Thanks for your reply and interests. Our static analysis tool is still
to be improved, and any feedback on it would be appreciated.
On 2023/4/29 5:24, Luiz Augusto von Dentz wrote:
Hi,
On Fri, Apr 28, 2023 at 3:27 AM Li Tuo <islituo@xxxxxxxxx> wrote:
Hello,
Our static analysis tool finds a possible data race in the l2cap protocol
in Linux 6.3.0-rc7:
In most calling contexts, the variable sk->sk_socket is accessed
with holding the lock sk->sk_callback_lock. Here is an example:
l2cap_sock_accept() --> Line 346 in net/bluetooth/l2cap_sock.c
bt_accept_dequeue() --> Line 368 in net/bluetooth/l2cap_sock.c
sock_graft() --> Line 240 in net/bluetooth/af_bluetooth.c
write_lock_bh(&sk->sk_callback_lock); --> Line 2081 in include/net/sock.h (Lock sk->sk_callback_lock)
sk_set_socket() --> Line 2084 in include/net/sock.h
sk->sk_socket = sock; --> Line 2054 in include/net/sock.h (Access sk->sk_socket)
However, in the following calling context:
sco_sock_shutdown() --> Line 1227 in net/bluetooth/sco.c
__sco_sock_close() --> Line 1243 in net/bluetooth/sco.c
BT_DBG(..., sk->sk_socket); --> Line 431 in net/bluetooth/sco.c (Access sk->sk_socket)
the variable sk->sk_socket is accessed without holding the lock
sk->sk_callback_lock, and thus a data race may occur.
Reported-by: BassCheck <bass@xxxxxxxxxxx>
Need to check in detail what it means to hold the sk_callback_lock,
btw is this static analysis tool of yours something public that we can
use in our CI to detect these problems?
