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: Phil Turnbull <philipturnbull@xxxxxxxxxx>
Tested-by: Ajay Kathat <ajay.kathat@xxxxxxxxxxxxx>
Acked-by: Ajay Kathat <ajay.kathat@xxxxxxxxxxxxx>
---
.../wireless/microchip/wilc1000/cfg80211.c | 22 ++++++++++++++-----
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/microchip/wilc1000/cfg80211.c b/drivers/net/wireless/microchip/wilc1000/cfg80211.c
index c4d5a272ccc0..b545d93c6e37 100644
--- a/drivers/net/wireless/microchip/wilc1000/cfg80211.c
+++ b/drivers/net/wireless/microchip/wilc1000/cfg80211.c
@@ -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;
}
}
--
2.34.1
