Affected: Alpaquita:23: linux-lts, Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

In the Linux kernel, the following vulnerability has been resolved:

USB: serial: option: fix slab OOB read in interrupt URB callback

The interrupt URB buffer is allocated in setup_port_interrupt_in() based on the endpoint's wMaxPacketSize:

buffer_size = usb_endpoint_maxp(epd); port->interrupt_in_buffer = kmalloc(buffer_size, GFP_KERNEL);

When a USB device declares wMaxPacketSize = 8 on its interrupt IN endpoint, the buffer is allocated from kmalloc-8 cache (exactly 8 bytes).

If the device sends a short packet (actual_length < wMaxPacketSize), the URB completes with status == 0 and the callback proceeds to read:

data[sizeof(struct usb_ctrlrequest)]

which evaluates to data[8], accessing 1 byte beyond the allocated 8-byte buffer. This results in a slab out-of-bounds read.

Fix this by adding the missing bounds check: first verify that the actual length is large enough to contain the struct usb_ctrlrequest header before accessing req_pkt->bRequestType and req_pkt->bRequest, and then verify that there is an additional byte for the modem signal state before reading data[sizeof(struct usb_ctrlrequest)] inside the conditional. Use sizeof(*req_pkt) instead of sizeof(struct usb_ctrlrequest) for consistency.

[ johan: use dev_err(); split signals declaration and initialisation ]

In the Linux kernel, the following vulnerability has been resolved:

USB: serial: option: fix slab OOB read in interrupt URB callback

The interrupt URB buffer is allocated in setup_port_interrupt_in() based on the endpoint's wMaxPacketSize:

buffer_size = usb_endpoint_maxp(epd); port->interrupt_in_buffer = kmalloc(buffer_size, GFP_KERNEL);

When a USB device declares wMaxPacketSize = 8 on its interrupt IN endpoint, the buffer is allocated from kmalloc-8 cache (exactly 8 bytes).

If the device sends a short packet (actual_length < wMaxPacketSize), the URB completes with status == 0 and the callback proceeds to read:

data[sizeof(struct usb_ctrlrequest)]

which evaluates to data[8], accessing 1 byte beyond the allocated 8-byte buffer. This results in a slab out-of-bounds read.

Fix this by adding the missing bounds check: first verify that the actual length is large enough to contain the struct usb_ctrlrequest header before accessing req_pkt->bRequestType and req_pkt->bRequest, and then verify that there is an additional byte for the modem signal state before reading data[sizeof(struct usb_ctrlrequest)] inside the conditional. Use sizeof(*req_pkt) instead of sizeof(struct usb_ctrlrequest) for consistency.

[ johan: use dev_err(); split signals declaration and initialisation ]

kernel-devel-7.2.5-1.1 on GA media

Affected: Ubuntu:Pro:14.04:LTS: linux, Ubuntu:Pro:14.04:LTS: linux-aws, Ubuntu:Pro:14.04:LTS: linux-azure, Ubuntu:Pro:14.04:LTS: linux-lts-xenial, Ubuntu:Pro:16.04:LTS: linux, Ubuntu:Pro:16.04:LTS: linux-aws, Ubuntu:Pro:16.04:LTS: linux-aws-hwe, Ubuntu:Pro:16.04:LTS: linux-azure, Ubuntu:Pro:16.04:LTS: linux-gcp, Ubuntu:Pro:16.04:LTS: linux-hwe and 246 more

In the Linux kernel, the following vulnerability has been resolved: USB: serial: option: fix slab OOB read in interrupt URB callback The interrupt URB buffer is allocated in setup_port_interrupt_in() based on the endpoint's wMaxPacketSize: buffer_size = usb_endpoint_maxp(epd); port->interrupt_in_buffer = kmalloc(buffer_size, GFP_KERNEL); When a USB device declares wMaxPacketSize = 8 on its interrupt IN endpoint, the buffer is allocated from kmalloc-8 cache (exactly 8 bytes). If the device sends a short packet (actual_length < wMaxPacketSize), the URB completes with status == 0 and the callback proceeds to read: data[sizeof(struct usb_ctrlrequest)] which evaluates to data[8], accessing 1 byte beyond the allocated 8-byte buffer. This results in a slab out-of-bounds read. Fix this by adding the missing bounds check: first verify that the actual length is large enough to contain the struct usb_ctrlrequest header before accessing req_pkt->bRequestType and req_pkt->bRequest, and then verify that there is an additional byte for the modem signal state before reading data[sizeof(struct usb_ctrlrequest)] inside the conditional. Use sizeof(*req_pkt) instead of sizeof(struct usb_ctrlrequest) for consistency. [ johan: use dev_err(); split signals declaration and initialisation ]

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Linux Kernel ausnutzen, um Speicherfehler und Kernel-Abstürze beziehungsweise Denial-of-Service-Zustände auszulösen, Speicher außerhalb vorgesehener Grenzen auszulesen sowie in einzelnen Fällen weitere Sicherheitsauswirkungen zu verursachen.