 13 Jun 2022 13:46:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378712AbiFMNq2 (ORCPT ); Mon, 13 Jun 2022 09:46:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379279AbiFMNn5 (ORCPT ); Mon, 13 Jun 2022 09:43:57 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB3053F334; Mon, 13 Jun 2022 04:31:57 -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 ams.source.kernel.org (Postfix) with ESMTPS id 015F8B80E59; Mon, 13 Jun 2022 11:31:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6CDD5C34114; Mon, 13 Jun 2022 11:31:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655119914; bh=tGBlJ7JY+s3B2/qOb54Hys5f330KW69tkUwoYC4ttqk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0VUuNy2635MEfkFBWjdjPVOARutxL+9tcawq7+iSVdMNNOG6GsxbUl1FtpyQFoeuZ bJf2pMsuWMbJMxDznasNpZ/lOhslw2A8jK024Oha7ibyFc/MCoMnlAVGTjvD1LaFrn 1y/VjtOLIPmVU82861v8Lmou4Hp/TtwRBlyAINAg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust , Chuck Lever , Sasha Levin Subject: [PATCH 5.18 184/339] NFSD: Fix potential use-after-free in nfsd_file_put() Date: Mon, 13 Jun 2022 12:10:09 +0200 Message-Id: <20220613094932.258210982@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220613094926.497929857@linuxfoundation.org> References: <20220613094926.497929857@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chuck Lever [ Upstream commit b6c71c66b0ad8f2b59d9bc08c7a5079b110bec01 ] nfsd_file_put_noref() can free @nf, so don't dereference @nf immediately upon return from nfsd_file_put_noref(). Suggested-by: Trond Myklebust Fixes: 999397926ab3 ("nfsd: Clean up nfsd_file_put()") Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin --- fs/nfsd/filecache.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index 2c1b027774d4..0326bdec5de7 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -306,11 +306,12 @@ nfsd_file_put(struct nfsd_file *nf) if (test_bit(NFSD_FILE_HASHED, &nf->nf_flags) == 0) { nfsd_file_flush(nf); nfsd_file_put_noref(nf); - } else { + } else if (nf->nf_file) { nfsd_file_put_noref(nf); - if (nf->nf_file) - nfsd_file_schedule_laundrette(); - } + nfsd_file_schedule_laundrette(); + } else + nfsd_file_put_noref(nf); + if (atomic_long_read(&nfsd_filecache_count) >= NFSD_FILE_LRU_LIMIT) nfsd_file_gc(); } -- 2.35.1