From: "Benjamin Coddington" <bcodding@redhat.com>
To: anna.schumaker@netapp.com
Cc: linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org,
syzkaller-bugs@googlegroups.com, trond.myklebust@hammerspace.com,
"Roberto Bergantinos Corpas" <rbergant@redhat.com>,
syzbot <syzbot+228a82b263b5da91883d@syzkaller.appspotmail.com>
Subject: Re: WARNING: locking bug in nfs_get_client
Date: Thu, 09 May 2019 07:37:50 -0400 [thread overview]
Message-ID: <FE8462BD-2B07-4AC1-A739-E3D429DDA134@redhat.com> (raw)
In-Reply-To: <C6C33F7F-8CD2-4E0F-82BA-5443133FBB54@redhat.com>
I think nfs_get_client and nfs_match_client could use a refactor.. but
the
trivial fix is:
8<---------------------------------
From 4ef2fc5912c5980890e781f8c0d941330254c100 Mon Sep 17 00:00:00 2001
Message-Id:
<4ef2fc5912c5980890e781f8c0d941330254c100.1557401467.git.bcodding@redhat.com>
From: Benjamin Coddington <bcodding@redhat.com>
Date: Thu, 9 May 2019 07:25:21 -0400
Subject: [PATCH] NFS: Fix a double unlock from nfs_match,get_client
Now that nfs_match_client drops the nfs_client_lock, we should be
careful
to always return it in the same condition: locked.
Fixes: 950a578c6128 ("NFS: make nfs_match_client killable")
Reported-by: syzbot+228a82b263b5da91883d@syzkaller.appspotmail.com
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
---
fs/nfs/client.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 06e8719655f0..da74c4c4a244 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -299,9 +299,9 @@ static struct nfs_client *nfs_match_client(const
struct nfs_client_initdata *dat
spin_unlock(&nn->nfs_client_lock);
error = nfs_wait_client_init_complete(clp);
nfs_put_client(clp);
+ spin_lock(&nn->nfs_client_lock);
if (error < 0)
return ERR_PTR(error);
- spin_lock(&nn->nfs_client_lock);
goto again;
}
--
2.20.1
next prev parent reply other threads:[~2019-05-09 11:37 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-09 0:17 WARNING: locking bug in nfs_get_client syzbot
2019-05-09 2:46 ` syzbot
2019-05-09 10:55 ` Benjamin Coddington
2019-05-09 11:37 ` Benjamin Coddington [this message]
2019-05-09 12:06 ` Schumaker, Anna
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