Commit 8861fd51 authored by Steve French's avatar Steve French
Browse files

smb3: fix lock ordering potential deadlock in cifs_sync_mid_result 



Coverity spotted that the cifs_sync_mid_result function could deadlock

"Thread deadlock (ORDER_REVERSAL) lock_order: Calling spin_lock acquires
lock TCP_Server_Info.srv_lock while holding lock TCP_Server_Info.mid_lock"

Addresses-Coverity: 1590401 ("Thread deadlock (ORDER_REVERSAL)")
Cc: stable@vger.kernel.org
Reviewed-by: default avatarShyam Prasad N <sprasad@microsoft.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 8094a600

fs/smb/client/transport.c

+3 −0
Original line number Diff line number Diff line
@@ -909,12 +909,15 @@ cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server) 
			list_del_init(&mid->qhead);

			mid->mid_flags |= MID_DELETED;

		}

		spin_unlock(&server->mid_lock);

		cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",

			 __func__, mid->mid, mid->mid_state);

		rc = -EIO;

		goto sync_mid_done;

	}

	spin_unlock(&server->mid_lock);



sync_mid_done:

	release_mid(mid);

	return rc;

}