Re: [PATCH 1/2] host/rootfs: remove /proc/kcore bind mounts

Demi Marie Obenour
2025-12-15T18:36:19Z

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On 12/15/25 07:27, Alyssa Ross wrote:
> Neither of these services run as root any more, so they don't have
> access to /proc/kcore any more regardless. (Also we don't have
> /proc/kcore on aarch64 so this previously errored there.)
>
> Fixes: 62590b8 ("host/rootfs: Sandbox crosvm")
> Fixes: ec47d36 ("host/rootfs: Sandbox Cloud Hypervisor")
> Signed-off-by: Alyssa Ross <hi@alyssa.is>
> ---
> .../service/vm-services/template/data/service/vhost-user-gpu/run | 1 -
> host/rootfs/image/usr/bin/run-vmm | 1 -
> 2 files changed, 2 deletions(-)
>
> diff --git a/host/rootfs/image/etc/s6-linux-init/run-image/service/vm-services/template/data/service/vhost-user-gpu/run b/host/rootfs/image/etc/s6-linux-init/run-image/service/vm-services/template/data/service/vhost-user-gpu/run
> index b1f9bac..e063a82 100755
> --- a/host/rootfs/image/etc/s6-linux-init/run-image/service/vm-services/template/data/service/vhost-user-gpu/run
> +++ b/host/rootfs/image/etc/s6-linux-init/run-image/service/vm-services/template/data/service/vhost-user-gpu/run
> @@ -40,7 +40,6 @@ bwrap
> --tmpfs /proc/irq
> --remount-ro /proc/irq
> --ro-bind /dev/null /proc/timer_list
> - --ro-bind /dev/null /proc/kcore
> --ro-bind /dev/null /proc/kallsyms
> --ro-bind /dev/null /proc/sysrq-trigger
> --
> diff --git a/host/rootfs/image/usr/bin/run-vmm b/host/rootfs/image/usr/bin/run-vmm
> index 0640239..e30b14c 100755
> --- a/host/rootfs/image/usr/bin/run-vmm
> +++ b/host/rootfs/image/usr/bin/run-vmm
> @@ -113,7 +113,6 @@ bwrap
> --tmpfs /proc/irq
> --remount-ro /proc/irq
> --ro-bind /dev/null /proc/timer_list
> - --ro-bind /dev/null /proc/kcore
> --ro-bind /dev/null /proc/kallsyms
> --ro-bind /dev/null /proc/sysrq-trigger
> --
>
> base-commit: 6ceeb9b236cc50d2bba90068533ca1b7ff229c8b

/proc/sysrq-trigger and /proc/timer_list can also be dropped,
as they are not accessible to unprivileged users.

With or without that change:

Reviewed-by: Demi Marie Obenour <demiobenour@gmail.com>
--
Sincerely,
Demi Marie Obenour (she/her/hers)

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