Re: [PATCH] Bluetooth: sco: Fix lock_sock() blockage by memcpy_from_msg()

Hi Takashi,

The sco_send_frame() also takes lock_sock() during memcpy_from_msg()
call that may be endlessly blocked by a task with userfaultd
technique, and this will result in a hung task watchdog trigger.

Just like the similar fix for hci_sock_sendmsg() in commit
92c685dc5de0 ("Bluetooth: reorganize functions..."), this patch moves
the  memcpy_from_msg() out of lock_sock() for addressing the hang.

This should be the last piece for fixing CVE-2021-3640 after a few
already queued fixes.

Signed-off-by: Takashi Iwai <redacted>
---
net/bluetooth/sco.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)

patch has been applied to bluetooth-next tree.

Regards

Marcel