CVE-2026-43011 (GCVE-0-2026-43011)

Vulnerability from cvelistv5 – Published: 2026-05-01 14:15 – Updated: 2026-05-03 05:46
VLAI?
Title
net/x25: Fix potential double free of skb
Summary
In the Linux kernel, the following vulnerability has been resolved: net/x25: Fix potential double free of skb When alloc_skb fails in x25_queue_rx_frame it calls kfree_skb(skb) at line 48 and returns 1 (error). This error propagates back through the call chain: x25_queue_rx_frame returns 1 | v x25_state3_machine receives the return value 1 and takes the else branch at line 278, setting queued=0 and returning 0 | v x25_process_rx_frame returns queued=0 | v x25_backlog_rcv at line 452 sees queued=0 and calls kfree_skb(skb) again This would free the same skb twice. Looking at x25_backlog_rcv: net/x25/x25_in.c:x25_backlog_rcv() { ... queued = x25_process_rx_frame(sk, skb); ... if (!queued) kfree_skb(skb); }
Severity ?
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 5d0aa038a90b30c9bedde0c41c1fdcd98ecb16e9 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 3f5e3005984645bf5bd129c6b13149879580b1fb (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < f782dd382203b2a8c4552a628431b7de65a19a7b (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 143d4fa68ae9efb83b0c55b12cc7f0d03732a2b1 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 524371398d8463ea7e101fce2cbf3915645d1730 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < fa1dbc93530b34fab0da9862426fe9c918c74dc0 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < c87dd137c0dad07cc55f98181ff380b0c23d2878 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < d10a26aa4d072320530e6968ef945c8c575edf61 (git)
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    Linux Linux Affected: 2.6.12
Unaffected: 0 , < 2.6.12 (semver)
Unaffected: 5.10.253 , ≤ 5.10.* (semver)
Unaffected: 5.15.203 , ≤ 5.15.* (semver)
Unaffected: 6.1.168 , ≤ 6.1.* (semver)
Unaffected: 6.6.134 , ≤ 6.6.* (semver)
Unaffected: 6.12.81 , ≤ 6.12.* (semver)
Unaffected: 6.18.22 , ≤ 6.18.* (semver)
Unaffected: 6.19.12 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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{
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          "programFiles": [
            "net/x25/x25_in.c"
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/x25: Fix potential double free of skb\n\nWhen alloc_skb fails in x25_queue_rx_frame it calls kfree_skb(skb) at\nline 48 and returns 1 (error).\nThis error propagates back through the call chain:\n\nx25_queue_rx_frame returns 1\n    |\n    v\nx25_state3_machine receives the return value 1 and takes the else\nbranch at line 278, setting queued=0 and returning 0\n    |\n    v\nx25_process_rx_frame returns queued=0\n    |\n    v\nx25_backlog_rcv at line 452 sees queued=0 and calls kfree_skb(skb)\nagain\n\nThis would free the same skb twice. Looking at x25_backlog_rcv:\n\nnet/x25/x25_in.c:x25_backlog_rcv() {\n    ...\n    queued = x25_process_rx_frame(sk, skb);\n    ...\n    if (!queued)\n        kfree_skb(skb);\n}"
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        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        {
          "url": "https://git.kernel.org/stable/c/d10a26aa4d072320530e6968ef945c8c575edf61"
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      "title": "net/x25: Fix potential double free of skb",
      "x_generator": {
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    "dateReserved": "2026-05-01T14:12:55.974Z",
    "dateUpdated": "2026-05-03T05:46:03.430Z",
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      "date": "2026-05-07",
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  }
}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.