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 X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 4E3FCC10F11 for ; Wed, 24 Apr 2019 14:43:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0D3D2218B0 for ; Wed, 24 Apr 2019 14:43:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556117008; bh=7+B5qob+FgaiyQhMC1k51U3e1X0YwM2C2Vys23zN5HE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ENlUiod8Q/qCHr+8pG5uS7B6dJTPp6jpv3ulwbI1qeeq8Wb2+PFLFHyt/DanaQKKk 3k4EVHbDrPEg0DlMh4RrjCi1BopHS/l6VoRI7x+y4Kntc0dN4Wcg6PUOSSp3wExZ6W dk82E3Hza/Q2As9sLu4qAuPD8I2yxqkFWuTUlWZg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731893AbfDXOkM (ORCPT ); Wed, 24 Apr 2019 10:40:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:42628 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731877AbfDXOkJ (ORCPT ); Wed, 24 Apr 2019 10:40:09 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A910821909; Wed, 24 Apr 2019 14:40:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556116809; bh=7+B5qob+FgaiyQhMC1k51U3e1X0YwM2C2Vys23zN5HE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oBjMxaqPURkKNmzDtoxJu3NWD/iJDvItnQQgiDZcrasXBQLJiTyd7reMettHzOy6u Yf8Bvgrzx8JaeD37rp5/9fEgOssmqx2jHWo5UllpG/nCj4veZRGp7AxTrwQsS7XOYY /ni2F3ymVSzzIx8kNSFGK7wm+icX3eXiFIuC/xy0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Al Viro , Sasha Levin , linux-mtd@lists.infradead.org Subject: [PATCH AUTOSEL 4.19 25/52] jffs2: fix use-after-free on symlink traversal Date: Wed, 24 Apr 2019 10:38:43 -0400 Message-Id: <20190424143911.28890-25-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190424143911.28890-1-sashal@kernel.org> References: <20190424143911.28890-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Al Viro [ Upstream commit 4fdcfab5b5537c21891e22e65996d4d0dd8ab4ca ] free the symlink body after the same RCU delay we have for freeing the struct inode itself, so that traversal during RCU pathwalk wouldn't step into freed memory. Signed-off-by: Al Viro Signed-off-by: Sasha Levin --- fs/jffs2/readinode.c | 5 ----- fs/jffs2/super.c | 5 ++++- 2 files changed, 4 insertions(+), 6 deletions(-) diff --git a/fs/jffs2/readinode.c b/fs/jffs2/readinode.c index 389ea53ea487..bccfc40b3a74 100644 --- a/fs/jffs2/readinode.c +++ b/fs/jffs2/readinode.c @@ -1414,11 +1414,6 @@ void jffs2_do_clear_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f) jffs2_kill_fragtree(&f->fragtree, deleted?c:NULL); - if (f->target) { - kfree(f->target); - f->target = NULL; - } - fds = f->dents; while(fds) { fd = fds; diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c index bb6ae387469f..05d892c79339 100644 --- a/fs/jffs2/super.c +++ b/fs/jffs2/super.c @@ -47,7 +47,10 @@ static struct inode *jffs2_alloc_inode(struct super_block *sb) static void jffs2_i_callback(struct rcu_head *head) { struct inode *inode = container_of(head, struct inode, i_rcu); - kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode)); + struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); + + kfree(f->target); + kmem_cache_free(jffs2_inode_cachep, f); } static void jffs2_destroy_inode(struct inode *inode) -- 2.19.1