{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-53669", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-10-07T15:16:59.663Z", "datePublished": "2025-10-07T15:21:26.896Z", "dateUpdated": "2026-08-05T09:15:25.435Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:15:25.435Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: fix skb_copy_ubufs() vs BIG TCP\n\nDavid Ahern reported crashes in skb_copy_ubufs() caused by TCP tx zerocopy\nusing hugepages, and skb length bigger than ~68 KB.\n\nskb_copy_ubufs() assumed it could copy all payload using up to\nMAX_SKB_FRAGS order-0 pages.\n\nThis assumption broke when BIG TCP was able to put up to 512 KB per skb.\n\nWe did not hit this bug at Google because we use CONFIG_MAX_SKB_FRAGS=45\nand limit gso_max_size to 180000.\n\nA solution is to use higher order pages if needed.\n\nv2: add missing __GFP_COMP, or we leak memory." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable code only runs on locally-originated TX skbs carrying MSG_ZEROCOPY frags; received network packets never carry zcopy frags (skb_zcopy() is false, early return), so a remote peer cannot reach it. Triggering requires local socket/syscall activity.\nAC:L - The local attacker controls every precondition — enabling BIG TCP (CAP_NET_ADMIN via user namespace on a private netns device), using THP/hugepage-backed buffers, and sending MSG_ZEROCOPY payloads sized to overflow — so the overflow is reliably reproducible.\nPR:L - Exploitation requires running local code (MSG_ZEROCOPY sendmsg) and CAP_NET_ADMIN to raise gso_max_size, both available to a basic unprivileged user through an unprivileged user+network namespace. No real root is needed.\nUI:N - The attacker triggers the overflow entirely through its own socket operations; no action by another user is required.\nS:U - The out-of-bounds write corrupts kernel heap within the same kernel security authority; there is no crossing of a VM/IOMMU/sandbox boundary.\nC:H - The OOB write corrupts skb_shared_info frag page descriptors, which can be steered so kernel data is read/transmitted from attacker-influenced pages, and per guidance memory corruption leveragable for disclosure scores High.\nI:H - This is a controllable-size out-of-bounds heap write (frag descriptors written past the frags array), providing a write primitive suitable for control-flow hijacking or privilege escalation.\nA:H - The overflow reliably corrupts adjacent memory and was reported as causing kernel crashes (oops/panic), a full denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/core/skbuff.c" ], "versions": [ { "version": "7c4e983c4f3cf94fcd879730c6caa877e0768a4d", "lessThan": "7fa93e39fbb0566019c388a8038a4d58552e0910", "status": "affected", "versionType": "git" }, { "version": "7c4e983c4f3cf94fcd879730c6caa877e0768a4d", "lessThan": "3c77a377877acbaf03cd7caa21d3644a5dd16301", "status": "affected", "versionType": "git" }, { "version": "7c4e983c4f3cf94fcd879730c6caa877e0768a4d", "lessThan": "9cd62f0ba465cf647c7d8c2ca7b0d99ea0c1328f", "status": "affected", "versionType": "git" }, { "version": "7c4e983c4f3cf94fcd879730c6caa877e0768a4d", "lessThan": "7e692df3933628d974acb9f5b334d2b3e885e2a6", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/core/skbuff.c" ], "versions": [ { "version": "5.19", "status": "affected" }, { "version": "0", "lessThan": "5.19", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.29", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.2.16", "lessThanOrEqual": "6.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.3.3", "lessThanOrEqual": "6.3.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.4", "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": "5.19", "versionEndExcluding": "6.1.29" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.2.16" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.3.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.4" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/7fa93e39fbb0566019c388a8038a4d58552e0910" }, { "url": "https://git.kernel.org/stable/c/3c77a377877acbaf03cd7caa21d3644a5dd16301" }, { "url": "https://git.kernel.org/stable/c/9cd62f0ba465cf647c7d8c2ca7b0d99ea0c1328f" }, { "url": "https://git.kernel.org/stable/c/7e692df3933628d974acb9f5b334d2b3e885e2a6" } ], "title": "tcp: fix skb_copy_ubufs() vs BIG TCP", "x_generator": { "engine": "bippy-1.2.0" } } } }