{"id":"AZL-86157","summary":"CVE-2026-43319 affecting package kernel for versions less than 6.6.142.1-1","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(&spidev-\u003ebuf_lock)\n  spidev_sync_write() -\u003e mutex_lock(&spidev-\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.","modified":"2026-08-31T05:26:27Z","published":"2026-05-08T14:16:40Z","upstream":["CVE-2026-43319"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43319"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.142.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-86157.json"}}],"schema_version":"1.9.0"}