GHSA-P22Q-5W3Q-WQPQ
Vulnerability from github – Published: 2026-05-08 15:31 – Updated: 2026-05-15 18:30In 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": [],
"aliases": [
"CVE-2026-43319"
],
"database_specific": {
"cwe_ids": [
"CWE-667"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-08T14:16:40Z",
"severity": "MODERATE"
},
"details": "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 -\u003e spi_lock\n ioctl(): spi_lock -\u003e 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() -\u003e mutex_lock(\u0026spidev-\u003ebuf_lock)\n spidev_sync_write() -\u003e mutex_lock(\u0026spidev-\u003espi_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.",
"id": "GHSA-p22q-5w3q-wqpq",
"modified": "2026-05-15T18:30:30Z",
"published": "2026-05-08T15:31:23Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43319"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/40534d19ed2afb880ecf202dab26a8e7a5808d16"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/41ccfac7d302968a4f32b5f7b012d066c5f5cdf8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e341e18215030af2136836b78508e0d798916df7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f8431b8672231d378b03176fe74c95adfd3522cf"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.