diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2015-11-05 00:01:51 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-12-14 21:24:36 -0800 |
| commit | 03ecddec2c94e41d31fc1e9b5545f6ba7ced9985 (patch) | |
| tree | 1af07c930a7a438b40a7967dcbede7158a70b476 | |
| parent | 3c10560e50f845881cdecfbc22fea7939720ad38 (diff) | |
debugfs: fix refcount imbalance in start_creating
commit 0ee9608c89e81a1ccee52ecb58a7ff040e2522d9 upstream.
In debugfs' start_creating(), we pin the file system to safely access
its root. When we failed to create a file, we unpin the file system via
failed_creating() to release the mount count and eventually the reference
of the vfsmount.
However, when we run into an error during lookup_one_len() when still
in start_creating(), we only release the parent's mutex but not so the
reference on the mount. Looks like it was done in the past, but after
splitting portions of __create_file() into start_creating() and
end_creating() via 190afd81e4a5 ("debugfs: split the beginning and the
end of __create_file() off"), this seemed missed. Noticed during code
review.
Fixes: 190afd81e4a5 ("debugfs: split the beginning and the end of __create_file() off")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/debugfs/inode.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 12756040ca20..8bec8f1e4b31 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -276,8 +276,12 @@ static struct dentry *start_creating(const char *name, struct dentry *parent) dput(dentry); dentry = ERR_PTR(-EEXIST); } - if (IS_ERR(dentry)) + + if (IS_ERR(dentry)) { mutex_unlock(&d_inode(parent)->i_mutex); + simple_release_fs(&debugfs_mount, &debugfs_mount_count); + } + return dentry; } |