| Message ID | 20210608175936.584233292@linuxfoundation.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | None | expand |
On 6/8/21 8:27 PM, Greg Kroah-Hartman wrote: > From: Lin Ma <linma@zju.edu.cn> > > commit e305509e678b3a4af2b3cfd410f409f7cdaabb52 upstream. > > The hci_sock_dev_event() function will cleanup the hdev object for > sockets even if this object may still be in used within the > hci_sock_bound_ioctl() function, result in UAF vulnerability. > > This patch replace the BH context lock to serialize these affairs > and prevent the race condition. > > Signed-off-by: Lin Ma <linma@zju.edu.cn> > Signed-off-by: Marcel Holtmann <marcel@holtmann.org> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > --- > net/bluetooth/hci_sock.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > --- a/net/bluetooth/hci_sock.c > +++ b/net/bluetooth/hci_sock.c > @@ -755,7 +755,7 @@ void hci_sock_dev_event(struct hci_dev * > /* Detach sockets from device */ > read_lock(&hci_sk_list.lock); > sk_for_each(sk, &hci_sk_list.head) { > - bh_lock_sock_nested(sk); > + lock_sock(sk); > if (hci_pi(sk)->hdev == hdev) { > hci_pi(sk)->hdev = NULL; > sk->sk_err = EPIPE; > @@ -764,7 +764,7 @@ void hci_sock_dev_event(struct hci_dev * > > hci_dev_put(hdev); > } > - bh_unlock_sock(sk); > + release_sock(sk); > } > read_unlock(&hci_sk_list.lock); > } > > This patch is buggy. lock_sock() can sleep. But the read_lock(&hci_sk_list.lock) two lines before is not going to allow the sleep. Hmmm ?
On Mon, Jun 14, 2021 at 04:15:02PM +0200, Eric Dumazet wrote: > > > On 6/8/21 8:27 PM, Greg Kroah-Hartman wrote: > > From: Lin Ma <linma@zju.edu.cn> > > > > commit e305509e678b3a4af2b3cfd410f409f7cdaabb52 upstream. > > > > The hci_sock_dev_event() function will cleanup the hdev object for > > sockets even if this object may still be in used within the > > hci_sock_bound_ioctl() function, result in UAF vulnerability. > > > > This patch replace the BH context lock to serialize these affairs > > and prevent the race condition. > > > > Signed-off-by: Lin Ma <linma@zju.edu.cn> > > Signed-off-by: Marcel Holtmann <marcel@holtmann.org> > > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > --- > > net/bluetooth/hci_sock.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > --- a/net/bluetooth/hci_sock.c > > +++ b/net/bluetooth/hci_sock.c > > @@ -755,7 +755,7 @@ void hci_sock_dev_event(struct hci_dev * > > /* Detach sockets from device */ > > read_lock(&hci_sk_list.lock); > > sk_for_each(sk, &hci_sk_list.head) { > > - bh_lock_sock_nested(sk); > > + lock_sock(sk); > > if (hci_pi(sk)->hdev == hdev) { > > hci_pi(sk)->hdev = NULL; > > sk->sk_err = EPIPE; > > @@ -764,7 +764,7 @@ void hci_sock_dev_event(struct hci_dev * > > > > hci_dev_put(hdev); > > } > > - bh_unlock_sock(sk); > > + release_sock(sk); > > } > > read_unlock(&hci_sk_list.lock); > > } > > > > > > > This patch is buggy. > > lock_sock() can sleep. > > But the read_lock(&hci_sk_list.lock) two lines before is not going to allow the sleep. > > Hmmm ? > > Odd, Lin, did you see any problems with your testing of this?
--- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -755,7 +755,7 @@ void hci_sock_dev_event(struct hci_dev * /* Detach sockets from device */ read_lock(&hci_sk_list.lock); sk_for_each(sk, &hci_sk_list.head) { - bh_lock_sock_nested(sk); + lock_sock(sk); if (hci_pi(sk)->hdev == hdev) { hci_pi(sk)->hdev = NULL; sk->sk_err = EPIPE; @@ -764,7 +764,7 @@ void hci_sock_dev_event(struct hci_dev * hci_dev_put(hdev); } - bh_unlock_sock(sk); + release_sock(sk); } read_unlock(&hci_sk_list.lock); }