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CVE-2024-41062 kernel: bluetooth/l2cap: sync sock recv cb and release

Bastien Nocerarequested to merge
bnocera/centos-stream-9:wip/hadess/RHEL-51202 into main

bluetooth/l2cap: sync sock recv cb and release

JIRA: https://issues.redhat.com/browse/RHEL-51202 CVE: CVE-2024-41062

commit 89e856e124f9ae548572c56b1b70c2255705f8fe
Author: Edward Adam Davis <eadavis@qq.com>
Date:   Sat Jun 15 09:45:54 2024 +0800

    bluetooth/l2cap: sync sock recv cb and release

    The problem occurs between the system call to close the sock and hci_rx_work,
    where the former releases the sock and the latter accesses it without lock protection.

               CPU0                       CPU1
               ----                       ----
               sock_close                 hci_rx_work
               l2cap_sock_release         hci_acldata_packet
               l2cap_sock_kill            l2cap_recv_frame
               sk_free                    l2cap_conless_channel
                                          l2cap_sock_recv_cb

    If hci_rx_work processes the data that needs to be received before the sock is
    closed, then everything is normal; Otherwise, the work thread may access the
    released sock when receiving data.

    Add a chan mutex in the rx callback of the sock to achieve synchronization between
    the sock release and recv cb.

    Sock is dead, so set chan data to NULL, avoid others use invalid sock pointer.

    Reported-and-tested-by: syzbot+b7f6f8c9303466e16c8a@syzkaller.appspotmail.com
    Signed-off-by: Edward Adam Davis <eadavis@qq.com>
    Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Signed-off-by: Bastien Nocera bnocera@redhat.com

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