CVE-2026-89711 affecting package kernel for versions less than 6.6.157.1-1
In the Linux kernel, the following vulnerability has been resolved: NFSD: remove flawed WARN_ON_ONCE from nfsd_mode_check The header for commit e75b23f9e323 ("nfsd: check d_can_lookup in fh_verify of directories") details the assumption that justified adding the WARN_ON_ONCE to nfsd_mode_check(), that assumption is invalid (in the case of NFS reexport). When NFSD exports an NFS filesystem it is very possible for nfsd_mode_check() to encounter a @dentry that doesn't have i_op->lookup (see nfs_fhget()'s NFS_ATTR_FATTR_MOUNTPOINT and NFS_ATTR_FATTR_V4_REFERRAL handling, and d_flags_for_inode()). So remove nfsd_mode_check()'s WARN_ON_ONCE(). The nfserr_notdir return on that branch must stay. It guards the subsequent lookup_one_unlocked() -> __lookup_slow() path, which calls inode->i_op->lookup() with no NULL check, so returning nfserr_notdir is what keeps a client LOOKUP into such a @dentry from dereferencing a NULL method pointer.
AZL-100889
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:AZL-100889
kernel
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 6.6.157.1-1
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "6.6.157.1-1"
}
]
}
],
"package": {
"name": "kernel",
"purl": "pkg:rpm/azure-linux/kernel",
"ecosystem": "Azure Linux:3"
},
"database_specific": {
"source": "https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-100889.json"
}
}
]- Related CVEs
- CVE-2026-89711
Source reference:
/upstream
Publisher severity
No explicit severity was provided.
- Event
- #68136 · Revision 1
- Added to Heist Feed
- Publisher date