CVEvulnerability

CVE-2026-43319

5.5 MEDIUM Published 2026-05-08 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2026-05-08
Last modified
2026-06-17
Assigner
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS 3.1 ([email protected])
5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-667

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.

Affected configurations

• linux linux kernel (>= 6.2 < 6.12.75) • linux linux kernel (>= 6.13 < 6.18.16) • linux linux kernel (>= 6.19 < 6.19.6) • linux linux kernel 7.0

Related

Weakness · CWE (1)

  • CWE-667 Improper Locking weakness

References