From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out5-smtp.messagingengine.com ([66.111.4.29]:37727 "EHLO out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725895AbeKOKLw (ORCPT ); Thu, 15 Nov 2018 05:11:52 -0500 Subject: FAILED: patch "[PATCH] ovl: fix recursive oi->lock in ovl_link()" failed to apply to 4.18-stable tree To: amir73il@gmail.com, mszeredi@redhat.com, stable@vger.kernel.org Cc: From: Date: Wed, 14 Nov 2018 16:06:14 -0800 Message-ID: <1542240374148100@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: The patch below does not apply to the 4.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >>From 6cd078702f2f33cb6b19a682de3e9184112f1a46 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Thu, 18 Oct 2018 09:45:49 +0300 Subject: [PATCH] ovl: fix recursive oi->lock in ovl_link() linking a non-copied-up file into a non-copied-up parent results in a nested call to mutex_lock_interruptible(&oi->lock). Fix this by copying up target parent before ovl_nlink_start(), same as done in ovl_rename(). ~/unionmount-testsuite$ ./run --ov -s ~/unionmount-testsuite$ ln /mnt/a/foo100 /mnt/a/dir100/ WARNING: possible recursive locking detected -------------------------------------------- ln/1545 is trying to acquire lock: 00000000bcce7c4c (&ovl_i_lock_key[depth]){+.+.}, at: ovl_copy_up_start+0x28/0x7d but task is already holding lock: 0000000026d73d5b (&ovl_i_lock_key[depth]){+.+.}, at: ovl_nlink_start+0x3c/0xc1 [SzM: this seems to be a false positive, but doing the copy-up first is harmless and removes the lockdep splat] Reported-by: syzbot+3ef5c0d1a5cb0b21e6be@syzkaller.appspotmail.com Fixes: 5f8415d6b87e ("ovl: persistent overlay inode nlink for...") Cc: # v4.13 Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 276914ae3c60..e1a55ecb7aba 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -663,6 +663,10 @@ static int ovl_link(struct dentry *old, struct inode *newdir, if (err) goto out_drop_write; + err = ovl_copy_up(new->d_parent); + if (err) + goto out_drop_write; + if (ovl_is_metacopy_dentry(old)) { err = ovl_set_redirect(old, false); if (err)