Findings

CVE-2026-23253

In the Linux kernel, the following vulnerability has been resolved: media: dvb-core: fix wrong reinitialization of ringbuffer on reopen dvb_dvr_open() calls dvb_ringbu…

Published Mar 18, 2026 · updated Oct 15, 2026 · linux linux kernel

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

Timeline

Detection, updates, and resolution for this record.

  1. Mar 18, 2026 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: media: dvb-core: fix wrong reinitialization of ringbuffer on reopen dvb_dvr_open() calls dvb_ringbuffer_init() when a new reader opens the DVR device. dvb_ringbuffer_init() calls init_waitqueue_head(), which reinitializes the waitqueue list head to empty. Since dmxdev->dvr_buffer.queue is a shared waitqueue (all opens of the same

  2. Oct 15, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: media: dvb-core: fix wrong reinitialization of ringbuffer on reopen dvb_dvr_open() calls dvb_ringbuffer_init() when a new reader opens the DVR device. dvb_ringbuffer_init() calls init_waitqueue_head(), which reinitializes the waitqueue list head to empty. Since dmxdev->dvr_buffer.queue is a shared waitqueue (all opens of the same

Affected

  • cpe linux/linux kernelversion unspecified
  • cpe linux/linux kernel7.0

Sources

  • CVE.orgCVE-2026-23253

    Official CVE identifier

    cve.org
  • NIST NVDCVE-2026-23253

    In the Linux kernel, the following vulnerability has been resolved: media: dvb-core: fix wrong reinitialization of ringbuffer on reopen dvb_dvr_open() calls dvb_ringbuffer_init() when a new reader opens the DVR device. dvb_ringbuffer_init() calls init_waitqueue_head(), which r

    nvd.nist.gov

References

CVE-2026-23253 · ZeroDay Findings