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CVE-2026-43216

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: net: Drop the lock in skb_may_tx_timestamp() skb_may_tx_timestamp() may acquire sock::sk_callback_lock. The lock must not be taken in IRQ context, only softirq is okay. A few drivers receive the timestamp via a dedicated interrupt and complete the TX timestamp from that handler. This will lead to a deadlock if the lock is already write-locked on the same CPU. Taking the lock can be avoided. The socket (pointed by the skb) will remain valid until the skb is released. The ->sk_socket and ->file member will be set to NULL once the user closes the socket which may happen before the timestamp arrives. If we happen to observe the pointer while the socket is closing but before the pointer is set to NULL then we may use it because both pointer (and the file's cred member) are RCU freed. Drop the lock. Use READ_ONCE() to obtain the individual pointer. Add a matching WRITE_ONCE() where the pointer are cleared.

Severity
MEDIUM
CVSS score
5.5 (v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-05-06 12:16:41.190000
Last modified
2026-11-06 16:18:28.310000
View original CVE JSON 
{
  "id": "CVE-2026-43216",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-05-06T12:16:41.190",
  "lastModified": "2026-11-06T16:18:28.310",
  "vulnStatus": "Modified",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: Drop the lock in skb_may_tx_timestamp()\n\nskb_may_tx_timestamp() may acquire sock::sk_callback_lock. The lock must\nnot be taken in IRQ context, only softirq is okay. A few drivers receive\nthe timestamp via a dedicated interrupt and complete the TX timestamp\nfrom that handler. This will lead to a deadlock if the lock is already\nwrite-locked on the same CPU.\n\nTaking the lock can be avoided. The socket (pointed by the skb) will\nremain valid until the skb is released. The ->sk_socket and ->file\nmember will be set to NULL once the user closes the socket which may\nhappen before the timestamp arrives.\nIf we happen to observe the pointer while the socket is closing but\nbefore the pointer is set to NULL then we may use it because both\npointer (and the file's cred member) are RCU freed.\n\nDrop the lock. Use READ_ONCE() to obtain the individual pointer. Add a\nmatching WRITE_ONCE() where the pointer are cleared."
    }
  ],
  "affected": [
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        {
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          "programFiles": [
            "include/net/sock.h",
            "net/core/skbuff.c",
            "net/socket.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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      "affectedData": [
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          "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
          "defaultStatus": "unknown",
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        {
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              "lessThan": "*",
              "versionType": "custom",
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    }
  ],
  "metrics": {
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      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
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          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
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        "impactScore": 3.6
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          "role": "CISA Coordinator",
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      "source": "[email protected]",
      "type": "Primary",
      "description": [
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          "lang": "en",
          "value": "CWE-476"
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