CVE-2026-80859
fuse: fix missing barrier when checking io-uring readiness
Description
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.
INFO
Published Date :
Sept. 4, 2026, 4:18 p.m.
Last Modified :
Sept. 4, 2026, 4:18 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to the latest stable version.
- Apply the specific patch for fuse: fix missing barrier.
- Ensure proper memory barrier synchronization.
- Test system stability after applying updates.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-80859.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/dd9c835709f4bb3e4256eea7573e4e6e18f956de | |
| https://git.kernel.org/stable/c/edb310bc27f0ad83e7fd558a3caf1a94ca511654 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-80859 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-80859
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-80859 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-80859 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 04, 2026
Action Type Old Value New Value Added Description 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/80xxx/CVE-2026-80859.json">CVE-2026-80859</a> Added Reference https://git.kernel.org/stable/c/dd9c835709f4bb3e4256eea7573e4e6e18f956de Added Reference https://git.kernel.org/stable/c/edb310bc27f0ad83e7fd558a3caf1a94ca511654