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ip6_gre: Use cached t->net in ip6erspan_changelink().

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: ip6_gre: Use cached t->net in ip6erspan_changelink(). After commit 5e72ce3e3980 ("net: ipv6: Use link netns in newlink() of rtnl_link_ops"), ip6erspan_newlink() correctly resolves the per-netns ip6gre hash via link_net. ip6erspan_changelink() was not converted in that series and still uses dev_net(dev), which diverges from the device's creation netns after IFLA_NET_NS_FD migration. This re-inserts the tunnel into the wrong per-netns hash. The original netns keeps a stale entry. When that netns is later destroyed, ip6gre_exit_rtnl_net() walks the stale entry, producing a slab-use-after-free reported by KASAN, followed by a kernel BUG at net/core/dev.c (LIST_POISON1) in unregister_netdevice_many_notify(). Reachable from an unprivileged user namespace (unshare --user --map-root-user --net). ip6gre_changelink() earlier in the same file already uses the cached t->net; only ip6erspan_changelink() has the wrong shape.

Announced Source revision 1
Original source ↗

CVE-2026-46120

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-46120

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "2d665034f239412927b1e71329f20f001c92da09",
        "lessThan": "7bd0f2b162b426b343a114e1b329f0d8d14fdc6e",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "2d665034f239412927b1e71329f20f001c92da09",
        "lessThan": "01b71ff2857d3598337de11e7840a8e3ff21553c",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "2d665034f239412927b1e71329f20f001c92da09",
        "lessThan": "0fcf6731706f73494245a9c0d64f93bebf95bb51",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "2d665034f239412927b1e71329f20f001c92da09",
        "lessThan": "eca62bb0569de4d43a4dac06a2092a9d4ca1d702",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "2d665034f239412927b1e71329f20f001c92da09",
        "lessThan": "311fdd26eb4443d43b909cc67a10f3a5fd1b21b2",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "2d665034f239412927b1e71329f20f001c92da09",
        "lessThan": "e70cfb40c3a99b232cd42c6a6a10f0d8e039dc82",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "2d665034f239412927b1e71329f20f001c92da09",
        "lessThan": "cf7fc624329e76c6394653d12353e1d033adea91",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "2d665034f239412927b1e71329f20f001c92da09",
        "lessThan": "1d324c2f43f70c965f25c58cc3611c779adbe47e",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c6d72628352c949629af619b77b042e0fb5245e7",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "4.16.12",
        "lessThan": "4.17",
        "versionType": "semver"
      }
    ],
    "programFiles": [
      "net/ipv6/ip6_gre.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "4.17"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "4.17",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.10.258",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.209",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.175",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.140",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.88",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.30",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.0.7",
        "versionType": "semver",
        "lessThanOrEqual": "7.0.*"
      },
      {
        "status": "unaffected",
        "version": "7.1",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "net/ipv6/ip6_gre.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-46120

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#40135 · Revision 1
Added to Heist Feed
Publisher date
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