{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-52939",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2026-52939"
  ],
  "published": "2026-06-24T07:13:41Z",
  "summary": "net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion\n\nrds_ib_xmit_atomic() always programs a masked atomic opcode\n(IB_WR_MASKED_ATOMIC_CMP_AND_SWP or IB_WR_MASKED_ATOMIC_FETCH_AND_ADD)\nfor every RDS atomic cmsg.  But the completion-side switch in\nrds_ib_send_unmap_op() only handles the non-masked opcodes, so a masked\natomic completion falls through to default and returns rm == NULL while\nsend->s_op is left set.  rds_ib_send_cqe_handler() then dereferences the\nNULL rm via rm->m_final_op, oopsing in softirq context.  An unprivileged\nAF_RDS sendmsg() of an atomic cmsg over an active RDS/IB connection\ntriggers it; on hardware that natively accepts masked atomics (mlx4,\nmlx5) no extra setup is needed.\n\n  RDS/IB: rds_ib_send_unmap_op: unexpected opcode 0xd in WR!\n  Oops: general protection fault [#1] SMP KASAN\n  KASAN: null-ptr-deref in range [0x0000000000000190-0x0000000000000197]\n  RIP: rds_ib_send_cqe_handler+0x25c/0xb10 (net/rds/ib_send.c:282)\n  Call Trace:\n   <IRQ>\n   rds_ib_send_cqe_handler (net/rds/ib_send.c:282)\n   poll_scq (net/rds/ib_cm.c:274)\n   rds_ib_tasklet_fn_send (net/rds/ib_cm.c:294)\n   tasklet_action_common (kernel/softirq.c:943)\n   handle_softirqs (kernel/softirq.c:573)\n   run_ksoftirqd (kernel/softirq.c:479)\n   </IRQ>\n  Kernel panic - not syncing: Fatal exception in interrupt\n\nHandle the masked atomic opcodes in the same case as the non-masked\nones: they map to the same struct rds_message.atomic union member, so\nthe existing container_of()/rds_ib_send_unmap_atomic() body is correct\nfor them.",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.176",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-52939"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a0148342badd8c9b2e46551766a27cb76c82e715"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/4dd262f875e87653df50b138de1390ab0628e6b7"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6e4615164d185a26badb2f376a2449f4d174a5f0"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0f22412a2f4fbbe0251c132abee045d15a90e5b6"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0f7baa82a24813cdad0b06a6f8f07e4824af5ed5"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/dcf458120add64c96a6ef5cf719340453f6e6abf"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/4fd34669558085bcb589aa2078a13b0ca79e360d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/34080db3e70ddf94c38512ad2331e3c3afca6cc1"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-06-24T07:13:41Z"
  }
}