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CVE-2026-43319

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: spi: spidev: fix lock inversion between spi_lock and buf_lock The spidev driver previously used two mutexes, spi_lock and buf_lock, but acquired them in different orders depending on the code path: write()/read(): buf_lock -> spi_lock ioctl(): spi_lock -> buf_lock This AB-BA locking pattern triggers lockdep warnings and can cause real deadlocks: WARNING: possible circular locking dependency detected spidev_ioctl() -> mutex_lock(&spidev->buf_lock) spidev_sync_write() -> mutex_lock(&spidev->spi_lock) *** DEADLOCK *** The issue is reproducible with a simple userspace program that performs write() and SPI_IOC_WR_MAX_SPEED_HZ ioctl() calls from separate threads on the same spidev file descriptor. Fix this by simplifying the locking model and removing the lock inversion entirely. spidev_sync() no longer performs any locking, and all callers serialize access using spi_lock. buf_lock is removed since its functionality is fully covered by spi_lock, eliminating the possibility of lock ordering issues. This removes the lock inversion and prevents deadlocks without changing userspace ABI or behaviour.

Severity
MEDIUM
CVSS score
5.5 (v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-05-08 14:16:40.480000
Last modified
2026-11-06 16:18:34.723000
View original CVE JSON 
{
  "id": "CVE-2026-43319",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-05-08T14:16:40.480",
  "lastModified": "2026-11-06T16:18:34.723",
  "vulnStatus": "Modified",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nspi: spidev: fix lock inversion between spi_lock and buf_lock\n\nThe spidev driver previously used two mutexes, spi_lock and buf_lock,\nbut acquired them in different orders depending on the code path:\n\n  write()/read(): buf_lock -> spi_lock\n  ioctl():       spi_lock -> buf_lock\n\nThis AB-BA locking pattern triggers lockdep warnings and can\ncause real deadlocks:\n\n  WARNING: possible circular locking dependency detected\n  spidev_ioctl() -> mutex_lock(&spidev->buf_lock)\n  spidev_sync_write() -> mutex_lock(&spidev->spi_lock)\n  *** DEADLOCK ***\n\nThe issue is reproducible with a simple userspace program that\nperforms write() and SPI_IOC_WR_MAX_SPEED_HZ ioctl() calls from\nseparate threads on the same spidev file descriptor.\n\nFix this by simplifying the locking model and removing the lock\ninversion entirely. spidev_sync() no longer performs any locking,\nand all callers serialize access using spi_lock.\n\nbuf_lock is removed since its functionality is fully covered by\nspi_lock, eliminating the possibility of lock ordering issues.\n\nThis removes the lock inversion and prevents deadlocks without\nchanging userspace ABI or behaviour."
    }
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  "metrics": {
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          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
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      "source": "[email protected]",
      "type": "Primary",
      "description": [
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          "value": "CWE-667"
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