From e956edd0523b6b48ed367c63b0c82d8f4c447a58 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 17 Oct 2006 00:10:12 -0700 Subject: [PATCH] [PATCH] fuse: fix dereferencing dentry parent There's no locking for ->d_revalidate, so fuse_dentry_revalidate() should use dget_parent() instead of simply dereferencing ->d_parent. Due to topology changes in the directory tree the parent could become negative or be destroyed while being used. There hasn't been any reports about this yet. Signed-off-by: Miklos Szeredi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fuse/dir.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 9d0ef5e18740..cfc8f81e60d0 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -138,6 +138,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd) struct fuse_entry_out outarg; struct fuse_conn *fc; struct fuse_req *req; + struct dentry *parent; /* Doesn't hurt to "reset" the validity timeout */ fuse_invalidate_entry_cache(entry); @@ -151,8 +152,10 @@ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd) if (IS_ERR(req)) return 0; - fuse_lookup_init(req, entry->d_parent->d_inode, entry, &outarg); + parent = dget_parent(entry); + fuse_lookup_init(req, parent->d_inode, entry, &outarg); request_send(fc, req); + dput(parent); err = req->out.h.error; /* Zero nodeid is same as -ENOENT */ if (!err && !outarg.nodeid) -- 2.20.1