From 8f5ef203abda9dd36b2af473c7b737d544f807bd Mon Sep 17 00:00:00 2001 From: Tristan Madani Date: Fri, 4 Sep 2026 20:58:26 +0000 Subject: [PATCH] ALSA: usbusx2y: validate URB actual_length in interrupt callback i_usx2y_in04_int() processes the interrupt URB data without checking urb->actual_length. A short transfer from a malfunctioning device would cause the handler to process uninitialized heap data from the kmalloc-allocated in04_buf, which is then copied to the mmap-accessible ctl_snapshot[] array. Fix by using kzalloc() for in04_buf to zero-initialize the buffer, and adding an actual_length check to skip processing on short transfers while still resubmitting the URB. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Tristan Madani Link: https://patch.msgid.link/20260904205826.4071119-2-tristmd@gmail.com Signed-off-by: Takashi Iwai --- sound/usb/usx2y/usbusx2y.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/sound/usb/usx2y/usbusx2y.c b/sound/usb/usx2y/usbusx2y.c index 200b708aacd6..108f9bddf9aa 100644 --- a/sound/usb/usx2y/usbusx2y.c +++ b/sound/usb/usx2y/usbusx2y.c @@ -189,6 +189,9 @@ static void i_usx2y_in04_int(struct urb *urb) return; } + if (urb->actual_length < USX2Y_IN04_SIZE) + goto resubmit; + if (us428ctls) { diff = -1; if (us428ctls->ctl_snapshot_last == -2) { @@ -253,6 +256,7 @@ static void i_usx2y_in04_int(struct urb *urb) if (err) dev_err(&urb->dev->dev, "in04_int() usb_submit_urb err=%i\n", err); +resubmit: urb->dev = usx2y->dev; usb_submit_urb(urb, GFP_ATOMIC); } @@ -305,7 +309,7 @@ int usx2y_in04_init(struct usx2ydev *usx2y) goto error; } - usx2y->in04_buf = kmalloc(USX2Y_IN04_SIZE, GFP_KERNEL); + usx2y->in04_buf = kzalloc(USX2Y_IN04_SIZE, GFP_KERNEL); if (!usx2y->in04_buf) { err = -ENOMEM; goto error;