From dd9483726d0f16c1a56879c3edb65128259a4e2b Mon Sep 17 00:00:00 2001 From: Maoyi Xie Date: Thu, 18 Jun 2026 14:19:48 +0800 Subject: [PATCH] usb: ljca: bound bank_num in ljca_enumerate_gpio() ljca_enumerate_gpio() reads desc->bank_num from the device and loops valid_pin[i] = get_unaligned_le32(...) for i < bank_num. valid_pin[] holds only LJCA_MAX_GPIO_NUM / 32 = 2 entries. Two checks run before the loop. The reply length must match struct_size(desc, bank_desc, bank_num). The product pins_per_bank * bank_num must not exceed LJCA_MAX_GPIO_NUM. Neither one bounds bank_num against the size of valid_pin[]. The reply is capped at LJCA_MAX_PAYLOAD_SIZE (60) bytes, so the struct_size check limits bank_num to 9. A device that reports bank_num 9 with pins_per_bank 7 still passes both checks. gpio_num is 63 and the reply is 56 bytes. The loop then writes nine u32 into the two entry array and overruns valid_pin[] on the stack. A broken or malicious LJCA device can therefore overflow the stack. Reject a bank_num that does not fit valid_pin[]. Fixes: acd6199f195d ("usb: Add support for Intel LJCA device") Signed-off-by: Maoyi Xie Acked-by: Sakari Ailus Link: https://patch.msgid.link/178176358875.3352358.6059116660356914900@maoyixie.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/misc/usb-ljca.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/misc/usb-ljca.c b/drivers/usb/misc/usb-ljca.c index c60121faa3da..a1876c05b7c2 100644 --- a/drivers/usb/misc/usb-ljca.c +++ b/drivers/usb/misc/usb-ljca.c @@ -596,6 +596,9 @@ static int ljca_enumerate_gpio(struct ljca_adapter *adap) if (gpio_num > LJCA_MAX_GPIO_NUM) return -EINVAL; + if (desc->bank_num > ARRAY_SIZE(valid_pin)) + return -EINVAL; + /* construct platform data */ gpio_info = kzalloc_obj(*gpio_info); if (!gpio_info)