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.
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.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Wed, 25 Mar 2026 10:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-03-25T10:28:00.416Z
Reserved: 2026-01-13T15:37:46.007Z
Link: CVE-2026-23381
No data.
Status : Received
Published: 2026-03-25T11:16:38.160
Modified: 2026-03-25T11:16:38.160
Link: CVE-2026-23381
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.