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HighFix available

smb: client: fix missing iov bounds check in parse_posix_sids()

Type: advisorySources: OSV

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix missing iov bounds check in parse_posix_sids() In parse_posix_sids(), sidsbuf_end is calculated using the server-supplied out_len without being validated against the actual length of the received iov (iov_len). If a server provides an inflated out_len, sidsbuf_end will point past the end of the iov. This defeats the bounds guards in posix_info_sid_size(), allowing out-of-bounds reads into adjacent kernel memory. Fix this by rejecting responses where the calculated sidsbuf_end would exceed the received iov boundaries or cause pointer wraparound.

Products
Kernel
Affected versions
Not specified
Fixed versions
6.12.112, 6.18.54, 6.6.158, 7.2.8
CVEs
CVE-2026-98405
Confirmed fixed CVEs
Not specified
Updated in this feed
7 Nov 2026, 01:58 UTC · Revision 1

Source evidence

smb: client: fix missing iov bounds check in parse_posix_sids()

core-osv · Original source

Published 14 Oct 2026, 13:27 UTC

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix missing iov bounds check in parse_posix_sids() In parse_posix_sids(), sidsbuf_end is calculated using the server-supplied out_len without being validated against the actual length of the received iov (iov_len). If a server provides an inflated out_len, sidsbuf_end will point past the end of the iov. This defeats the bounds guards in posix_info_sid_size(), allowing out-of-bounds reads into adjacent kernel memory. Fix this by rejecting responses where the calculated sidsbuf_end would exceed the received iov boundaries or cause pointer wraparound.

osv:CVE-2026-98405

Kernel

Fixed versions: 6.6.158, 6.12.112, 6.18.54, 7.2.8

Complete source record
{
  "id": "1ee49f906fecda4ed8f159cea7071137b622d4b42a37229c9dc3c046817fd557",
  "url": "https://osv.dev/vulnerability/CVE-2026-98405",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "smb: client: fix missing iov bounds check in parse_posix_sids()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: smb: client: fix missing iov bounds check in parse_posix_sids() In parse_posix_sids(), sidsbuf_end is calculated using the server-supplied out_len without being validated against the actual length of the received iov (iov_len). If a server provides an inflated out_len, sidsbuf_end will point past the end of the iov. This defeats the bounds guards in posix_info_sid_size(), allowing out-of-bounds reads into adjacent kernel memory. Fix this by rejecting responses where the calculated sidsbuf_end would exceed the received iov boundaries or cause pointer wraparound.",
    "evidence": "osv:CVE-2026-98405",
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      ],
      "modified": "2026-10-28T02:30:48.852635975Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/2f8ed71aaaba3bc8b19cd9930cc62e63e142b299",
        "https://git.kernel.org/stable/c/b09d092eb24ad0110f16a9b7c1ed5d2a0c1733dc",
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  "source_id": "core-osv",
  "document_id": 517170,
  "published_at": "2026-10-14T13:27:40.589+00:00"
}