{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-47515", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-24T15:02:54.824Z", "datePublished": "2024-05-24T15:09:29.334Z", "dateUpdated": "2026-05-23T15:20:08.595Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-23T15:20:08.595Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nseg6: fix the iif in the IPv6 socket control block\n\nWhen an IPv4 packet is received, the ip_rcv_core(...) sets the receiving\ninterface index into the IPv4 socket control block (v5.16-rc4,\nnet/ipv4/ip_input.c line 510):\n\n IPCB(skb)->iif = skb->skb_iif;\n\nIf that IPv4 packet is meant to be encapsulated in an outer IPv6+SRH\nheader, the seg6_do_srh_encap(...) performs the required encapsulation.\nIn this case, the seg6_do_srh_encap function clears the IPv6 socket control\nblock (v5.16-rc4 net/ipv6/seg6_iptunnel.c line 163):\n\n memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));\n\nThe memset(...) was introduced in commit ef489749aae5 (\"ipv6: sr: clear\nIP6CB(skb) on SRH ip4ip6 encapsulation\") a long time ago (2019-01-29).\n\nSince the IPv6 socket control block and the IPv4 socket control block share\nthe same memory area (skb->cb), the receiving interface index info is lost\n(IP6CB(skb)->iif is set to zero).\n\nAs a side effect, that condition triggers a NULL pointer dereference if\ncommit 0857d6f8c759 (\"ipv6: When forwarding count rx stats on the orig\nnetdev\") is applied.\n\nTo fix that issue, we set the IP6CB(skb)->iif with the index of the\nreceiving interface once again." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/seg6_iptunnel.c" ], "versions": [ { "version": "c630ec8bdadae9d557b1ceb9d6c06e149108a0d4", "lessThan": "b16d412e5f79734033df04e97d7ea2f50a8e9fe3", "status": "affected", "versionType": "git" }, { "version": "2f704348c93ff8119e642dae6a72327f90b82810", "lessThan": "6431e71093f3da586a00c6d931481ffb0dc2db0e", "status": "affected", "versionType": "git" }, { "version": "ef489749aae508e6f17886775c075f12ff919fb1", "lessThan": "ef8804e47c0a44ae106ead1740408af5ea6c6ee9", "status": "affected", "versionType": "git" }, { "version": "ef489749aae508e6f17886775c075f12ff919fb1", "lessThan": "666521b3852d2b2f52d570f9122b1e4b50d96831", "status": "affected", "versionType": "git" }, { "version": "ef489749aae508e6f17886775c075f12ff919fb1", "lessThan": "98adb2bbfa407c9290bda299d4c6f7a1c4ebd5e1", "status": "affected", "versionType": "git" }, { "version": "ef489749aae508e6f17886775c075f12ff919fb1", "lessThan": "ae68d93354e5bf5191ee673982251864ea24dd5c", "status": "affected", "versionType": "git" }, { "version": "b71b7e0280f47b4ac633fbfd153423814ea87810", "status": "affected", "versionType": "git" }, { "version": "4.14.98", "lessThan": "4.14.258", "status": "affected", "versionType": "semver" }, { "version": "4.19.20", "lessThan": "4.19.221", "status": "affected", "versionType": "semver" }, { "version": "4.20.7", "lessThan": "4.21", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/seg6_iptunnel.c" ], "versions": [ { "version": "5.0", "status": "affected" }, { "version": "0", "lessThan": "5.0", "status": "unaffected", "versionType": "semver" }, { "version": "4.14.258", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.221", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.165", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.85", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.8", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.16", "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": "4.14.98", "versionEndExcluding": "4.14.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19.20", "versionEndExcluding": "4.19.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "5.4.165" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "5.10.85" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "5.15.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "5.16" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20.7" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/b16d412e5f79734033df04e97d7ea2f50a8e9fe3" }, { "url": "https://git.kernel.org/stable/c/6431e71093f3da586a00c6d931481ffb0dc2db0e" }, { "url": "https://git.kernel.org/stable/c/ef8804e47c0a44ae106ead1740408af5ea6c6ee9" }, { "url": "https://git.kernel.org/stable/c/666521b3852d2b2f52d570f9122b1e4b50d96831" }, { "url": "https://git.kernel.org/stable/c/98adb2bbfa407c9290bda299d4c6f7a1c4ebd5e1" }, { "url": "https://git.kernel.org/stable/c/ae68d93354e5bf5191ee673982251864ea24dd5c" } ], "title": "seg6: fix the iif in the IPv6 socket control block", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:39:59.755Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/b16d412e5f79734033df04e97d7ea2f50a8e9fe3", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/6431e71093f3da586a00c6d931481ffb0dc2db0e", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/ef8804e47c0a44ae106ead1740408af5ea6c6ee9", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/666521b3852d2b2f52d570f9122b1e4b50d96831", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/98adb2bbfa407c9290bda299d4c6f7a1c4ebd5e1", "tags": [ "x_transferred" ] }, { "url": 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