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CVE-2026-64577 (GCVE-0-2026-64577)

Vulnerability from cvelistv5 – Published: 2026-08-05 08:09 – Updated: 2026-08-19 16:28
VLAI
Title
gtp: check skb_pull_data() return in gtp1u_send_echo_resp()
Summary
In the Linux kernel, the following vulnerability has been resolved: gtp: check skb_pull_data() return in gtp1u_send_echo_resp() gtp1u_send_echo_resp() ignores skb_pull_data()'s return value. Its caller gtp1u_udp_encap_recv() only guarantees 16 bytes (udphdr + gtp1_header), but the pull requests 20 (gtp1_header_long + udphdr). For a 16-19 byte echo request the pull fails and returns NULL without advancing skb->data; execution continues, and the following skb_push() plus the IP header pushed by iptunnel_xmit() move skb->data below skb->head, tripping skb_under_panic(). Fix it by dropping the packet when skb_pull_data() fails. skbuff: skb_under_panic: ... kernel BUG at net/core/skbuff.c:214! Call Trace: skb_push (net/core/skbuff.c:2648) iptunnel_xmit (net/ipv4/ip_tunnel_core.c:82) gtp_encap_recv (drivers/net/gtp.c:701 drivers/net/gtp.c:808 drivers/net/gtp.c:920) udp_queue_rcv_one_skb (net/ipv4/udp.c:2388) ... Kernel panic - not syncing: Fatal exception in interrupt
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 9af41cc33471ea1efa6f77e188f055cc77d0a5c5 , < 9033fe49926f0e7421fefee922dc086417e905cf (git)
Affected: 9af41cc33471ea1efa6f77e188f055cc77d0a5c5 , < b3c733eaae7f362601c28ac1533d47a961cd3e1c (git)
Affected: 9af41cc33471ea1efa6f77e188f055cc77d0a5c5 , < 4fc7923871d176ce0e5fecf4a9b7bb915af790ed (git)
Affected: 9af41cc33471ea1efa6f77e188f055cc77d0a5c5 , < 961e9b1e33445f8e42859ecc020c9f60d8b69a8b (git)
Affected: 9af41cc33471ea1efa6f77e188f055cc77d0a5c5 , < cf45d748e437b8dd2dd987f27ee79c8c86f95c88 (git)
Affected: 9af41cc33471ea1efa6f77e188f055cc77d0a5c5 , < cd170f051dba9ac146fabcd1b91726487c0cb9fa (git)
guessed Create a notification for this product.
Linux Linux Affected: 5.18
Unaffected: 0 , < 5.18 (semver)
Unaffected: 6.1.183 , ≤ 6.1.* (semver)
Unaffected: 6.6.148 , ≤ 6.6.* (semver)
Unaffected: 6.12.101 , ≤ 6.12.* (semver)
Unaffected: 6.18.42 , ≤ 6.18.* (semver)
Unaffected: 7.1.6 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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          "product": "Linux",
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                  "versionStartIncluding": "5.18",
                  "vulnerable": true
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                  "versionEndExcluding": "6.6.148",
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                  "vulnerable": true
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ngtp: check skb_pull_data() return in gtp1u_send_echo_resp()\n\ngtp1u_send_echo_resp() ignores skb_pull_data()\u0027s return value. Its\ncaller gtp1u_udp_encap_recv() only guarantees 16 bytes (udphdr +\ngtp1_header), but the pull requests 20 (gtp1_header_long + udphdr). For\na 16-19 byte echo request the pull fails and returns NULL without\nadvancing skb-\u003edata; execution continues, and the following skb_push()\nplus the IP header pushed by iptunnel_xmit() move skb-\u003edata below\nskb-\u003ehead, tripping skb_under_panic().\n\nFix it by dropping the packet when skb_pull_data() fails.\n\n  skbuff: skb_under_panic: ...\n  kernel BUG at net/core/skbuff.c:214!\n  Call Trace:\n   skb_push (net/core/skbuff.c:2648)\n   iptunnel_xmit (net/ipv4/ip_tunnel_core.c:82)\n   gtp_encap_recv (drivers/net/gtp.c:701 drivers/net/gtp.c:808 drivers/net/gtp.c:920)\n   udp_queue_rcv_one_skb (net/ipv4/udp.c:2388)\n   ...\n  Kernel panic - not syncing: Fatal exception in interrupt"
        }
      ],
      "metrics": [
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
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              "value": "AV:N - A crafted GTP-U Echo Request to UDP port 2152 reaches gtp_encap_recv \u2192 gtp1u_udp_encap_recv \u2192 gtp1u_send_echo_resp via the in-kernel UDP encap receive path, so a remote IP peer can trigger the bug without local access.\nAC:L - The attacker fully controls the packet: a 16\u201319 byte GTP-U Echo Request with the S flag set and TEID 0 reliably fails the unchecked 20-byte pull and drives the subsequent skb_push path into skb_under_panic with no race or external condition required.\nPR:N - GTP-U echo handling runs on unauthenticated received UDP datagrams once a GTP device with kernel-created sockets exists; the attacker needs no credentials or local privileges on the target.\nUI:N - No victim action is required; packet delivery to the GTP-U encap socket alone invokes the vulnerable echo-response path.\nS:U - Impact is a kernel BUG/panic in the host GTP/network stack within the same security authority; it does not cross a VM, IOMMU, or other separate boundary.\nC:N - The failure is a deterministic skb headroom underflow caught by skb_under_panic/BUG with no out-of-bounds read, UAF, or other information-disclosure primitive identified.\nI:N - skb_push detects data \u003c head and BUG()s before further attacker-controlled writes; this is an availability crash, not an exploitable write or control-flow hijack primitive.\nA:H - The commit-reproduced path hits skb_under_panic and a fatal kernel BUG in interrupt context, causing kernel panic and full denial of service that can be retriggered by further crafted echo requests."
