Messages in this thread | ![/](/images/icornerl.gif) | | Date | Thu, 9 Dec 2021 14:44:19 +0100 | From | Michal Koutný <> | Subject | Re: [PATCH] exit: Retain nsproxy for exit_task_work() work entries |
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On Wed, Dec 08, 2021 at 01:07:54PM -1000, Tejun Heo <tj@kernel.org> wrote:
> + saved_cred = override_creds(of->file->f_cred); > ret = cgroup_attach_permissions(src_cgrp, dst_cgrp, > - of->file->f_path.dentry->d_sb, threadgroup); > + of->file->f_path.dentry->d_sb, > + threadgroup, ctx->ns); > + revert_creds(saved_cred);
I wonder now whether such a wrap shouldn't also be around cgroup_kill() too (+ replacement of send_sig() with group_send_sig_info() [1])?
This shouldn't break the use case of passing cgroup kill fd to a less privileged task for (auto)destruction purposes but on the other hand it would prevent subverting the fd to a more privileged confused task to kill otherwise disallowed processes.
Thanks, Michal
[1] https://lore.kernel.org/r/m1v97x6niq.fsf@fess.ebiederm.org/
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