4.14-stable review patch. If anyone has any objections, please let me know.
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From: Javier Carrasco javier.carrasco.cruz@gmail.com
commit 5c15c60e7be615f05a45cd905093a54b11f461bc upstream.
syzbot has found a use-after-free bug [1] in the powermate driver. This happens when the device is disconnected, which leads to a memory free from the powermate_device struct. When an asynchronous control message completes after the kfree and its callback is invoked, the lock does not exist anymore and hence the bug.
Use usb_kill_urb() on pm->config to cancel any in-progress requests upon device disconnection.
[1] https://syzkaller.appspot.com/bug?extid=0434ac83f907a1dbdd1e
Signed-off-by: Javier Carrasco javier.carrasco.cruz@gmail.com Reported-by: syzbot+0434ac83f907a1dbdd1e@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20230916-topic-powermate_use_after_free-v3-1-64412... Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/input/misc/powermate.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/input/misc/powermate.c +++ b/drivers/input/misc/powermate.c @@ -424,6 +424,7 @@ static void powermate_disconnect(struct pm->requires_update = 0; usb_kill_urb(pm->irq); input_unregister_device(pm->input); + usb_kill_urb(pm->config); usb_free_urb(pm->irq); usb_free_urb(pm->config); powermate_free_buffers(interface_to_usbdev(intf), pm);