FKIE_CVE-2026-23253

Vulnerability from fkie_nvd - Published: 2026-03-18 18:16 - Updated: 2026-03-25 11:16
Severity ?
Summary
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.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/32eb8e4adc207ef31bc6e5ae56bab940b0176066
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/af050ab44fa1b1897a940d7d756e512232f5e5df
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bfbc0b5b32a8f28ce284add619bf226716a59bc0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cfd94642025e6f71c8f754bdec0800ee95e4f3dd
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d71781bad59b1c9d60d7068004581f9bf19c0c9d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f1e520ca2e83ece6731af6167c9e5e16931ecba0
Impacted products
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: dvb-core: fix wrong reinitialization of ringbuffer on reopen\n\ndvb_dvr_open() calls dvb_ringbuffer_init() when a new reader opens the\nDVR device.  dvb_ringbuffer_init() calls init_waitqueue_head(), which\nreinitializes the waitqueue list head to empty.\n\nSince dmxdev-\u003edvr_buffer.queue is a shared waitqueue (all opens of the\nsame DVR device share it), this orphans any existing waitqueue entries\nfrom io_uring poll or epoll, leaving them with stale prev/next pointers\nwhile the list head is reset to {self, self}.\n\nThe waitqueue and spinlock in dvr_buffer are already properly\ninitialized once in dvb_dmxdev_init().  The open path only needs to\nreset the buffer data pointer, size, and read/write positions.\n\nReplace the dvb_ringbuffer_init() call in dvb_dvr_open() with direct\nassignment of data/size and a call to dvb_ringbuffer_reset(), which\nproperly resets pread, pwrite, and error with correct memory ordering\nwithout touching the waitqueue or spinlock."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nmedia: dvb-core: corrige la reinicializaci\u00f3n incorrecta del b\u00fafer circular al reabrir\n\ndvb_dvr_open() llama a dvb_ringbuffer_init() cuando un nuevo lector abre el dispositivo DVR. dvb_ringbuffer_init() llama a init_waitqueue_head(), lo que reinicializa la cabecera de la lista de la cola de espera a vac\u00eda.\n\nDado que dmxdev-\u0026gt;dvr_buffer.queue es una cola de espera compartida (todas las aperturas del mismo dispositivo DVR la comparten), esto deja hu\u00e9rfanas las entradas existentes de la cola de espera de io_uring poll o epoll, dej\u00e1ndolas con punteros prev/next obsoletos mientras la cabecera de la lista se restablece a {self, self}.\n\nLa cola de espera y el spinlock en dvr_buffer ya est\u00e1n correctamente inicializados una vez en dvb_dmxdev_init(). La ruta de apertura solo necesita restablecer el puntero de datos del b\u00fafer, el tama\u00f1o y las posiciones de lectura/escritura.\n\nReemplace la llamada a dvb_ringbuffer_init() en dvb_dvr_open() con la asignaci\u00f3n directa de datos/tama\u00f1o y una llamada a dvb_ringbuffer_reset(), que restablece correctamente pread, pwrite y error con el ordenamiento de memoria correcto sin tocar la cola de espera o el spinlock."
    }
  ],
  "id": "CVE-2026-23253",
  "lastModified": "2026-03-25T11:16:20.870",
  "metrics": {},
  "published": "2026-03-18T18:16:23.383",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/32eb8e4adc207ef31bc6e5ae56bab940b0176066"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/af050ab44fa1b1897a940d7d756e512232f5e5df"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/bfbc0b5b32a8f28ce284add619bf226716a59bc0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cfd94642025e6f71c8f754bdec0800ee95e4f3dd"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d71781bad59b1c9d60d7068004581f9bf19c0c9d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f1e520ca2e83ece6731af6167c9e5e16931ecba0"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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