Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: printer: fix infinite loop in printer_read()
printer_read() uses the same variable for the requested copy size and the number of bytes actually copied to user space. copy_to_user() returns the number of bytes not copied, so when it fails to copy anything, the computed copied length becomes zero.
In that case len, buf, current_rx_bytes and current_rx_buf are left unchanged. If RX data is available and the user buffer remains unwritable, the read loop can repeat indefinitely.
Track the copied length separately and return -EFAULT, or the number of bytes already copied, if an iteration makes no progress.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 10 ELS , TuxCare 9.6 ESU
- Affected packages:
- kernel @ 4.18.0 (+5 more)