From 6b1c8a9403a26cb0fed7a648916c74dc236da591 Mon Sep 17 00:00:00 2001 From: Sonali Pradhan Date: Mon, 20 Jul 2026 16:56:54 +0000 Subject: [PATCH] usb: gadget: f_ncm: Use unsigned int for ndp_index The variable ndp_index is declared as a signed integer, but it stores the return value of get_ncm(), which is unsigned. A malicious host can supply a large offset that overflows the signed ndp_index, making it negative. Because ndp_index is compared against unsigned bounds, this negative value bypasses sanity checks and leads to an out-of-bounds read when calculating the address of the NDP block (ntb_ptr + ndp_index). Fix this by changing ndp_index to unsigned int to ensure consistent unsigned comparisons throughout the function. Fixes: 370af734dfaf ("usb: gadget: NCM: RX function support multiple NDPs") Cc: stable Signed-off-by: Sonali Pradhan Link: https://patch.msgid.link/20260720165654.2224591-1-sonalipradhan@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/f_ncm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c index 64eabda2f546..bf02545b37a2 100644 --- a/drivers/usb/gadget/function/f_ncm.c +++ b/drivers/usb/gadget/function/f_ncm.c @@ -1171,7 +1171,7 @@ static int ncm_unwrap_ntb(struct gether *port, unsigned char *ntb_ptr = skb->data; __le16 *tmp; unsigned index, index2; - int ndp_index; + unsigned int ndp_index; unsigned dg_len, dg_len2; unsigned ndp_len; unsigned block_len; -- 2.47.3