On Fri, Feb 18, 2022 at 02:29:55PM +0900, Daehwan Jung wrote: > There's no lock for rndis response list. It could cause list corruption > if two different list_add at the same time like below. > It's better to add in rndis_add_response / rndis_free_response > / rndis_get_next_response to prevent any race condition on response list. > > [ 361.894299] [1: irq/191-dwc3:16979] list_add corruption. > next->prev should be prev (ffffff80651764d0), > but was ffffff883dc36f80. (next=ffffff80651764d0). > > [ 361.904380] [1: irq/191-dwc3:16979] Call trace: > [ 361.904391] [1: irq/191-dwc3:16979] __list_add_valid+0x74/0x90 > [ 361.904401] [1: irq/191-dwc3:16979] rndis_msg_parser+0x168/0x8c0 > [ 361.904409] [1: irq/191-dwc3:16979] rndis_command_complete+0x24/0x84 > [ 361.904417] [1: irq/191-dwc3:16979] usb_gadget_giveback_request+0x20/0xe4 > [ 361.904426] [1: irq/191-dwc3:16979] dwc3_gadget_giveback+0x44/0x60 > [ 361.904434] [1: irq/191-dwc3:16979] dwc3_ep0_complete_data+0x1e8/0x3a0 > [ 361.904442] [1: irq/191-dwc3:16979] dwc3_ep0_interrupt+0x29c/0x3dc > [ 361.904450] [1: irq/191-dwc3:16979] dwc3_process_event_entry+0x78/0x6cc > [ 361.904457] [1: irq/191-dwc3:16979] dwc3_process_event_buf+0xa0/0x1ec > [ 361.904465] [1: irq/191-dwc3:16979] dwc3_thread_interrupt+0x34/0x5c > > Fixes: f6281af9d62e ("usb: gadget: rndis: use list_for_each_entry_safe") > Signed-off-by: Daehwan Jung <dh10.jung@xxxxxxxxxxx> > --- > drivers/usb/gadget/function/rndis.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/usb/gadget/function/rndis.c b/drivers/usb/gadget/function/rndis.c > index b7ccf1803656..b4d58324e2d2 100644 > --- a/drivers/usb/gadget/function/rndis.c > +++ b/drivers/usb/gadget/function/rndis.c > @@ -1011,16 +1011,21 @@ void rndis_add_hdr(struct sk_buff *skb) > } > EXPORT_SYMBOL_GPL(rndis_add_hdr); > > +/* add spinlock to prevent race condition for rndis response list */ > +static DEFINE_SPINLOCK(resp_lock); Shouldn't this be one lock per rndis_params structure, and not a global one for the whole driver? thanks, greg k-h