FKIE_CVE-2026-23381

Vulnerability from fkie_nvd - Published: 2026-03-25 11:16 - Updated: 2026-03-25 15:41
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never initialized because inet6_init() exits before ndisc_init() is called which initializes it. Then, if neigh_suppress is enabled and an ICMPv6 Neighbor Discovery packet reaches the bridge, br_do_suppress_nd() will dereference ipv6_stub->nd_tbl which is NULL, passing it to neigh_lookup(). This causes a kernel NULL pointer dereference. BUG: kernel NULL pointer dereference, address: 0000000000000268 Oops: 0000 [#1] PREEMPT SMP NOPTI [...] RIP: 0010:neigh_lookup+0x16/0xe0 [...] Call Trace: <IRQ> ? neigh_lookup+0x16/0xe0 br_do_suppress_nd+0x160/0x290 [bridge] br_handle_frame_finish+0x500/0x620 [bridge] br_handle_frame+0x353/0x440 [bridge] __netif_receive_skb_core.constprop.0+0x298/0x1110 __netif_receive_skb_one_core+0x3d/0xa0 process_backlog+0xa0/0x140 __napi_poll+0x2c/0x170 net_rx_action+0x2c4/0x3a0 handle_softirqs+0xd0/0x270 do_softirq+0x3f/0x60 Fix this by replacing IS_ENABLED(IPV6) call with ipv6_mod_enabled() in the callers. This is in essence disabling NS/NA suppression when IPv6 is disabled.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/20ef5c25422f97dd09d751e5ae6c18406cdc78e6
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/33dec6f10777d5a8f71c0a200f690da5ae3c2e55
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7a894eb5de246d79f13105c55a67381039a24d44
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a12cdaa3375f0bd3c8f4e564be7c143529abfe5b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/aa73deb3b6b730ec280d45b3f423bfa9e17bc122
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e5e890630533bdc15b26a34bb8e7ef539bdf1322
Impacted products
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: fix nd_tbl NULL dereference when IPv6 is disabled\n\nWhen booting with the \u0027ipv6.disable=1\u0027 parameter, the nd_tbl is never\ninitialized because inet6_init() exits before ndisc_init() is called\nwhich initializes it. Then, if neigh_suppress is enabled and an ICMPv6\nNeighbor Discovery packet reaches the bridge, br_do_suppress_nd() will\ndereference ipv6_stub-\u003end_tbl which is NULL, passing it to\nneigh_lookup(). This causes a kernel NULL pointer dereference.\n\n BUG: kernel NULL pointer dereference, address: 0000000000000268\n Oops: 0000 [#1] PREEMPT SMP NOPTI\n [...]\n RIP: 0010:neigh_lookup+0x16/0xe0\n [...]\n Call Trace:\n  \u003cIRQ\u003e\n  ? neigh_lookup+0x16/0xe0\n  br_do_suppress_nd+0x160/0x290 [bridge]\n  br_handle_frame_finish+0x500/0x620 [bridge]\n  br_handle_frame+0x353/0x440 [bridge]\n  __netif_receive_skb_core.constprop.0+0x298/0x1110\n  __netif_receive_skb_one_core+0x3d/0xa0\n  process_backlog+0xa0/0x140\n  __napi_poll+0x2c/0x170\n  net_rx_action+0x2c4/0x3a0\n  handle_softirqs+0xd0/0x270\n  do_softirq+0x3f/0x60\n\nFix this by replacing IS_ENABLED(IPV6) call with ipv6_mod_enabled() in\nthe callers. This is in essence disabling NS/NA suppression when IPv6 is\ndisabled."
    }
  ],
  "id": "CVE-2026-23381",
  "lastModified": "2026-03-25T15:41:33.977",
  "metrics": {},
  "published": "2026-03-25T11:16:38.160",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/20ef5c25422f97dd09d751e5ae6c18406cdc78e6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/33dec6f10777d5a8f71c0a200f690da5ae3c2e55"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7a894eb5de246d79f13105c55a67381039a24d44"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a12cdaa3375f0bd3c8f4e564be7c143529abfe5b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/aa73deb3b6b730ec280d45b3f423bfa9e17bc122"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e5e890630533bdc15b26a34bb8e7ef539bdf1322"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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