{"id":"CVE-2026-80859","title":"fuse: fix missing barrier when checking io-uring readiness","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: fix missing barrier when checking io-uring readiness\n\nfuse_block_alloc() reads fch->initialized and then fch->io_uring.\nfch->io_uring is set before fch->initializ…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 3393ff964e0fa5def66570c54a4612bf9df06b76 < 8974575898cd7a4c818088f102b2e7a0286d3302","Linux >= 3393ff964e0fa5def66570c54a4612bf9df06b76 < dd9c835709f4bb3e4256eea7573e4e6e18f956de","Linux >= 3393ff964e0fa5def66570c54a4612bf9df06b76 < edb310bc27f0ad83e7fd558a3caf1a94ca511654","Linux 6.14"],"published":"2026-09-04","updated":"2026-09-11","sourceUpdated":"2026-09-11T09:57:14.427Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80859","references":[{"url":"https://git.kernel.org/stable/c/8974575898cd7a4c818088f102b2e7a0286d3302"},{"url":"https://git.kernel.org/stable/c/dd9c835709f4bb3e4256eea7573e4e6e18f956de"},{"url":"https://git.kernel.org/stable/c/edb310bc27f0ad83e7fd558a3caf1a94ca511654"}],"tags":["cve.org"],"epss":0.00155,"epssPercentile":0.0501,"ingestedAt":"2026-09-11T16:45:47.925Z","slug":"CVE-2026-80859","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nfuse: fix missing barrier when checking io-uring readiness\n\nfuse_block_alloc() reads fch->initialized and then fch->io_uring.\nfch->io_uring is set before fch->initialized, ordered by the smp_wmb()\nin fuse_chan_set_intialized(), but fuse_block_alloc() has no matching\nread barrier between the two loads.\n\nThis may lead a CPU to observe fch->initialized=1 but fch->io_uring=0,\nand skip the check that blocks request allocation until the io-uring\nqueues are ready. This can reintroduce the lock-order inversion deadlock\nthat commit 3393ff964e0f prevents.\n\nAdd an smp_rmb() barrier to pair with the smp_wmb() in\nfuse_chan_set_initialized() to prevent this.\n\n## Affected\n\n- `Linux >= 3393ff964e0fa5def66570c54a4612bf9df06b76 < 8974575898cd7a4c818088f102b2e7a0286d3302`\n- `Linux >= 3393ff964e0fa5def66570c54a4612bf9df06b76 < dd9c835709f4bb3e4256eea7573e4e6e18f956de`\n- `Linux >= 3393ff964e0fa5def66570c54a4612bf9df06b76 < edb310bc27f0ad83e7fd558a3caf1a94ca511654`\n- `Linux 6.14`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}