[PATCH 6.6 074/160] wifi: wilc1000: fix u8 overflow in SSID scan buffer size calculation

Greg Kroah-Hartman
2026-04-08T18:23:30Z

From: Yasuaki Torimaru <yasuakitorimaru@gmail.com>

commit d049e56b1739101d1c4d81deedb269c52a8dbba0 upstream.

The variable valuesize is declared as u8 but accumulates the total
length of all SSIDs to scan. Each SSID contributes up to 33 bytes
(IEEE80211_MAX_SSID_LEN + 1), and with WILC_MAX_NUM_PROBED_SSID (10)
SSIDs the total can reach 330, which wraps around to 74 when stored
in a u8.

This causes kmalloc to allocate only 75 bytes while the subsequent
memcpy writes up to 331 bytes into the buffer, resulting in a 256-byte
heap buffer overflow.

Widen valuesize from u8 to u32 to accommodate the full range.

Fixes: c5c77ba18ea6 ("staging: wilc1000: Add SDIO/SPI 802.11 driver")
Cc: stable@vger.kernel.org
Signed-off-by: Yasuaki Torimaru <yasuakitorimaru@gmail.com>
Link: https://patch.msgid.link/20260324100624.983458-1-yasuakitorimaru@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/wireless/microchip/wilc1000/hif.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/wireless/microchip/wilc1000/hif.c
+++ b/drivers/net/wireless/microchip/wilc1000/hif.c
@@ -162,7 +162,7 @@ int wilc_scan(struct wilc_vif *vif, u8 s
u32 index = 0;
u32 i, scan_timeout;
u8 *buffer;
- u8 valuesize = 0;
+ u32 valuesize = 0;
u8 *search_ssid_vals = NULL;
struct host_if_drv *hif_drv = vif->hif_drv;