DEBIAN-CVE-2026-23253

In the Linux kernel, the following vulnerability has been resolved:  media: dvb-core: fix wrong reinitialization of ringbuffer on reopen  dvbdvropen() calls dvbringbufferinit() when a new reader opens the DVR device.  dvbringbufferinit() calls initwaitqueuehead(), which reinitializes the waitqueue list head to empty.  Since dmxdev->dvrbuffer.queue is a shared waitqueue (all opens of the same DVR device share it), this orphans any existing waitqueue entries from iouring poll or epoll, leaving them with stale prev/next pointers while the list head is reset to {self, self}.  The waitqueue and spinlock in dvrbuffer are already properly initialized once in dvbdmxdevinit().  The open path only needs to reset the buffer data pointer, size, and read/write positions.  Replace the dvbringbufferinit() call in dvbdvropen() with direct assignment of data/size and a call to dvbringbuffer_reset(), which properly resets pread, pwrite, and error with correct memory ordering without touching the waitqueue or spinlock.