{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-98070",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-98070"
  ],
  "published": "2026-09-25T10:24:31Z",
  "summary": "net/rds: acquire RDS_IN_XMIT in rds_tcp_reset_callbacks()",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/rds: acquire RDS_IN_XMIT in rds_tcp_reset_callbacks()\n\nrds_tcp_reset_callbacks() quiesces the transmit path by setting the\npath state to RDS_CONN_RESETTING and then waiting for RDS_IN_XMIT to\nbe sampled clear before swapping the underlying socket and calling\nrds_send_path_reset().\n\nSampling the bit clear is not the same as owning it: rds_send_xmit()\ncan re-acquire RDS_IN_XMIT right after the wait_event() returns.  Its\nstate recheck after taking the lock is a store-buffering pattern (the\nresetter writes the state and reads the bit, the sender writes the\nbit and reads the state) and acquire_in_xmit() is only an acquire\noperation, so on weakly ordered architectures both sides can miss\neach other's write and the transmit path then runs concurrently with\nrds_send_path_reset() rewriting cp_xmit_* state - which is exactly\nwhat the comment above rds_send_path_reset() tells its callers to\nprevent.\n\nTake the lock instead, hold it across the socket swap and\nrds_send_path_reset(), and release it with a wake-up at the end.  The\nlock-ordering constraint documented above the wait still holds: the\nlock is acquired before lock_sock(), so a sender inside tcp_sendmsg()\ncan never be waited on while we hold the socket lock.\n\nTwo details of the old code go away with the same change:\n\n - t_sock is now read only after the lock is acquired.  The old code\n   cached it before waiting; the teardown in rds_conn_shutdown()\n   releases that socket and clears t_sock, so a pointer cached before\n   the wait can be stale by the time the accept path resumes.  Reading\n   it under RDS_IN_XMIT is what makes the exclusion complete once the\n   teardown owns the same lock, which the next patch arranges; until\n   then the teardown still only samples the bit, and the two paths\n   remain as exposed to each other as they are today.\n\n - The old !osock early path called rds_send_path_reset() with no\n   serialization at all.  It now runs under the lock like the normal\n   path.  The conditional RDS_CONN_RESETTING transition of the\n   previous patch happens before the socket check either way: a path\n   found without a socket is either still connecting (its reconnect\n   worker blocked on t_conn_path_lock) and legitimately goes\n   RESETTING -> UP on the new socket, or it has been torn down\n   meanwhile and is dropped.\n\nThe in-function comment describing the old wait-based quiesce is\nrewritten to describe the lock-based one, and the stale block comment\nabove the function (which still described a return value and an\nincomplete list of t_sock writers) is refreshed to name all four\nwriters - the connect, accept, teardown and swap paths - and what\nserializes each of them.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "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": "6.1.189",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-98070"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/670af4e4a4de5e6bb5daee3838485571a0caa5fa"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/830a2e21b200c6b6fdccc63dd3f23932bf7a894b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a05790cb4ff03f797d76906990b148d83f63e7a3"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d184e6dd4b8f3c20c018595fd09795a66b46c8ef"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d625112564c3e980e02504270222b49b82690cee"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/8e4c3b7844c906c7097b4cfedd9dd1f48c9a6a92"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/062d9e008c67289e8e1b221ecdd8f9d60566d012"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/02c5f9dc2efd823e061954d564ce00bacd1bebeb"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-10-03T11:04:09Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 8.1,
      "cvss_v3_severity": "High",
      "scenario": "AV:N - rds_tcp_reset_callbacks() runs when a remote peer's TCP SYN to the RDS/TCP listener is accepted by rds_tcp_accept_one() while the local path already has t_sock set (the duelling-SYN case). The peer's routable TCP connection is what sets off the unsynchronized socket swap and rds_send_path_reset().\nAC:H - The attacker must win a narrow store-buffering race between the resetter's test_bit(RDS_IN_XMIT) and rds_send_xmit()'s acquire_in_xmit()/state recheck, which only fails on weakly ordered CPUs. It also needs a duelling SYN that arrives while the local path is still CONNECTING, which the attacker cannot fully control.\nPR:N - The RDS/TCP listener accepts incoming connections with no authentication. The accept path through rds_tcp_accept_one() into rds_tcp_reset_callbacks() needs only a reachable IP address and TCP port.\nUI:N - No local user action is needed. The reset path runs from the listen socket's data_ready callback and accept worker, and rds_send_xmit() is driven by the send worker or by pongs to peer pings.\nS:U - The corruption stays inside kernel memory under a single security authority. Crossing no VM or hardware isolation boundary.\nC:H - rds_send_path_reset() puts cp_xmit_rm and zeroes the cp_xmit_* offsets while a concurrent rds_send_xmit() still dereferences that rds_message. This is a use-after-free, and a stale osock cached before the wait can be released twice. Reclaiming the freed object could leak kernel memory.\nI:H - The use-after-free of the rds_message and of the stale socket, plus the torn cp_xmit_* transmit state, corrupt kernel heap objects that could be reclaimed and used for controlled writes.\nA:H - A sender using a freed cp_xmit_rm, or a double sock_release() of the stale osock, will oops or panic the kernel."
    }
  }
}