diff options
| author | Namjae Jeon <linkinjeon@kernel.org> | 2026-06-21 19:59:06 +0900 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2026-06-22 20:15:06 -0500 |
| commit | 6b375be0b4e1be89e9a817880515311503a19114 (patch) | |
| tree | 3a76b57d4afeb82ee31936b02e82a4f82265a248 | |
| parent | be939e11c4724d1de3650e8bafd4c3583d9684b2 (diff) | |
| download | linux-next-6b375be0b4e1be89e9a817880515311503a19114.tar.gz linux-next-6b375be0b4e1be89e9a817880515311503a19114.zip | |
ksmbd: start file id allocation at 1
ksmbd allocates both the volatile id (per-session file table) and the
persistent id (global file table) with idr_alloc_cyclic() starting at 0.
The first open after the module loads therefore gets volatile id 0 and
persistent id 0, and ksmbd returns an SMB2 FileId of {0, 0} in the create
response.
Clients treat an all-zero FileId as a null handle. smbtorture's
smb2_util_handle_empty() considers {0, 0} empty, so tests that guard the
close with it (e.g. smb2.oplock.statopen1, smb2.lease.statopen*) never
close that first handle. The leaked open keeps the inode's oplock count
non-zero, so a later batch oplock request on the same file is downgraded
to level II and the test fails.
Start the id allocation at 1 (KSMBD_START_FID) so no handle is ever
assigned a {0, 0} FileId, matching the behaviour of other SMB servers.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
| -rw-r--r-- | fs/smb/server/vfs_cache.c | 3 | ||||
| -rw-r--r-- | fs/smb/server/vfs_cache.h | 7 |
2 files changed, 8 insertions, 2 deletions
diff --git a/fs/smb/server/vfs_cache.c b/fs/smb/server/vfs_cache.c index 11b51320b96e..7495166b0262 100644 --- a/fs/smb/server/vfs_cache.c +++ b/fs/smb/server/vfs_cache.c @@ -992,7 +992,8 @@ static int __open_id(struct ksmbd_file_table *ft, struct ksmbd_file *fp, idr_preload(KSMBD_DEFAULT_GFP); write_lock(&ft->lock); - ret = idr_alloc_cyclic(ft->idr, fp, 0, INT_MAX - 1, GFP_NOWAIT); + ret = idr_alloc_cyclic(ft->idr, fp, KSMBD_START_FID, INT_MAX - 1, + GFP_NOWAIT); if (ret >= 0) { id = ret; ret = 0; diff --git a/fs/smb/server/vfs_cache.h b/fs/smb/server/vfs_cache.h index f85021c11d6e..287f3e675cd3 100644 --- a/fs/smb/server/vfs_cache.h +++ b/fs/smb/server/vfs_cache.h @@ -23,7 +23,12 @@ #define FILE_GENERIC_WRITE 0x120116 #define FILE_GENERIC_EXECUTE 0X1200a0 -#define KSMBD_START_FID 0 +/* + * Start volatile/persistent file id allocation at 1. A file id of 0 yields an + * SMB2 FileId of {0, 0}, which clients (e.g. Windows, Samba) treat as a null + * handle and never close, leaking the open on the server. + */ +#define KSMBD_START_FID 1 #define KSMBD_NO_FID (INT_MAX) #define SMB2_NO_FID (0xFFFFFFFFFFFFFFFFULL) |