wifi: wilc1000: fix u8 overflow in SSID scan buffer size calculation

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>

diff --git a/drivers/net/wireless/microchip/wilc1000/hif.c b/drivers/net/wireless/microchip/wilc1000/hif.c
index f354b11cb91978f2118801998c83bb62be6eea4f..944b2a812b63e528fd0312cbecb108ebecb3f310 100644 (file)
--- a/drivers/net/wireless/microchip/wilc1000/hif.c
+++ b/drivers/net/wireless/microchip/wilc1000/hif.c
@@ -163,7 +163,7 @@ int wilc_scan(struct wilc_vif *vif, u8 scan_source,
        u32 index = 0;
        u32 i, scan_timeout;
        u8 *buffer;
-       u8 valuesize = 0;
+       u32 valuesize = 0;
        u8 *search_ssid_vals = NULL;
        const u8 ch_list_len = request->n_channels;
        struct host_if_drv *hif_drv = vif->hif_drv;