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_ringbuffer_init() when a new reader opens the DVR device. dvb_ringbuffer_init() calls…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.13%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.13% probability · 3th percentile
- CISA KEV
- Not listed
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/32eb8e4adc207ef31bc6e5ae56bab940b0176066Patch
- https://git.kernel.org/stable/c/527cfa8a3486b3555c5c15e2f62be484a11398dcPatch
- https://git.kernel.org/stable/c/af050ab44fa1b1897a940d7d756e512232f5e5dfPatch
- https://git.kernel.org/stable/c/bfbc0b5b32a8f28ce284add619bf226716a59bc0Patch
- https://git.kernel.org/stable/c/cfd94642025e6f71c8f754bdec0800ee95e4f3ddPatch
- https://git.kernel.org/stable/c/d71781bad59b1c9d60d7068004581f9bf19c0c9dPatch
- https://git.kernel.org/stable/c/f1e520ca2e83ece6731af6167c9e5e16931ecba0Patch
- https://git.kernel.org/stable/c/fb378cf89be434ed1f10ab79cc4788fba8ae868dPatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.