Re: [PATCH] printk: Add kernel parameter to disable writes to /dev/kmsg

From: Borislav Petkov
Date: Mon Apr 25 2016 - 14:32:58 EST


On Mon, Apr 25, 2016 at 01:08:53PM -0400, Steven Rostedt wrote:
> [ Sorry for the resend, I forgot to add "[PATCH]" to the subject, which
> may make this fail filters. ]
>
> Over the weekend my server was acting funny. The display wasn't working
> well, and I assumed that a driver was going bad. I went to look at the
> kernel dmesg, but the buffer only had the following over and over:

...

> + disable_devkmsg_write
> + Disable writing to /dev/kmsg. This prevents user space
> + tools from writing into the kernel printk buffers.
> + When set, opening /dev/kmsg for write mode will return
> + -EPERM.

I like the general idea.

Perhaps can call that param "printk.disable_devkmsg" or so with the
proper namespace and in light of printk.always_kmsg_dump=...

Anyway, just my 2Â.

Thanks.

--
Regards/Gruss,
Boris.

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