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Code

usb: gadget: ncm: Handle decoding of multiple NTB's in unwrap call

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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: 9f6ce4240a ("usb: gadget: f_ncm.c added")
Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20230927105858.12950-1-quic_kriskura@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Krishna Kurapati 2023-09-27 16:28:58 +05:30 committed by Greg Kroah-Hartman
parent 33d7e37232
commit 427694cfaa
1 changed files with 19 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
drivers/usb/gadget/function/f_ncm.c
View File

@ -1156,7 +1156,8 @@ 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;
@ -1169,6 +1170,10 @@ 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) {
@ -1215,7 +1220,7 @@ 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;
@ -1272,11 +1277,11 @@ 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,
@ -1303,7 +1308,7 @@ 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);
@ -1316,10 +1321,17 @@ 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);