From 83f0355cf48e4e69bf6d1b9776650ce2275f8ae8 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Moreira?= Date: Tue, 23 Jun 2026 23:35:31 -0300 Subject: [PATCH] usb: core: devio: validate device and interface before buffer allocation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The proc_ioctl() function currently allocates a buffer using kmalloc() before checking the USB device state and resolving the interface number. If either validation fails, the function must free the buffer and return an error. Move these checks to the top of the function to fail early. This avoids unnecessary memory allocation and deallocation on error paths, removes the nested 'else' structure, and eliminates redundant kfree() calls, making the code cleaner and easier to maintain. Signed-off-by: André Moreira Link: https://patch.msgid.link/20260624023532.63009-1-andrem.33333@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/devio.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index e191934623c7..8329d1c7d1b2 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -2329,6 +2329,13 @@ static int proc_ioctl(struct usb_dev_state *ps, struct usbdevfs_ioctl *ctl) if (!connected(ps)) return -ENODEV; + if (ps->dev->state != USB_STATE_CONFIGURED) + return -EHOSTUNREACH; + + intf = usb_ifnum_to_if(ps->dev, ctl->ifno); + if (!intf) + return -EINVAL; + /* alloc buffer */ size = _IOC_SIZE(ctl->ioctl_code); if (size > 0) { @@ -2345,11 +2352,7 @@ static int proc_ioctl(struct usb_dev_state *ps, struct usbdevfs_ioctl *ctl) } } - if (ps->dev->state != USB_STATE_CONFIGURED) - retval = -EHOSTUNREACH; - else if (!(intf = usb_ifnum_to_if(ps->dev, ctl->ifno))) - retval = -EINVAL; - else switch (ctl->ioctl_code) { + switch (ctl->ioctl_code) { /* disconnect kernel driver from interface */ case USBDEVFS_DISCONNECT: