Commit 0cdfa9e6 authored by Phil Turnbull's avatar Phil Turnbull Committed by Kalle Valo
Browse files

wifi: wilc1000: validate number of channels 



There is no validation of 'e->no_of_channels' which can trigger an
out-of-bounds write in the following 'memset' call. Validate that the
number of channels does not extends beyond the size of the channel list
element.

Signed-off-by: default avatarPhil Turnbull <philipturnbull@github.com>
Tested-by: default avatarAjay Kathat <ajay.kathat@microchip.com>
Acked-by: default avatarAjay Kathat <ajay.kathat@microchip.com>
Signed-off-by: default avatarKalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20221123153543.8568-5-philipturnbull@github.com
parent f9b62f98

drivers/net/wireless/microchip/wilc1000/cfg80211.c

+16 −6
Original line number Diff line number Diff line
@@ -981,19 +981,29 @@ static inline void wilc_wfi_cfg_parse_ch_attr(u8 *buf, u32 len, u8 sta_ch) 
	}



	if (ch_list_idx) {

		u16 attr_size;

		struct wilc_ch_list_elem *e;

		int i;

		u16 elem_size;



		ch_list = (struct wilc_attr_ch_list *)&buf[ch_list_idx];

		attr_size = le16_to_cpu(ch_list->attr_len);

		for (i = 0; i < attr_size;) {

		/* the number of bytes following the final 'elem' member */

		elem_size = le16_to_cpu(ch_list->attr_len) -

			(sizeof(*ch_list) - sizeof(struct wilc_attr_entry));

		for (unsigned int i = 0; i < elem_size;) {

			struct wilc_ch_list_elem *e;



			e = (struct wilc_ch_list_elem *)(ch_list->elem + i);



			i += sizeof(*e);

			if (i > elem_size)

				break;



			i += e->no_of_channels;

			if (i > elem_size)

				break;



			if (e->op_class == WILC_WLAN_OPERATING_CLASS_2_4GHZ) {

				memset(e->ch_list, sta_ch, e->no_of_channels);

				break;

			}

			i += e->no_of_channels;

		}

	}