From patchwork Tue Apr 5 07:19:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 557667 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 20033C433EF for ; Tue, 5 Apr 2022 09:13:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245324AbiDEJLq (ORCPT ); Tue, 5 Apr 2022 05:11:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52164 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244726AbiDEIwf (ORCPT ); Tue, 5 Apr 2022 04:52:35 -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 585E11AF23; Tue, 5 Apr 2022 01:42:52 -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 E717961003; Tue, 5 Apr 2022 08:42:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 037C5C385A0; Tue, 5 Apr 2022 08:42:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649148171; bh=M67CU+T4xOG6XH0wlo3yuSohmbR82pONZTeDDfPjaTs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ntu8wnMeo69V0184+m/l7gXWA2GbxPOZ6aUi/j7DCVZvKk6GlH2qTZkXv2FgKvQ/3 pDDq7RJp4yizKIVPJbIGJRcErrFUhVhjuj1ebiK2Un63otbzky3ckNN1ikah8JvkaP KVIA8XpGcaUFixTm7AcxAkWYgNV5w+x/BuxhCHjs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Howells , Sasha Levin , syzbot+6e2de48f06cdb2884bfc@syzkaller.appspotmail.com Subject: [PATCH 5.16 0258/1017] watch_queue: Actually free the watch Date: Tue, 5 Apr 2022 09:19:31 +0200 Message-Id: <20220405070401.921857691@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070354.155796697@linuxfoundation.org> References: <20220405070354.155796697@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: David Howells [ Upstream commit 3d8dcf278b1ee1eff1e90be848fa2237db4c07a7 ] free_watch() does everything barring actually freeing the watch object. Fix this by adding the missing kfree. kmemleak produces a report something like the following. Note that as an address can be seen in the first word, the watch would appear to have gone through call_rcu(). BUG: memory leak unreferenced object 0xffff88810ce4a200 (size 96): comm "syz-executor352", pid 3605, jiffies 4294947473 (age 13.720s) hex dump (first 32 bytes): e0 82 48 0d 81 88 ff ff 00 00 00 00 00 00 00 00 ..H............. 80 a2 e4 0c 81 88 ff ff 00 00 00 00 00 00 00 00 ................ backtrace: [] kmalloc include/linux/slab.h:581 [inline] [] kzalloc include/linux/slab.h:714 [inline] [] keyctl_watch_key+0xec/0x2e0 security/keys/keyctl.c:1800 [] __do_sys_keyctl+0x3c4/0x490 security/keys/keyctl.c:2016 [] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [] entry_SYSCALL_64_after_hwframe+0x44/0xae Fixes: c73be61cede5 ("pipe: Add general notification queue support") Reported-and-tested-by: syzbot+6e2de48f06cdb2884bfc@syzkaller.appspotmail.com Signed-off-by: David Howells Signed-off-by: Sasha Levin --- kernel/watch_queue.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c index 12348b41d7ad..38a135d68c05 100644 --- a/kernel/watch_queue.c +++ b/kernel/watch_queue.c @@ -398,6 +398,7 @@ static void free_watch(struct rcu_head *rcu) put_watch_queue(rcu_access_pointer(watch->queue)); atomic_dec(&watch->cred->user->nr_watches); put_cred(watch->cred); + kfree(watch); } static void __put_watch(struct kref *kref)