From patchwork Tue Dec 1 08:53:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 335755 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 487B0C71156 for ; Tue, 1 Dec 2020 09:28:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C7CD22067D for ; Tue, 1 Dec 2020 09:28:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="dfxM7Xau" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729254AbgLAJ1o (ORCPT ); Tue, 1 Dec 2020 04:27:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:37284 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388583AbgLAJBm (ORCPT ); Tue, 1 Dec 2020 04:01:42 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6A4FA2067D; Tue, 1 Dec 2020 09:01:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606813281; bh=pyLb39sxkFy3SOqNh8X0cHTtddtuP5J9fl4PhM2QnIM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dfxM7Xau10V3DsRL8v+39aU6X5cANtO+cU5w3xP5N0opAspF3S5AwN4tV3UHDmuLA Iw7HdKXDIdLHlTMdYgYeo2kYFzKearGkDxH4NjzX78Ubr5xpZvUcr6z2Ju2svqrShs WcaTspcvp+KtYjmyJ6yhbS3H7U2kaGvM+xyfFwnM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vamshi K Sthambamkadi , David Laight , Ard Biesheuvel , Sasha Levin Subject: [PATCH 4.19 44/57] efivarfs: revert "fix memory leak in efivarfs_create()" Date: Tue, 1 Dec 2020 09:53:49 +0100 Message-Id: <20201201084651.264895053@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201201084647.751612010@linuxfoundation.org> References: <20201201084647.751612010@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ard Biesheuvel [ Upstream commit ff04f3b6f2e27f8ae28a498416af2a8dd5072b43 ] The memory leak addressed by commit fe5186cf12e3 is a false positive: all allocations are recorded in a linked list, and freed when the filesystem is unmounted. This leads to double frees, and as reported by David, leads to crashes if SLUB is configured to self destruct when double frees occur. So drop the redundant kfree() again, and instead, mark the offending pointer variable so the allocation is ignored by kmemleak. Cc: Vamshi K Sthambamkadi Fixes: fe5186cf12e3 ("efivarfs: fix memory leak in efivarfs_create()") Reported-by: David Laight Signed-off-by: Ard Biesheuvel Signed-off-by: Sasha Levin --- fs/efivarfs/inode.c | 2 ++ fs/efivarfs/super.c | 1 - 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/efivarfs/inode.c b/fs/efivarfs/inode.c index 8c6ab6c95727e..7f40343b39b05 100644 --- a/fs/efivarfs/inode.c +++ b/fs/efivarfs/inode.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include @@ -106,6 +107,7 @@ static int efivarfs_create(struct inode *dir, struct dentry *dentry, var->var.VariableName[i] = '\0'; inode->i_private = var; + kmemleak_ignore(var); err = efivar_entry_add(var, &efivarfs_list); if (err) diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c index 7808a26bd33fa..834615f13f3e3 100644 --- a/fs/efivarfs/super.c +++ b/fs/efivarfs/super.c @@ -23,7 +23,6 @@ LIST_HEAD(efivarfs_list); static void efivarfs_evict_inode(struct inode *inode) { clear_inode(inode); - kfree(inode->i_private); } static const struct super_operations efivarfs_ops = {