This is a note to let you know that I've just added the patch titled
ufs: Fix possible deadlock when looking up directories
to the 4.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ufs-fix-possible-deadlock-when-looking-up-directories.patch
and it can be found in the queue-4.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 514d748f69c97a51a2645eb198ac5c6218f22ff9 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@xxxxxxx>
Date: Tue, 2 Jun 2015 11:26:34 +0200
Subject: ufs: Fix possible deadlock when looking up directories
From: Jan Kara <jack@xxxxxxx>
commit 514d748f69c97a51a2645eb198ac5c6218f22ff9 upstream.
Commit e4502c63f56aeca88 (ufs: deal with nfsd/iget races) made ufs
create inodes with I_NEW flag set. However ufs_mkdir() never cleared
this flag. Thus if someone ever tried to lookup the directory by inode
number, he would deadlock waiting for I_NEW to be cleared. Luckily this
mostly happens only if the filesystem is exported over NFS since
otherwise we have the inode attached to dentry and don't look it up by
inode number. In rare cases dentry can get freed without inode being
freed and then we'd hit the deadlock even without NFS export.
Fix the problem by clearing I_NEW before instantiating new directory
inode.
Fixes: e4502c63f56aeca887ced37f24e0def1ef11cec8
Reported-by: Fabian Frederick <fabf@xxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ufs/namei.c | 1 +
1 file changed, 1 insertion(+)
--- a/fs/ufs/namei.c
+++ b/fs/ufs/namei.c
@@ -212,6 +212,7 @@ static int ufs_mkdir(struct inode * dir,
goto out_fail;
unlock_ufs(dir->i_sb);
+ unlock_new_inode(inode);
d_instantiate(dentry, inode);
out:
return err;
Patches currently in stable-queue which might be from jack@xxxxxxx are
queue-4.1/ufs-fix-possible-deadlock-when-looking-up-directories.patch
queue-4.1/ufs-fix-warning-from-unlock_new_inode.patch
queue-4.1/fs-ufs-restore-s_lock-mutex.patch
queue-4.1/fs-ufs-revert-ufs-fix-deadlocks-introduced-by-sb-mutex-merge.patch
queue-4.1/fs-fix-s_nosec-handling.patch
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