Re: [PATCH net] devlink: Fix crash with CONFIG_NET_NS=n

[Jiri Pirko <jiri@resnulli.us>]

Mon, May 15, 2023 at 06:29:25PM CEST, idosch@nvidia.com wrote:
>'__net_initdata' becomes a no-op with CONFIG_NET_NS=y, but when this
>option is disabled it becomes '__initdata', which means the data can be
>freed after the initialization phase. This annotation is obviously
>incorrect for the devlink net device notifier block which is still
>registered after the initialization phase [1].
>
>Fix this crash by removing the '__net_initdata' annotation.
>
>[1]
>general protection fault, probably for non-canonical address 0xcccccccccccccccc: 0000 [#1] PREEMPT SMP
>CPU: 3 PID: 117 Comm: (udev-worker) Not tainted 6.4.0-rc1-custom-gdf0acdc59b09 #64
>Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc37 04/01/2014
>RIP: 0010:notifier_call_chain+0x58/0xc0
>[...]
>Call Trace:
> <TASK>
> dev_set_mac_address+0x85/0x120
> dev_set_mac_address_user+0x30/0x50
> do_setlink+0x219/0x1270
> rtnl_setlink+0xf7/0x1a0
> rtnetlink_rcv_msg+0x142/0x390
> netlink_rcv_skb+0x58/0x100
> netlink_unicast+0x188/0x270
> netlink_sendmsg+0x214/0x470
> __sys_sendto+0x12f/0x1a0
> __x64_sys_sendto+0x24/0x30
> do_syscall_64+0x38/0x80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
>Fixes: e93c9378e33f ("devlink: change per-devlink netdev notifier to static one")
>Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
>Closes: https://lore.kernel.org/netdev/600ddf9e-589a-2aa0-7b69-a438f833ca10@samsung.com/
>Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
>Signed-off-by: Ido Schimmel <idosch@nvidia.com>

Reviewed-by: Jiri Pirko <jiri@nvidia.com>

Thanks!