cve-2021-47515
Vulnerability from cvelistv5
Published
2024-05-24 15:09
Modified
2024-12-19 07:43
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: seg6: fix the iif in the IPv6 socket control block When an IPv4 packet is received, the ip_rcv_core(...) sets the receiving interface index into the IPv4 socket control block (v5.16-rc4, net/ipv4/ip_input.c line 510): IPCB(skb)->iif = skb->skb_iif; If that IPv4 packet is meant to be encapsulated in an outer IPv6+SRH header, the seg6_do_srh_encap(...) performs the required encapsulation. In this case, the seg6_do_srh_encap function clears the IPv6 socket control block (v5.16-rc4 net/ipv6/seg6_iptunnel.c line 163): memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); The memset(...) was introduced in commit ef489749aae5 ("ipv6: sr: clear IP6CB(skb) on SRH ip4ip6 encapsulation") a long time ago (2019-01-29). Since the IPv6 socket control block and the IPv4 socket control block share the same memory area (skb->cb), the receiving interface index info is lost (IP6CB(skb)->iif is set to zero). As a side effect, that condition triggers a NULL pointer dereference if commit 0857d6f8c759 ("ipv6: When forwarding count rx stats on the orig netdev") is applied. To fix that issue, we set the IP6CB(skb)->iif with the index of the receiving interface once again.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6431e71093f3da586a00c6d931481ffb0dc2db0e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/666521b3852d2b2f52d570f9122b1e4b50d96831
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/98adb2bbfa407c9290bda299d4c6f7a1c4ebd5e1
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ae68d93354e5bf5191ee673982251864ea24dd5c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b16d412e5f79734033df04e97d7ea2f50a8e9fe3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ef8804e47c0a44ae106ead1740408af5ea6c6ee9
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/6431e71093f3da586a00c6d931481ffb0dc2db0e
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/666521b3852d2b2f52d570f9122b1e4b50d96831
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/98adb2bbfa407c9290bda299d4c6f7a1c4ebd5e1
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/ae68d93354e5bf5191ee673982251864ea24dd5c
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/b16d412e5f79734033df04e97d7ea2f50a8e9fe3
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/ef8804e47c0a44ae106ead1740408af5ea6c6ee9
Impacted products
Vendor Product Version
Linux Linux Version: c630ec8bdadae9d557b1ceb9d6c06e149108a0d4
Version: 2f704348c93ff8119e642dae6a72327f90b82810
Version: ef489749aae508e6f17886775c075f12ff919fb1
Version: ef489749aae508e6f17886775c075f12ff919fb1
Version: ef489749aae508e6f17886775c075f12ff919fb1
Version: ef489749aae508e6f17886775c075f12ff919fb1
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   Linux Linux Version: 5.0
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\"lessThan\": \"ef8804e47c0a\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"ef489749aae5\", \"lessThan\": \"666521b3852d\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"ef489749aae5\", \"lessThan\": \"98adb2bbfa40\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"ef489749aae5\", \"lessThan\": \"ae68d93354e5\", \"versionType\": \"git\"}], \"programFiles\": [\"net/ipv6/seg6_iptunnel.c\"], \"defaultStatus\": \"unaffected\"}, {\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"5.0\"}, {\"status\": \"unaffected\", \"version\": \"0\", \"lessThan\": \"5.0\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"4.14.258\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"4.14.*\"}, {\"status\": \"unaffected\", \"version\": \"4.19.221\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"4.19.*\"}, {\"status\": \"unaffected\", \"version\": \"5.4.165\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"5.4.*\"}, {\"status\": \"unaffected\", \"version\": \"5.10.85\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"5.10.*\"}, {\"status\": \"unaffected\", \"version\": \"5.15.8\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"5.15.*\"}, {\"status\": \"unaffected\", \"version\": \"5.16\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"*\"}], \"programFiles\": [\"net/ipv6/seg6_iptunnel.c\"], \"defaultStatus\": \"affected\"}], \"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\"}], \"x_generator\": {\"engine\": \"bippy-c8e10e5f6187\"}, \"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)-\u003eiif = skb-\u003eskb_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-\u003ecb), the receiving interface index info is lost\\n(IP6CB(skb)-\u003eiif 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)-\u003eiif with the index of the\\nreceiving interface once again.\"}], \"providerMetadata\": {\"orgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"shortName\": \"Linux\", \"dateUpdated\": \"2024-11-04T11:42:47.073Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2021-47515\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2024-11-04T11:42:47.073Z\", \"dateReserved\": \"2024-05-24T15:02:54.824Z\", \"assignerOrgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"datePublished\": \"2024-05-24T15:09:29.334Z\", \"assignerShortName\": \"Linux\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.1"
    }
  }
}


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