From ae8eecd0dc1f8994064367a50bd00817764c1bad Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Mon, 9 Feb 2026 15:20:48 +0100 Subject: [PATCH] usb: mdc800: handle signal and read racing commit 2d6d260e9a3576256fe9ef6d1f7930c9ec348723 upstream. If a signal arrives after a read has partially completed, we need to return the number of bytes read. -EINTR is correct only if that number is zero. Signed-off-by: Oliver Neukum Cc: stable Link: https://patch.msgid.link/20260209142048.1503791-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/image/mdc800.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/image/mdc800.c b/drivers/usb/image/mdc800.c index fc0e22cc6fda..ab38ad901457 100644 --- a/drivers/usb/image/mdc800.c +++ b/drivers/usb/image/mdc800.c @@ -708,7 +708,7 @@ static ssize_t mdc800_device_read (struct file *file, char __user *buf, size_t l if (signal_pending (current)) { mutex_unlock(&mdc800->io_lock); - return -EINTR; + return len == left ? -EINTR : len-left; } sts=left > (mdc800->out_count-mdc800->out_ptr)?mdc800->out_count-mdc800->out_ptr:left;