[PATCH 4.9 19/29] usb: gadget: rndis: add spinlock for rndis response list

From: Daehwan Jung dh10.jung@samsung.com

commit aaaba1c86d04dac8e49bf508b492f81506257da3 upstream.

There's no lock for rndis response list. It could cause list corruption if there're 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") Cc: stable stable@kernel.org Signed-off-by: Daehwan Jung dh10.jung@samsung.com Link: https://lore.kernel.org/r/1645507768-77687-1-git-send-email-dh10.jung@samsun... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/gadget/function/rndis.c | 8 ++++++++ drivers/usb/gadget/function/rndis.h | 1 + 2 files changed, 9 insertions(+)

--- a/drivers/usb/gadget/function/rndis.c +++ b/drivers/usb/gadget/function/rndis.c @@ -924,6 +924,7 @@ struct rndis_params *rndis_register(void params->resp_avail = resp_avail; params->v = v; INIT_LIST_HEAD(&params->resp_queue); + spin_lock_init(&params->resp_lock); pr_debug("%s: configNr = %d\n", __func__, i);

return params; @@ -1017,12 +1018,14 @@ void rndis_free_response(struct rndis_pa { rndis_resp_t *r, *n;

+ spin_lock(&params->resp_lock); list_for_each_entry_safe(r, n, &params->resp_queue, list) { if (r->buf == buf) { list_del(&r->list); kfree(r); } } + spin_unlock(&params->resp_lock); } EXPORT_SYMBOL_GPL(rndis_free_response);

@@ -1032,14 +1035,17 @@ u8 *rndis_get_next_response(struct rndis

if (!length) return NULL;

+ spin_lock(&params->resp_lock); list_for_each_entry_safe(r, n, &params->resp_queue, list) { if (!r->send) { r->send = 1; *length = r->length; + spin_unlock(&params->resp_lock); return r->buf; } }

+ spin_unlock(&params->resp_lock); return NULL; } EXPORT_SYMBOL_GPL(rndis_get_next_response); @@ -1056,7 +1062,9 @@ static rndis_resp_t *rndis_add_response( r->length = length; r->send = 0;

+ spin_lock(&params->resp_lock); list_add_tail(&r->list, &params->resp_queue); + spin_unlock(&params->resp_lock); return r; }

--- a/drivers/usb/gadget/function/rndis.h +++ b/drivers/usb/gadget/function/rndis.h @@ -194,6 +194,7 @@ typedef struct rndis_params void (*resp_avail)(void *v); void *v; struct list_head resp_queue; + spinlock_t resp_lock; } rndis_params;

/* RNDIS Message parser and other useless functions */