From: Pan Bian <bianpan2016@163.com>
To: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
Pan Bian <bianpan2016@163.com>
Subject: [PATCH V2] namei: free new_dentry late
Date: Sun, 25 Nov 2018 08:15:23 +0800 [thread overview]
Message-ID: <1543104923-81192-1-git-send-email-bianpan2016@163.com> (raw)
After calling dput(new_dentry), new_dentry is passed to fsnotify_move.
This may result in a use-after-free bug. This patch moves the put
operation late.
Fixes: da1ce0670c14("vfs: add cross-rename")
Signed-off-by: Pan Bian <bianpan2016@163.com>
---
V2: correct the fixes commit information
---
fs/namei.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/namei.c b/fs/namei.c
index 0cab649..8b104d9 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4498,7 +4498,6 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
unlock_two_nondirectories(source, target);
else if (target)
inode_unlock(target);
- dput(new_dentry);
if (!error) {
fsnotify_move(old_dir, new_dir, old_name.name, is_dir,
!(flags & RENAME_EXCHANGE) ? target : NULL, old_dentry);
@@ -4507,6 +4506,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
new_is_dir, NULL, new_dentry);
}
}
+ dput(new_dentry);
release_dentry_name_snapshot(&old_name);
return error;
--
2.7.4
next reply other threads:[~2018-11-25 0:15 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-25 0:15 Pan Bian [this message]
2018-11-27 9:25 ` [PATCH V2] namei: free new_dentry late Jan Kara
2018-11-27 9:57 ` PanBian
2018-11-27 10:05 ` Jan Kara
2018-11-27 10:33 ` Miklos Szeredi
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