            }
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64577",
    "datePublished": "2026-08-05T08:09:33.135Z",
    "dateReserved": "2026-07-19T15:36:31.798Z",
    "dateUpdated": "2026-08-19T16:28:59.684Z",
    "state": "PUBLISHED"
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      "product_status:fixed": "1",
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      "status": "final",
      "title": "gtp: check skb_pull_data() return in gtp1u_send_echo_resp()",
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For\\na 16-19 byte echo request the pull fails and returns NULL without\\nadvancing skb-\u003edata; execution continues, and the following skb_push()\\nplus the IP header pushed by iptunnel_xmit() move skb-\u003edata below\\nskb-\u003ehead, tripping skb_under_panic().\\n\\nFix it by dropping the packet when skb_pull_data() fails.\\n\\n  skbuff: skb_under_panic: ...\\n  kernel BUG at net/core/skbuff.c:214!\\n  Call Trace:\\n   skb_push (net/core/skbuff.c:2648)\\n   iptunnel_xmit (net/ipv4/ip_tunnel_core.c:82)\\n   gtp_encap_recv (drivers/net/gtp.c:701 drivers/net/gtp.c:808 drivers/net/gtp.c:920)\\n   udp_queue_rcv_one_skb (net/ipv4/udp.c:2388)\\n   ...\\n  Kernel panic - not syncing: Fatal exception in interrupt\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/net/gtp.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"9af41cc33471ea1efa6f77e188f055cc77d0a5c5\",\"lessThan\":\"9033fe49926f0e7421fefee922dc086417e905cf\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"9af41cc33471ea1efa6f77e188f055cc77d0a5c5\",\"lessThan\":\"b3c733eaae7f362601c28ac1533d47a961cd3e1c\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"9af41cc33471ea1efa6f77e188f055cc77d0a5c5\",\"lessThan\":\"4fc7923871d176ce0e5fecf4a9b7bb915af790ed\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"9af41cc33471ea1efa6f77e188f055cc77d0a5c5\",\"lessThan\":\"961e9b1e33445f8e42859ecc020c9f60d8b69a8b\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"9af41cc33471ea1efa6f77e188f055cc77d0a5c5\",\"lessThan\":\"cf45d748e437b8dd2dd987f27ee79c8c86f95c88\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"9af41cc33471ea1efa6f77e188f055cc77d0a5c5\",\"lessThan\":\"cd170f051dba9ac146fabcd1b91726487c0cb9fa\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/net/gtp.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"5.18\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"5.18\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.183\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.148\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.101\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.42\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.6\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/4fc7923871d176ce0e5fecf4a9b7bb915af790ed\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9033fe49926f0e7421fefee922dc086417e905cf\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/961e9b1e33445f8e42859ecc020c9f60d8b69a8b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b3c733eaae7f362601c28ac1533d47a961cd3e1c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/cd170f051dba9ac146fabcd1b91726487c0cb9fa\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/cf45d748e437b8dd2dd987f27ee79c8c86f95c88\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-08T16:34:55+00:00",
      "cve": "CVE-2026-64577",
      "id": "CVE-2026-64577",
      "initial_release_date": "2026-08-05T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: gtp: check skb_pull_data() return in gtp1u_send_echo_resp()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64577.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-09-15T01:45:15Z",
      "cve": "CVE-2026-64577",
      "id": "CVE-2026-64577",
      "initial_release_date": "2026-08-06T01:06:18Z",
      "product_status:first_fixed": "96",
      "product_status:known_affected": "542",
      "product_status:known_not_affected": "193",
      "product_status:recommended": "46",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64577",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64577.json",
      "version": "10"
    }
  }
}



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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.

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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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