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| author | Maoyi Xie <maoyixie.tju@gmail.com> | 2026-06-18 14:19:48 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-07-10 15:14:20 +0200 |
| commit | dd9483726d0f16c1a56879c3edb65128259a4e2b (patch) | |
| tree | 0da86cc2200ea20b59820e633da8f3cf6b565e26 | |
| parent | 7a0d4f60da261f61dcb50c8e05fa53cc7d4d4427 (diff) | |
| download | linux-next-dd9483726d0f16c1a56879c3edb65128259a4e2b.tar.gz linux-next-dd9483726d0f16c1a56879c3edb65128259a4e2b.zip | |
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 <maoyixie.tju@gmail.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Link: https://patch.msgid.link/178176358875.3352358.6059116660356914900@maoyixie.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/misc/usb-ljca.c | 3 |
1 files changed, 3 insertions, 0 deletions
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) |