CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's ALSA USB audio subsystem, where an out-of-bounds write can occur due to improper handling of DMA buffer sizes when the fill_max descriptor flag is enabled. This can lead to kernel heap memory corruption, potentially allowing an attacker to execute arbitrary code or crash the system. Organizations using Linux systems that handle USB audio devices should prioritize applying the relevant updates to mitigate this risk.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Fix DMA buffer out-of-bounds write when fill_max is set When a USB audio endpoint requests full packet transfers via the fill_max descriptor flag, data_ep_set_params() promotes ep->curpacksize to ep->maxpacksize. However, maxsize is left at the original sample-rate derived value. Since u->buffer_size is allocated as maxsize * packets, the resulting DMA buffer is far too small for the requested transfer length. When the USB host controller streams up to curpacksize bytes per packet, it writes past the end of the buffer via DMA, corrupting kernel heap memory. Update maxsize to curpacksize when fill_max is set so that the allocated DMA buffer size matches the actual transfer request size. [ changed to reassign maxsize only when ep->fill_max is set -- tiwai ]