7.3High

CVE-2026-98543bpf: fs/xattr: don't assume the inode is locked in path_unlink/path_rmdir

Linux Linux Published: (25 days ago)

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.

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

VendorProductVersions
Linux Linux 6.15
linux linux kernel 6.15 – < 6.18.55

Ubuntu fixes

  • USN-8959-1 Linux kernel vulnerabilities Ubuntu 26.04, 24.04 · 03.11.2026 · linux, linux-aws, linux-gcp, linux-hwe-7.0, linux-ibm, linux-oracle
  • USN-8960-1 Linux kernel (OEM) vulnerabilities Ubuntu 26.04 · 03.11.2026 · linux-oem-7.0

References and patches