From 49fbc18378ae72a47feabee97fdb86f3cea09765 Mon Sep 17 00:00:00 2001 From: Krishna Kurapati Date: Wed, 27 Sep 2023 16:28:58 +0530 Subject: [PATCH] usb: gadget: ncm: Handle decoding of multiple NTB's in unwrap call MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit 427694cfaafa565a3db5c5ea71df6bc095dca92f upstream. When NCM is used with hosts like Windows PC, it is observed that there are multiple NTB's contained in one usb request giveback. Since the driver unwraps the obtained request data assuming only one NTB is present, we loose the subsequent NTB's present resulting in data loss. Fix this by checking the parsed block length with the obtained data length in usb request and continue parsing after the last byte of current NTB. Cc: stable@vger.kernel.org Fixes: 9f6ce4240a2b ("usb: gadget: f_ncm.c added") Signed-off-by: Krishna Kurapati Reviewed-by: Maciej Żenczykowski Link: https://lore.kernel.org/r/20230927105858.12950-1-quic_kriskura@quicinc.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/f_ncm.c | 26 +++++++++++++++++++------- 1 file changed, 19 insertions(+), 7 deletions(-) diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c index 424bb3b666dbd..faf90a2174194 100644 --- a/drivers/usb/gadget/function/f_ncm.c +++ b/drivers/usb/gadget/function/f_ncm.c @@ -1171,7 +1171,8 @@ static int ncm_unwrap_ntb(struct gether *port, struct sk_buff_head *list) { struct f_ncm *ncm = func_to_ncm(&port->func); - __le16 *tmp = (void *) skb->data; + unsigned char *ntb_ptr = skb->data; + __le16 *tmp; unsigned index, index2; int ndp_index; unsigned dg_len, dg_len2; @@ -1184,6 +1185,10 @@ static int ncm_unwrap_ntb(struct gether *port, const struct ndp_parser_opts *opts = ncm->parser_opts; unsigned crc_len = ncm->is_crc ? sizeof(uint32_t) : 0; int dgram_counter; + int to_process = skb->len; + +parse_ntb: + tmp = (__le16 *)ntb_ptr; /* dwSignature */ if (get_unaligned_le32(tmp) != opts->nth_sign) { @@ -1230,7 +1235,7 @@ static int ncm_unwrap_ntb(struct gether *port, * walk through NDP * dwSignature */ - tmp = (void *)(skb->data + ndp_index); + tmp = (__le16 *)(ntb_ptr + ndp_index); if (get_unaligned_le32(tmp) != ncm->ndp_sign) { INFO(port->func.config->cdev, "Wrong NDP SIGN\n"); goto err; @@ -1287,11 +1292,11 @@ static int ncm_unwrap_ntb(struct gether *port, if (ncm->is_crc) { uint32_t crc, crc2; - crc = get_unaligned_le32(skb->data + + crc = get_unaligned_le32(ntb_ptr + index + dg_len - crc_len); crc2 = ~crc32_le(~0, - skb->data + index, + ntb_ptr + index, dg_len - crc_len); if (crc != crc2) { INFO(port->func.config->cdev, @@ -1318,7 +1323,7 @@ static int ncm_unwrap_ntb(struct gether *port, dg_len - crc_len); if (skb2 == NULL) goto err; - skb_put_data(skb2, skb->data + index, + skb_put_data(skb2, ntb_ptr + index, dg_len - crc_len); skb_queue_tail(list, skb2); @@ -1331,10 +1336,17 @@ static int ncm_unwrap_ntb(struct gether *port, } while (ndp_len > 2 * (opts->dgram_item_len * 2)); } while (ndp_index); - dev_consume_skb_any(skb); - VDBG(port->func.config->cdev, "Parsed NTB with %d frames\n", dgram_counter); + + to_process -= block_len; + if (to_process != 0) { + ntb_ptr = (unsigned char *)(ntb_ptr + block_len); + goto parse_ntb; + } + + dev_consume_skb_any(skb); + return 0; err: skb_queue_purge(list); -- 2.39.5