5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andy Shevchenko andriy.shevchenko@linux.intel.com
[ Upstream commit 82fe5107fa3d21d6c3fba091c9dbc50495588630 ]
When creating a device path in the driver the snprintf() takes up to 16 characters long argument along with the additional up to 12 characters for the signed integer (as it can't see the actual limits) and tries to pack this into 16 bytes array. GCC complains about that when build with `make W=1`:
drivers/usb/core/usb.c:705:25: note: ‘snprintf’ output between 3 and 28 bytes into a destination of size 16
Since everything works until now, let's just check for the potential buffer overflow and bail out. It is most likely a never happen situation, but at least it makes GCC happy.
Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Link: https://lore.kernel.org/r/20250321164949.423957-1-andriy.shevchenko@linux.in... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/core/usb.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index c4cd9d46f9e3c..7be4e8f77a5ca 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -704,15 +704,16 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent, dev_set_name(&dev->dev, "usb%d", bus->busnum); root_hub = 1; } else { + int n; + /* match any labeling on the hubs; it's one-based */ if (parent->devpath[0] == '0') { - snprintf(dev->devpath, sizeof dev->devpath, - "%d", port1); + n = snprintf(dev->devpath, sizeof(dev->devpath), "%d", port1); /* Root ports are not counted in route string */ dev->route = 0; } else { - snprintf(dev->devpath, sizeof dev->devpath, - "%s.%d", parent->devpath, port1); + n = snprintf(dev->devpath, sizeof(dev->devpath), "%s.%d", + parent->devpath, port1); /* Route string assumes hubs have less than 16 ports */ if (port1 < 15) dev->route = parent->route + @@ -721,6 +722,11 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent, dev->route = parent->route + (15 << ((parent->level - 1)*4)); } + if (n >= sizeof(dev->devpath)) { + usb_put_hcd(bus_to_hcd(bus)); + usb_put_dev(dev); + return NULL; + }
dev->dev.parent = &parent->dev; dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);