FKIE_CVE-2026-52941

Vulnerability from fkie_nvd - Published: 2026-06-24 08:16 - Updated: 2026-06-24 08:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: net/smc: avoid NULL deref of conn->lnk in smc_msg_event tracepoint The smc_msg_event tracepoint class, shared by smc_tx_sendmsg and smc_rx_recvmsg, unconditionally dereferences smc->conn.lnk: __string(name, smc->conn.lnk->ibname) conn->lnk is only set for SMC-R; for SMC-D it is NULL. Other code on these paths already handles this (e.g. !conn->lnk in SMC_STAT_RMB_TX_SIZE_SMALL()). With the tracepoint enabled, the first sendmsg()/recvmsg() on an SMC-D socket crashes: Oops: general protection fault, probably for non-canonical address KASAN: null-ptr-deref in range [...] RIP: 0010:strlen+0x1e/0xa0 Call Trace: trace_event_raw_event_smc_msg_event (net/smc/smc_tracepoint.h:44) smc_rx_recvmsg (net/smc/smc_rx.c:515) smc_recvmsg (net/smc/af_smc.c:2859) __sys_recvfrom (net/socket.c:2315) __x64_sys_recvfrom (net/socket.c:2326) do_syscall_64 The faulting address 0x3e0 is offsetof(struct smc_link, ibname), confirming the NULL ->lnk deref. Enabling the tracepoint requires root, but the trigger itself is unprivileged: socket(AF_SMC, ...) has no capability check, and SMC-D negotiation needs no admin step on s390 or on x86 with the loopback ISM device loaded. Log an empty device name for SMC-D instead of dereferencing NULL.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/561cf66fa9b6c86dfe4e687d2d1aeaaa6739917f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/68200112534bb2acd1d7117dc2d5c124868d866d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/720c76b930c52cd58f50eb6b10569d03dccc7959
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7bf563badd37cb796df5477d2b78bb64148a1268
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b706d6d76a2a2793fe5ad0fbc2a75b6a460094ef
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d2ea0b8aef8746e147602eac87ca8538f4bc7e66
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/smc/smc_tracepoint.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "68200112534bb2acd1d7117dc2d5c124868d866d",
              "status": "affected",
              "version": "aff3083f10bff7a37eaa2b4e6bc5fb627ddd5f84",
              "versionType": "git"
            },
            {
              "lessThan": "720c76b930c52cd58f50eb6b10569d03dccc7959",
              "status": "affected",
              "version": "aff3083f10bff7a37eaa2b4e6bc5fb627ddd5f84",
              "versionType": "git"
            },
            {
              "lessThan": "b706d6d76a2a2793fe5ad0fbc2a75b6a460094ef",
              "status": "affected",
              "version": "aff3083f10bff7a37eaa2b4e6bc5fb627ddd5f84",
              "versionType": "git"
            },
            {
              "lessThan": "d2ea0b8aef8746e147602eac87ca8538f4bc7e66",
              "status": "affected",
              "version": "aff3083f10bff7a37eaa2b4e6bc5fb627ddd5f84",
              "versionType": "git"
            },
            {
              "lessThan": "561cf66fa9b6c86dfe4e687d2d1aeaaa6739917f",
              "status": "affected",
              "version": "aff3083f10bff7a37eaa2b4e6bc5fb627ddd5f84",
              "versionType": "git"
            },
            {
              "lessThan": "7bf563badd37cb796df5477d2b78bb64148a1268",
              "status": "affected",
              "version": "aff3083f10bff7a37eaa2b4e6bc5fb627ddd5f84",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/smc/smc_tracepoint.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.16"
            },
            {
              "lessThan": "5.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.175",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.142",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.92",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: avoid NULL deref of conn-\u003elnk in smc_msg_event tracepoint\n\nThe smc_msg_event tracepoint class, shared by smc_tx_sendmsg and\nsmc_rx_recvmsg, unconditionally dereferences smc-\u003econn.lnk:\n\n\t__string(name, smc-\u003econn.lnk-\u003eibname)\n\nconn-\u003elnk is only set for SMC-R; for SMC-D it is NULL. Other code on\nthese paths already handles this (e.g. !conn-\u003elnk in\nSMC_STAT_RMB_TX_SIZE_SMALL()). With the tracepoint enabled, the first\nsendmsg()/recvmsg() on an SMC-D socket crashes:\n\n  Oops: general protection fault, probably for non-canonical address\n  KASAN: null-ptr-deref in range [...]\n  RIP: 0010:strlen+0x1e/0xa0\n  Call Trace:\n   trace_event_raw_event_smc_msg_event (net/smc/smc_tracepoint.h:44)\n   smc_rx_recvmsg (net/smc/smc_rx.c:515)\n   smc_recvmsg (net/smc/af_smc.c:2859)\n   __sys_recvfrom (net/socket.c:2315)\n   __x64_sys_recvfrom (net/socket.c:2326)\n   do_syscall_64\n\nThe faulting address 0x3e0 is offsetof(struct smc_link, ibname),\nconfirming the NULL -\u003elnk deref. Enabling the tracepoint requires\nroot, but the trigger itself is unprivileged: socket(AF_SMC, ...) has\nno capability check, and SMC-D negotiation needs no admin step on\ns390 or on x86 with the loopback ISM device loaded.\n\nLog an empty device name for SMC-D instead of dereferencing NULL."
    }
  ],
  "id": "CVE-2026-52941",
  "lastModified": "2026-06-24T08:16:24.380",
  "metrics": {},
  "published": "2026-06-24T08:16:24.380",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/561cf66fa9b6c86dfe4e687d2d1aeaaa6739917f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/68200112534bb2acd1d7117dc2d5c124868d866d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/720c76b930c52cd58f50eb6b10569d03dccc7959"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7bf563badd37cb796df5477d2b78bb64148a1268"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b706d6d76a2a2793fe5ad0fbc2a75b6a460094ef"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d2ea0b8aef8746e147602eac87ca8538f4bc7e66"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}


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