diff options
| author | Amir Goldstein <amir73il@gmail.com> | 2025-06-27 12:48:35 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-15 12:13:51 +0200 |
| commit | de07e1183139f24182a37e5794a7bb9867d60282 (patch) | |
| tree | 0a523e1e69c7e48cbcc2de0c25a2265824d613aa | |
| parent | faa05c6d5ae1efc000a06c53f7166012db46b74c (diff) | |
fanotify: sanitize handle_type values when reporting fid
[ Upstream commit 8631e01c2c5d1fe6705bcc0d733a0b7a17d3daac ]
Unlike file_handle, type and len of struct fanotify_fh are u8.
Traditionally, filesystem return handle_type < 0xff, but there
is no enforecement for that in vfs.
Add a sanity check in fanotify to avoid truncating handle_type
if its value is > 0xff.
Fixes: 7cdafe6cc4a6 ("exportfs: check for error return value from exportfs_encode_*()")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250627104835.184495-1-amir73il@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | fs/notify/fanotify/fanotify.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 224bccaab4cc..bb00e1e16838 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -441,7 +441,13 @@ static int fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode, dwords = fh_len >> 2; type = exportfs_encode_fid(inode, buf, &dwords); err = -EINVAL; - if (type <= 0 || type == FILEID_INVALID || fh_len != dwords << 2) + /* + * Unlike file_handle, type and len of struct fanotify_fh are u8. + * Traditionally, filesystem return handle_type < 0xff, but there + * is no enforecement for that in vfs. + */ + BUILD_BUG_ON(MAX_HANDLE_SZ > 0xff || FILEID_INVALID > 0xff); + if (type <= 0 || type >= FILEID_INVALID || fh_len != dwords << 2) goto out_err; fh->type = type; |