HID: debug: fix the ring buffer implementation
commit 13054abbaa4f1fd4e6f3b4b63439ec033b4c8035 upstream. Ring buffer implementation in hid_debug_event() and hid_debug_events_read() is strange allowing lost or corrupted data. After commit 717adfda ("HID: debug: check length before copy_to_user()") it is possible to enter an infinite loop in hid_debug_events_read() by providing 0 as count, this locks up a system. Fix this by rewriting the ring buffer implementation with kfifo and simplify the code. This fixes CVE-2019-3819. v2: fix an execution logic and add a comment v3: use __set_current_state() instead of set_current_state() Link: https://bugzilla.redhat.com/show_bug.cgi?id=1669187 Cc: stable@vger.kernel.org # v4.18+ Fixes: cd667ce2 ("HID: use debugfs for events/reports dumping") Fixes: 717adfda ("HID: debug: check length before copy_to_user()") Signed-off-by: NVladis Dronov <vdronov@redhat.com> Reviewed-by: NOleg Nesterov <oleg@redhat.com> Signed-off-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Showing
想要评论请 注册 或 登录