diff options
| author | Amir Goldstein <amir73il@gmail.com> | 2024-10-11 11:00:21 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2024-11-15 11:34:57 +0100 |
| commit | 4a530a7c751d27f9dbd70b7fc45670cd11713b13 (patch) | |
| tree | 457b643c5b44d91433c2e903fa5ec62b823ace79 /fs/fhandle.c | |
| parent | 8e929cb546ee42c9a61d24fae60605e9e3192354 (diff) | |
fs: prepare for "explicit connectable" file handles
We would like to use the high 16bit of the handle_type field to encode
file handle traits, such as "connectable".
In preparation for this change, make sure that filesystems do not return
a handle_type value with upper bits set and that the open_by_handle_at(2)
syscall rejects these handle types.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20241011090023.655623-2-amir73il@gmail.com
Fixes: 570df4e9c23f ("ceph: snapshot nfs re-export")
Acked-by:
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/fhandle.c')
| -rw-r--r-- | fs/fhandle.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/fs/fhandle.c b/fs/fhandle.c index 82df28d45cd7..218511f38cbb 100644 --- a/fs/fhandle.c +++ b/fs/fhandle.c @@ -307,6 +307,11 @@ static int handle_to_path(int mountdirfd, struct file_handle __user *ufh, retval = -EINVAL; goto out_path; } + if (f_handle.handle_type < 0 || + FILEID_USER_FLAGS(f_handle.handle_type) & ~FILEID_VALID_USER_FLAGS) { + retval = -EINVAL; + goto out_path; + } handle = kmalloc(struct_size(handle, f_handle, f_handle.handle_bytes), GFP_KERNEL); if (!handle) { @@ -322,6 +327,8 @@ static int handle_to_path(int mountdirfd, struct file_handle __user *ufh, goto out_handle; } + /* Filesystem code should not be exposed to user flags */ + handle->handle_type &= ~FILEID_USER_FLAGS_MASK; retval = do_handle_to_path(handle, path, &ctx); out_handle: |