From: Jakub Kicinski <kuba@kernel.org>
To: Fernando Fernandez Mancera <fmancera@suse.de>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
davem@davemloft.net, edumazet@google.com, pabeni@redhat.com,
horms@kernel.org, dsahern@kernel.org
Subject: Re: [PATCH 00/10 net-next] Convert CONFIG_IPV6 to built-in and remove stubs
Date: Mon, 9 Mar 2026 07:47:58 -0700 [thread overview]
Message-ID: <20260309074758.0ea95a18@kernel.org> (raw)
In-Reply-To: <20260309022013.5199-1-fmancera@suse.de>
On Mon, 9 Mar 2026 03:19:33 +0100 Fernando Fernandez Mancera wrote:
> Historically, the Linux kernel has supported compiling the IPv6 stack as
> a loadable module. While this made sense in the early days of IPv6
> adoption, modern deployments and distributions overwhelmingly either
> build IPv6 directly into the kernel (CONFIG_IPV6=y) or disable it
> entirely (CONFIG_IPV6=n). The modular IPv6 use-case provides little to
> no practical benefit today.
Have you tested this? Every single VM config we have in CI dies with:
[ 0.774671][ T1] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000187: 0000 [#1] SMP KASAN
[ 0.775165][ T1] KASAN: null-ptr-deref in range [0x0000000000000c38-0x0000000000000c3f]
[ 0.775165][ T1] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 7.0.0-rc2-virtme #1 PREEMPT(full)
[ 0.775165][ T1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 0.775165][ T1] RIP: 0010:ipv6_add_dev+0x32/0x1e0
[ 0.775165][ T1] Code: fb 48 83 ec 08 e8 0e 48 a8 ff 85 c0 0f 84 65 01 00 00 48 8d bb 39 0c 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 54 01 00 00
[ 0.775165][ T1] RSP: 0018:ffa0000000017d10 EFLAGS: 00010216
[ 0.775165][ T1] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000001
[ 0.775165][ T1] RDX: 0000000000000187 RSI: 0000000000000008 RDI: 0000000000000c39
[ 0.775165][ T1] RBP: 0000000000000100 R08: ffffffffa3eed8dc R09: fffffbfff4f10288
[ 0.775165][ T1] R10: fffffbfff4f10289 R11: 0000000000000001 R12: dffffc0000000000
[ 0.775165][ T1] R13: dffffc0000000000 R14: ff11000001f1cc00 R15: ffffffffa8216a90
[ 0.775165][ T1] FS: 0000000000000000(0000) GS:ff1100008707a000(0000) knlGS:0000000000000000
[ 0.775165][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.775165][ T1] CR2: ff11000036a1e000 CR3: 000000003453b001 CR4: 0000000000771ef0
[ 0.775165][ T1] PKRU: 55555554
[ 0.775165][ T1] Call Trace:
[ 0.775165][ T1] <TASK>
[ 0.775165][ T1] addrconf_init+0xa9/0x160
[ 0.775165][ T1] inet6_init+0x287/0x410
[ 0.775165][ T1] do_one_initcall+0xd7/0x4a0
[ 0.775165][ T1] ? trace_event_raw_event_initcall_level+0x210/0x210
[ 0.775165][ T1] ? __kmalloc_noprof+0x2c5/0x730
[ 0.775165][ T1] kernel_init_freeable+0x57d/0x620
[ 0.775165][ T1] ? rest_init+0x200/0x200
[ 0.775165][ T1] kernel_init+0x1e/0x170
[ 0.775165][ T1] ? _raw_spin_unlock_irq+0x33/0x50
[ 0.775165][ T1] ret_from_fork+0x472/0x6b0
[ 0.775165][ T1] ? arch_exit_to_user_mode_prepare.isra.0+0x140/0x140
[ 0.775165][ T1] ? __switch_to+0x538/0xcf0
[ 0.775165][ T1] ? rest_init+0x200/0x200
[ 0.775165][ T1] ret_from_fork_asm+0x11/0x20
[ 0.775165][ T1] </TASK>
[ 0.775165][ T1] Modules linked in:
[ 0.816998][ T1] ---[ end trace 0000000000000000 ]---
[ 0.818082][ T1] RIP: 0010:ipv6_add_dev+0x32/0x1e0
[ 0.819103][ T1] Code: fb 48 83 ec 08 e8 0e 48 a8 ff 85 c0 0f 84 65 01 00 00 48 8d bb 39 0c 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 54 01 00 00
[ 0.822985][ T1] RSP: 0018:ffa0000000017d10 EFLAGS: 00010216
