diff options
| author | Namjae Jeon <linkinjeon@kernel.org> | 2023-10-04 18:31:03 +0900 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2023-10-04 20:21:48 -0500 |
| commit | 75ac9a3dd65f7eab4d12b0a0f744234b5300a491 (patch) | |
| tree | c54b6fd1e2697dbfd7917749fceb433e9bf4ae9f | |
| parent | 7ca9da7d873ee8024e9548d3366101c2b6843eab (diff) | |
| download | vfs-75ac9a3dd65f7eab4d12b0a0f744234b5300a491.tar.gz | |
ksmbd: fix race condition from parallel smb2 lock requests
There is a race condition issue between parallel smb2 lock request.
Time
+
Thread A | Thread A
smb2_lock | smb2_lock
|
insert smb_lock to lock_list |
spin_unlock(&work->conn->llist_lock) |
|
| spin_lock(&conn->llist_lock);
| kfree(cmp_lock);
|
// UAF! |
list_add(&smb_lock->llist, &rollback_list) +
This patch swaps the line for adding the smb lock to the rollback list and
adding the lock list of connection to fix the race issue.
Reported-by: luosili <rootlab@huawei.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
| -rw-r--r-- | fs/smb/server/smb2pdu.c | 12 |
1 files changed, 1 insertions, 11 deletions
diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index e774c9855f7ff..fd6f05786ac2a 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -7038,10 +7038,6 @@ skip: ksmbd_debug(SMB, "would have to wait for getting lock\n"); - spin_lock(&work->conn->llist_lock); - list_add_tail(&smb_lock->clist, - &work->conn->lock_list); - spin_unlock(&work->conn->llist_lock); list_add(&smb_lock->llist, &rollback_list); argv = kmalloc(sizeof(void *), GFP_KERNEL); @@ -7072,9 +7068,6 @@ skip: if (work->state != KSMBD_WORK_ACTIVE) { list_del(&smb_lock->llist); - spin_lock(&work->conn->llist_lock); - list_del(&smb_lock->clist); - spin_unlock(&work->conn->llist_lock); locks_free_lock(flock); if (work->state == KSMBD_WORK_CANCELLED) { @@ -7094,19 +7087,16 @@ skip: } list_del(&smb_lock->llist); - spin_lock(&work->conn->llist_lock); - list_del(&smb_lock->clist); - spin_unlock(&work->conn->llist_lock); release_async_work(work); goto retry; } else if (!rc) { + list_add(&smb_lock->llist, &rollback_list); spin_lock(&work->conn->llist_lock); list_add_tail(&smb_lock->clist, &work->conn->lock_list); list_add_tail(&smb_lock->flist, &fp->lock_list); spin_unlock(&work->conn->llist_lock); - list_add(&smb_lock->llist, &rollback_list); ksmbd_debug(SMB, "successful in taking lock\n"); } else { goto out; |