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From: Igor Cudnik <igor@its.rel.pl>
To: gregkh@linuxfoundation.org
Cc: heikki.krogerus@linux.intel.com, mika.westerberg@linux.intel.com,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	Igor Cudnik <igor@its.rel.pl>
Subject: [PATCH 1/1] usb: acpi: fix undefined behavior in USB_ACPI_LOCATION_VALID
Date: Tue, 26 May 2026 19:43:37 +0200	[thread overview]
Message-ID: <20260526174513.15692-1-igor@its.rel.pl> (raw)

USB_ACPI_LOCATION_VALID uses a signed left shift into the sign
bit. Shifting a signed value into the sign bit is undefined behavior.
Use BIT(31) instead.

Found by cppcheck:
      drivers/usb/core/usb-acpi.c:221:24: error:
      Shifting signed 32-bit value by 31 bits is undefined behaviour
      [shiftTooManyBitsSigned]

Fixes: f3ac348e6e045 ("usb: usb-acpi: Set port connect type of not connectable ports correctly")
Signed-off-by: Igor Cudnik <igor@its.rel.pl>
---
 drivers/usb/core/usb-acpi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/core/usb-acpi.c b/drivers/usb/core/usb-acpi.c
index 489dbdc96f94..583aca6d7669 100644
--- a/drivers/usb/core/usb-acpi.c
+++ b/drivers/usb/core/usb-acpi.c
@@ -197,7 +197,7 @@ static int usb_acpi_add_usb4_devlink(struct usb_device *udev)
  * Private to usb-acpi, all the core needs to know is that
  * port_dev->location is non-zero when it has been set by the firmware.
  */
-#define USB_ACPI_LOCATION_VALID (1 << 31)
+#define USB_ACPI_LOCATION_VALID BIT(31)
 
 static void
 usb_acpi_get_connect_type(struct usb_port *port_dev, acpi_handle *handle)
-- 
2.53.0


             reply	other threads:[~2026-05-26 18:26 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-26 17:43 Igor Cudnik [this message]
2026-05-27  8:01 ` [PATCH 1/1] usb: acpi: fix undefined behavior in USB_ACPI_LOCATION_VALID Greg KH

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