| Message ID | 1645162195-54476-1-git-send-email-dh10.jung@samsung.com |
|---|---|
| State | New |
| Headers | show |
| Series | usb: gadget: function: add spinlock for rndis response list | expand |
On Fri, Feb 18, 2022 at 08:57:45AM +0100, Greg Kroah-Hartman wrote: > 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@samsung.com> > > --- > > 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? > I agree with your comment. I'm going to modify and push it again. Thanks for the comment. Best Regards, Jung Daehwan > thanks, > > greg k-h >
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); + void rndis_free_response(struct rndis_params *params, u8 *buf) { rndis_resp_t *r, *n; + spin_lock(&resp_lock); list_for_each_entry_safe(r, n, ¶ms->resp_queue, list) { if (r->buf == buf) { list_del(&r->list); kfree(r); } } + spin_unlock(&resp_lock); } EXPORT_SYMBOL_GPL(rndis_free_response); @@ -1030,14 +1035,17 @@ u8 *rndis_get_next_response(struct rndis_params *params, u32 *length) if (!length) return NULL; + spin_lock(&resp_lock); list_for_each_entry_safe(r, n, ¶ms->resp_queue, list) { if (!r->send) { r->send = 1; *length = r->length; + spin_unlock(&resp_lock); return r->buf; } } + spin_unlock(&resp_lock); return NULL; } EXPORT_SYMBOL_GPL(rndis_get_next_response); @@ -1054,7 +1062,9 @@ static rndis_resp_t *rndis_add_response(struct rndis_params *params, u32 length) r->length = length; r->send = 0; + spin_lock(&resp_lock); list_add_tail(&r->list, ¶ms->resp_queue); + spin_unlock(&resp_lock); return r; }
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@samsung.com> --- drivers/usb/gadget/function/rndis.c | 10 ++++++++++ 1 file changed, 10 insertions(+)