Re: [patch 010/286] kmsg: honor dmesg_restrict sysctl on /dev/kmsg

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, Jun 10, 2013 at 1:47 AM, Christian Kujau <lists@xxxxxxxxxxxxxxx> wrote:
> On Tue, 30 Apr 2013 at 08:15, Kees Cook wrote:
>> > Do we have a way forward?  I like Linus's idea of nuking the
>> > dmesg_restrict feature ;)
>>
>> Please no; this is a feature people depend on.
>>
>> Security checks need to be done at open time. The /dev/kmsg
>> misbehavior associated with this patch was related to the interaction
>> with CAP_SYSLOG, not dmesg_restrict. (The new dmesg fell back to
>> syscalls when it couldn't open /dev/kmsg.)
>
> +1 for some kind of dmesg_restrict feature. Without removing
> read-permission from /dev/kmsg during boot, users can still read from it.
> While this may be useful for a lot of cases (bug reports), dmesg can
> indeed contain sensitive information.
>
> At the moment, CONFIG_SECURITY_DMESG_RESTRICT can be set - but it's only
> covering /proc/kmsg and syslog(), right?

No worries, it's all getting fixed. This is what is currently in linux-next:

http://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/kernel/printk.c?id=a0724f739207ca536bbdcbd3b532fe55310ba7d6

-Kees

>
> Christian.
> --
> BOFH excuse #260:
>
> We're upgrading /dev/null



--
Kees Cook
Chrome OS Security
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]