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CVE PROGRAM SOURCE RECORD7.8 High

CVE-2026-46120

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

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • 2d665034f239412927b1e71329f20f001c92da09 to < 7bd0f2b162b426b343a114e1b329f0d8d14fdc6eaffected
  • 2d665034f239412927b1e71329f20f001c92da09 to < 01b71ff2857d3598337de11e7840a8e3ff21553caffected
  • 2d665034f239412927b1e71329f20f001c92da09 to < 0fcf6731706f73494245a9c0d64f93bebf95bb51affected
  • 2d665034f239412927b1e71329f20f001c92da09 to < eca62bb0569de4d43a4dac06a2092a9d4ca1d702affected
  • 2d665034f239412927b1e71329f20f001c92da09 to < 311fdd26eb4443d43b909cc67a10f3a5fd1b21b2affected
  • 2d665034f239412927b1e71329f20f001c92da09 to < e70cfb40c3a99b232cd42c6a6a10f0d8e039dc82affected
  • 2d665034f239412927b1e71329f20f001c92da09 to < cf7fc624329e76c6394653d12353e1d033adea91affected
  • 2d665034f239412927b1e71329f20f001c92da09 to < 1d324c2f43f70c965f25c58cc3611c779adbe47eaffected
  • c6d72628352c949629af619b77b042e0fb5245e7affected
  • 4.16.12 to < 4.17affected

Linux Linux

Default version status: affected

  • 4.17affected
  • 0 to < 4.17unaffected
  • 5.10.258 to ≤ 5.10.*unaffected
  • 5.15.209 to ≤ 5.15.*unaffected
  • 6.1.175 to ≤ 6.1.*unaffected
  • 6.6.140 to ≤ 6.6.*unaffected
  • 6.12.88 to ≤ 6.12.*unaffected
  • 6.18.30 to ≤ 6.18.*unaffected
  • 7.0.7 to ≤ 7.0.*unaffected
  • 7.1 to ≤ *unaffected

References