[ 0.824176][ T1] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000001
[ 0.825749][ T1] RDX: 0000000000000187 RSI: 0000000000000008 RDI: 0000000000000c39
[ 0.827317][ T1] RBP: 0000000000000100 R08: ffffffffa3eed8dc R09: fffffbfff4f10288
[ 0.828892][ T1] R10: fffffbfff4f10289 R11: 0000000000000001 R12: dffffc0000000000
[ 0.830460][ T1] R13: dffffc0000000000 R14: ff11000001f1cc00 R15: ffffffffa8216a90
[ 0.832037][ T1] FS: 0000000000000000(0000) GS:ff1100008707a000(0000) knlGS:0000000000000000
[ 0.833800][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.835095][ T1] CR2: ff11000036a1e000 CR3: 000000003453b001 CR4: 0000000000771ef0
[ 0.836670][ T1] PKRU: 55555554
[ 0.837358][ T1] Kernel panic - not syncing: Fatal exception
[ 0.838351][ T1] ---[ end Kernel panic - not syncing: Fatal exception ]---
next prev parent reply other threads:[~2026-03-09 14:48 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-09 2:19 [PATCH 00/10 net-next] Convert CONFIG_IPV6 to built-in and remove stubs Fernando Fernandez Mancera
2026-03-09 2:19 ` [PATCH 01/10 net-next] ipv6: convert CONFIG_IPV6 to built-in only and clean up Kconfigs Fernando Fernandez Mancera
2026-03-09 10:24 ` Krzysztof Kozlowski
2026-03-10 19:40 ` Kolbjørn Barmen
2026-03-10 19:58 ` Arnd Bergmann
2026-03-10 20:35 ` Sabrina Dubroca
2026-03-10 21:18 ` Bjørn Mork
2026-03-10 22:18 ` Arnd Bergmann
2026-03-11 8:21 ` Geert Uytterhoeven
2026-03-09 2:19 ` [PATCH 02/10 net-next] ipv6: replace IS_BUILTIN(CONFIG_IPV6) with IS_ENABLED(CONFIG_IPV6) Fernando Fernandez Mancera
2026-03-09 2:19 ` [PATCH 03/10 net-next] ipv6: remove dynamic ICMPv6 sender registration infrastructure Fernando Fernandez Mancera
2026-03-09 2:19 ` [PATCH 04/10 net-next] ipv6: prepare headers for ipv6_stub removal Fernando Fernandez Mancera
2026-03-09 2:19 ` [PATCH 05/10 net-next] drivers: net: drop ipv6_stub usage and use direct function calls Fernando Fernandez Mancera
2026-03-09 2:19 ` [PATCH 06/10 net-next] ipv4: " Fernando Fernandez Mancera
2026-03-09 2:19 ` [PATCH 07/10 net-next] net: convert remaining ipv6_stub users to " Fernando Fernandez Mancera
2026-03-09 2:19 ` [PATCH 08/10 net-next] bpf: remove ipv6_bpf_stub completely and use " Fernando Fernandez Mancera
2026-03-09 2:19 ` [PATCH 09/10 net-next] ipv6: remove ipv6_stub infrastructure completely Fernando Fernandez Mancera
2026-03-09 2:19 ` [PATCH 10/10 net-next] netfilter: remove nf_ipv6_ops and use direct function calls Fernando Fernandez Mancera
2026-03-09 10:22 ` [PATCH 00/10 net-next] Convert CONFIG_IPV6 to built-in and remove stubs Krzysztof Kozlowski
2026-03-09 10:26 ` Krzysztof Kozlowski
2026-03-09 23:18 ` Jakub Kicinski
2026-03-10 20:02 ` Krzysztof Kozlowski
2026-03-10 21:42 ` Jakub Kicinski
2026-03-10 22:15 ` Fernando Fernandez Mancera
2026-03-09 11:33 ` David Woodhouse
2026-03-09 11:38 ` Fernando Fernandez Mancera
2026-03-09 12:43 ` Krzysztof Kozlowski
2026-03-09 12:58 ` Daniel Borkmann
2026-03-09 13:02 ` Krzysztof Kozlowski
2026-03-09 13:14 ` Fernando Fernandez Mancera
2026-03-16 10:24 ` Lorenzo Stoakes (Oracle)
2026-03-16 10:33 ` Krzysztof Kozlowski
2026-03-16 10:50 ` Lorenzo Stoakes (Oracle)
2026-03-16 10:58 ` Krzysztof Kozlowski
2026-03-16 11:10 ` Vlastimil Babka
2026-03-16 11:17 ` Krzysztof Kozlowski
2026-03-09 13:07 ` Fernando Fernandez Mancera
2026-03-09 14:47 ` Jakub Kicinski [this message]
2026-03-09 15:10 ` Fernando Fernandez Mancera
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