Skip to content
Heist/ feed
High

RDMA/rxe: Reject non-8-byte ATOMIC_WRITE payloads

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Reject non-8-byte ATOMIC_WRITE payloads atomic_write_reply() at drivers/infiniband/sw/rxe/rxe_resp.c unconditionally dereferences 8 bytes at payload_addr(pkt): value = *(u64 *)payload_addr(pkt); check_rkey() previously accepted an ATOMIC_WRITE request with pktlen == resid == 0 because the length validation only compared pktlen against resid. A remote initiator that sets the RETH length to 0 therefore reaches atomic_write_reply() with a zero-byte logical payload, and the responder reads sizeof(u64) bytes from past the logical end of the packet into skb->head tailroom, then writes those 8 bytes into the attacker's MR via rxe_mr_do_atomic_write(). That is a remote disclosure of 4 bytes of kernel tailroom per probe (the other 4 bytes are the packet's own trailing ICRC). IBA oA19-28 defines ATOMIC_WRITE as exactly 8 bytes. Anything else is protocol-invalid. Hoist a strict length check into check_rkey() so the responder never reaches the unchecked dereference, and keep the existing WRITE-family length logic for the normal RDMA WRITE path. Reproduced on mainline with an unmodified rxe driver: a sustained zero-length ATOMIC_WRITE probe repeatedly leaks adjacent skb head-buffer bytes into the attacker's MR, including recognisable kernel strings and partial kernel-direct-map pointer words. With this patch applied the responder rejects the PDU and the MR stays all-zero.

Announced Source revision 1
Original source ↗

CVE-2026-46114

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-2026-46114

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": "034e285f8b99062a0cf29112e1232154a6a44aa5",
        "lessThan": "539cabb7b2d8ba70f55bba91db55faef11c2a6d7",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "034e285f8b99062a0cf29112e1232154a6a44aa5",
        "lessThan": "d415fce3fcde6d7aeea6c25362a395b905811452",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "034e285f8b99062a0cf29112e1232154a6a44aa5",
        "lessThan": "105bf79a23b85cf3a761d18a4f3e10ce88526bc1",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "034e285f8b99062a0cf29112e1232154a6a44aa5",
        "lessThan": "7ec1ed4747f5f99f8b797bb438c5efd36079fad5",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "034e285f8b99062a0cf29112e1232154a6a44aa5",
        "lessThan": "1114c87aa6f195cf07da55a27b2122ae26557b26",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "drivers/infiniband/sw/rxe/rxe_resp.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "6.2"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "6.2",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.6.140",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.88",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.30",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.0.7",
        "versionType": "semver",
        "lessThanOrEqual": "7.0.*"
      },
      {
        "status": "unaffected",
        "version": "7.1",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "drivers/infiniband/sw/rxe/rxe_resp.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-46114

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#40121 · Revision 1
Added to Heist Feed
Publisher date
Read the original announcement