Re: [PATCH v10 0/7] proc: subset=pid: Relax check of mount visibility

Christian Brauner
2026-04-27T15:54:48Z

On Mon, 27 Apr 2026 10:26:01 +0200, Alexey Gladkov wrote:
> When mounting procfs with the subset=pids option, all static files become
> unavailable and only the dynamic part with information about pids is accessible.
>
> In this case, there is no point in imposing additional restrictions on the
> visibility of the entire filesystem for the mounter. Everything that can be
> hidden in procfs is already inaccessible.
>
> [...]

Thanks, I think we ended with something that looks quite decent now.

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Applied to the vfs-7.2.procfs branch of the vfs/vfs.git tree.
Patches in the vfs-7.2.procfs branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-7.2.procfs

[1/7] namespace: record fully visible mounts in list
https://git.kernel.org/vfs/vfs/c/18920cc2ade4
[2/7] fs: move SB_I_USERNS_VISIBLE to FS_USERNS_MOUNT_RESTRICTED
https://git.kernel.org/vfs/vfs/c/a09358516cf2
[3/7] sysfs: remove trivial sysfs_get_tree() wrapper
https://git.kernel.org/vfs/vfs/c/630dc69a9f7d
[4/7] proc: subset=pid: Show /proc/self/net only for CAP_NET_ADMIN
https://git.kernel.org/vfs/vfs/c/0ff06ac76088
[5/7] proc: prevent reconfiguring subset=pid
https://git.kernel.org/vfs/vfs/c/87341f4e3436
[6/7] proc: handle subset=pid separately in userns visibility checks
https://git.kernel.org/vfs/vfs/c/6691ea02bddb
[7/7] docs: proc: add documentation about mount restrictions