{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64577", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.798Z", "datePublished": "2026-08-05T08:09:33.135Z", "dateUpdated": "2026-08-19T16:28:59.684Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:28:59.684Z" }, "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()'s 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->data; execution continues, and the following skb_push()\nplus the IP header pushed by iptunnel_xmit() move skb->data below\nskb->head, 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": [ { "cvssV3_1": { "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" }, "scenarios": [ { "lang": "en", "value": "AV:N - A crafted GTP-U Echo Request to UDP port 2152 reaches gtp_encap_recv → gtp1u_udp_encap_recv → 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 16–19 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 < 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." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/gtp.c" ], "versions": [ { "version": "9af41cc33471ea1efa6f77e188f055cc77d0a5c5", "lessThan": "9033fe49926f0e7421fefee922dc086417e905cf", "status": "affected", "versionType": "git" }, { "version": "9af41cc33471ea1efa6f77e188f055cc77d0a5c5", "lessThan": "b3c733eaae7f362601c28ac1533d47a961cd3e1c", "status": "affected", "versionType": "git" }, { "version": "9af41cc33471ea1efa6f77e188f055cc77d0a5c5", "lessThan": "4fc7923871d176ce0e5fecf4a9b7bb915af790ed", "status": "affected", "versionType": "git" }, { "version": "9af41cc33471ea1efa6f77e188f055cc77d0a5c5", "lessThan": "961e9b1e33445f8e42859ecc020c9f60d8b69a8b", "status": "affected", "versionType": "git" }, { "version": "9af41cc33471ea1efa6f77e188f055cc77d0a5c5", "lessThan": "cf45d748e437b8dd2dd987f27ee79c8c86f95c88", "status": "affected", "versionType": "git" }, { "version": "9af41cc33471ea1efa6f77e188f055cc77d0a5c5", "lessThan": "cd170f051dba9ac146fabcd1b91726487c0cb9fa", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/gtp.c" ], "versions": [ { "version": "5.18", "status": "affected" }, { "version": "0", "lessThan": "5.18", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.148", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.101", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.6.148" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.12.101" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.18.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/9033fe49926f0e7421fefee922dc086417e905cf" }, { "url": "https://git.kernel.org/stable/c/b3c733eaae7f362601c28ac1533d47a961cd3e1c" }, { "url": "https://git.kernel.org/stable/c/4fc7923871d176ce0e5fecf4a9b7bb915af790ed" }, { "url": "https://git.kernel.org/stable/c/961e9b1e33445f8e42859ecc020c9f60d8b69a8b" }, { "url": "https://git.kernel.org/stable/c/cf45d748e437b8dd2dd987f27ee79c8c86f95c88" }, { "url": "https://git.kernel.org/stable/c/cd170f051dba9ac146fabcd1b91726487c0cb9fa" } ], "title": "gtp: check skb_pull_data() return in gtp1u_send_echo_resp()", "x_generator": { "engine": "bippy-1.2.0" } } } }