From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:33500 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933239AbdK1Ksb (ORCPT ); Tue, 28 Nov 2017 05:48:31 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot , Mikulas Patocka , Dan Williams Subject: [PATCH 4.14 137/193] dax: fix general protection fault in dax_alloc_inode Date: Tue, 28 Nov 2017 11:26:24 +0100 Message-Id: <20171128100619.797093465@linuxfoundation.org> In-Reply-To: <20171128100613.638270407@linuxfoundation.org> References: <20171128100613.638270407@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mikulas Patocka commit 9f586fff6574f6ecbf323f92d44ffaf0d96225fe upstream. Don't crash in case of allocation failure in dax_alloc_inode. syzkaller hit the following crash on e4880bc5dfb1 kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access [..] RIP: 0010:dax_alloc_inode+0x3b/0x70 drivers/dax/super.c:348 Call Trace: alloc_inode+0x65/0x180 fs/inode.c:208 new_inode_pseudo+0x69/0x190 fs/inode.c:890 new_inode+0x1c/0x40 fs/inode.c:919 mount_pseudo_xattr+0x288/0x560 fs/libfs.c:261 mount_pseudo include/linux/fs.h:2137 [inline] dax_mount+0x2e/0x40 drivers/dax/super.c:388 mount_fs+0x66/0x2d0 fs/super.c:1223 Fixes: 7b6be8444e0f ("dax: refactor dax-fs into a generic provider...") Reported-by: syzbot Signed-off-by: Mikulas Patocka Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman --- drivers/dax/super.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -344,6 +344,9 @@ static struct inode *dax_alloc_inode(str struct inode *inode; dax_dev = kmem_cache_alloc(dax_cache, GFP_KERNEL); + if (!dax_dev) + return NULL; + inode = &dax_dev->inode; inode->i_rdev = 0; return inode;