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Critical

ksmbd: fix signededness bug in smb_direct_prepare_negotiation()

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix signededness bug in smb_direct_prepare_negotiation() smb_direct_prepare_negotiation() casts an unsigned __u32 value from sp->max_recv_size and req->preferred_send_size to a signed int before computing min_t(int, ...). A maliciously provided preferred_send_size of 0x80000000 will return as smaller than max_recv_size, and then be used to set the maximum allowed alowed receive size for the next message. By sending a second message with a large value (>1420 bytes) the attacker can then achieve a heap buffer overflow. This fix replaces min_t(int, ...) with min_t(u32)

Announced Group revision 1
Original source ↗

CVE-2026-43185

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: cve:CVE-2026-43185

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
        "lessThan": "56eab82fa6fb5ca024b0514e249d40d9b23ee5a7",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
        "lessThan": "a110dbe928561d440e9e117d17331139a0bedace",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
        "lessThan": "ceae058eb707ddd0d68f0872f9d9f23b7c30c37b",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
        "lessThan": "55abc475d096da4a5356b6efb0cfdc6156bc1550",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
        "lessThan": "6b4f875aac344cdd52a1f34cc70ed2f874a65757",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "fs/smb/server/transport_rdma.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "5.15"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "5.15",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.6.160",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.114",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.16",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "6.19.6",
        "versionType": "semver",
        "lessThanOrEqual": "6.19.*"
      },
      {
        "status": "unaffected",
        "version": "7.0",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "fs/smb/server/transport_rdma.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-43185

Source reference: /cveMetadata/cveId

Publisher severity

critical

Source reference: /containers/cna/metrics

Event
#46267 · Revision 1
Added to Heist Feed
Publisher date
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