CVE-2026-89632 affecting package kernel 6.6.157.1-1
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix use-before-check of ReparseDataLength in reparse_buf_ptr() reparse_buf_ptr() reads buf->ReparseDataLength before checking that count covers the full fixed header: buf = (struct reparse_data_buffer *)((u8 *)io + off); len = sizeof(*buf); /* 8 bytes */ rdlen = le16_to_cpu(buf->ReparseDataLength); /* offset 4, 2 bytes */ if (count < len || count < rdlen + len) /* check comes after */ struct reparse_data_buffer has ReparseDataLength at offset 4. If a server returns OutputCount < 6, the read at offset 4-5 reaches past the end of the received data. The off+count bounds against iov_len were already validated, but that does not protect against count being smaller than sizeof(*buf). Split the check: verify count >= sizeof(*buf) before reading ReparseDataLength, then verify count covers the data region.
- Products
- kernel
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-89632
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 17:42 UTC · Revision 1
Source evidence
CVE-2026-89632 affecting package kernel 6.6.157.1-1
core-osv · Original sourcePublished 11 Sept 2026, 20:19 UTC
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix use-before-check of ReparseDataLength in reparse_buf_ptr() reparse_buf_ptr() reads buf->ReparseDataLength before checking that count covers the full fixed header: buf = (struct reparse_data_buffer *)((u8 *)io + off); len = sizeof(*buf); /* 8 bytes */ rdlen = le16_to_cpu(buf->ReparseDataLength); /* offset 4, 2 bytes */ if (count < len || count < rdlen + len) /* check comes after */ struct reparse_data_buffer has ReparseDataLength at offset 4. If a server returns OutputCount < 6, the read at offset 4-5 reaches past the end of the received data. The off+count bounds against iov_len were already validated, but that does not protect against count being smaller than sizeof(*buf). Split the check: verify count >= sizeof(*buf) before reading ReparseDataLength, then verify count covers the data region.
osv:AZL-100757
kernel
Fixed versions: Not specified
Complete source record
{
"id": "d9b820cc713c32484bc8fcb0dedd84a67793dbc9a9b1059915ee65a8153c815f",
"url": "https://osv.dev/vulnerability/AZL-100757",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2026-89632 affecting package kernel 6.6.157.1-1",
"summary": "In the Linux kernel, the following vulnerability has been resolved: smb: client: fix use-before-check of ReparseDataLength in reparse_buf_ptr() reparse_buf_ptr() reads buf->ReparseDataLength before checking that count covers the full fixed header: buf = (struct reparse_data_buffer *)((u8 *)io + off); len = sizeof(*buf); /* 8 bytes */ rdlen = le16_to_cpu(buf->ReparseDataLength); /* offset 4, 2 bytes */ if (count < len || count < rdlen + len) /* check comes after */ struct reparse_data_buffer has ReparseDataLength at offset 4. If a server returns OutputCount < 6, the read at offset 4-5 reaches past the end of the received data. The off+count bounds against iov_len were already validated, but that does not protect against count being smaller than sizeof(*buf). Split the check: verify count >= sizeof(*buf) before reading ReparseDataLength, then verify count covers the data region.",
"evidence": "osv:AZL-100757",
"products": [
{
"name": {
"value": "kernel",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": []
}
],
"severity": "unknown",
"structured": {
"id": "AZL-100757",
"aliases": [
"AZL-100757"
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"last_affected": "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-100757.json"
}
}
],
"modified": "2026-10-22T05:35:55Z",
"provider": "osv",
"upstream": [
"CVE-2026-89632"
],
"references": [
"https://nvd.nist.gov/vuln/detail/CVE-2026-89632"
]
},
"related_cves": [
{
"value": "CVE-2026-89632",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": null
},
"source_id": "core-osv",
"document_id": 404400,
"published_at": "2026-09-11T20:19:48+00:00"
}