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CVE-2026-80859 (GCVE-0-2026-80859)

Vulnerability from cvelistv5 – Published: 2026-09-04 15:55 – Updated: 2026-09-11 09:57
VLAI
Title
fuse: fix missing barrier when checking io-uring readiness
Summary
In the Linux kernel, the following vulnerability has been resolved: fuse: fix missing barrier when checking io-uring readiness fuse_block_alloc() reads fch->initialized and then fch->io_uring. fch->io_uring is set before fch->initialized, ordered by the smp_wmb() in fuse_chan_set_intialized(), but fuse_block_alloc() has no matching read barrier between the two loads. This may lead a CPU to observe fch->initialized=1 but fch->io_uring=0, and skip the check that blocks request allocation until the io-uring queues are ready. This can reintroduce the lock-order inversion deadlock that commit 3393ff964e0f prevents. Add an smp_rmb() barrier to pair with the smp_wmb() in fuse_chan_set_initialized() to prevent this.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 3393ff964e0fa5def66570c54a4612bf9df06b76 , < 8974575898cd7a4c818088f102b2e7a0286d3302 (git)
Affected: 3393ff964e0fa5def66570c54a4612bf9df06b76 , < dd9c835709f4bb3e4256eea7573e4e6e18f956de (git)
Affected: 3393ff964e0fa5def66570c54a4612bf9df06b76 , < edb310bc27f0ad83e7fd558a3caf1a94ca511654 (git)
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Linux Linux Affected: 6.14
Unaffected: 0 , < 6.14 (semver)
Unaffected: 6.18.51 , ≤ 6.18.* (semver)
Unaffected: 7.2.3 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
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{
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          "value": "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-\u003einitialized and then fch-\u003eio_uring.\nfch-\u003eio_uring is set before fch-\u003einitialized, 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-\u003einitialized=1 but fch-\u003eio_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."
        }
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    "datePublished": "2026-09-04T15:55:13.378Z",
    "dateReserved": "2026-08-26T14:34:25.797Z",
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      "cve": "CVE-2026-80859",
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      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-80859",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-80859.json",
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}



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