Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On Fri, 27.02.15 21:14, Nico Kadel-Garcia (nka...@gmail.com) wrote: > > On Wed, Feb 25, 2015 at 9:39 AM, Michal Schmidt wrote: > >> On 02/25/2015 03:04 PM, Josh Boyer wrote: > >>> On Wed, Feb 25, 2015 at 8:54 AM, Ali AlipourR wrote: > >>> Hi, > >>> > >>> Why sysrq is limited to only "sync" command on official fedora kernel? > >> > >> The kernel itself isn't limited. It's just set that way in > >> /usr/lib/sysctl.d/50-default.conf which is provided by systemd. You > >> can edit that file, > > > > The file in /usr will be overwritten by the next package update. > > > >> create your own in /etc/sysctl.d/, > > > > Yes, local configuration belongs to /etc. > > See also "man sysctl.d". > > Except, of course, that it is apparently Leonard Pottering's > announced desire to stop people from using /etc/ Hmm? What? I figure "Leonard Pottering" cannot be a misspelling of my name, given that what you claim his desire to be is certainly not even remotely mine. Plese stop FUDding around! Thank you, Lennart -- Lennart Poettering, Red Hat -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
Am 28.02.2015 um 03:14 schrieb Nico Kadel-Garcia: On Wed, Feb 25, 2015 at 9:39 AM, Michal Schmidt wrote: On 02/25/2015 03:04 PM, Josh Boyer wrote: On Wed, Feb 25, 2015 at 8:54 AM, Ali AlipourR wrote: Hi, Why sysrq is limited to only "sync" command on official fedora kernel? The kernel itself isn't limited. It's just set that way in /usr/lib/sysctl.d/50-default.conf which is provided by systemd. You can edit that file, The file in /usr will be overwritten by the next package update. create your own in /etc/sysctl.d/, Yes, local configuration belongs to /etc. See also "man sysctl.d". Except, of course, that it is apparently Leonard Pottering's announced desire to stop people from using /etc/ stop that trolling *local* CONFIGURATIONS belong to /etc and nothing else Lennarts point is that any defaults and package data don't belong there and he is not completly wrong in that context - in the best case you would have a operating system with *nothing* in /etc and any package shipped stuff can have a *override* file with the same name in /etc at the end this would also obsolete all that rpmnew / rpmsave stuff just because files from packages would no longer be touched by a user but *completly* ignored from the moment there is a replacement in /etc signature.asc Description: OpenPGP digital signature -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On 02/27/2015 06:14 PM, Nico Kadel-Garcia wrote: Except, of course, that it is apparently Leonard Pottering's announced desire to stop people from using /etc/ No, it's not. Why do people insist on misinterpreting him? He wants it to be possible to have a read-only / (including /etc), so *dynamic* information needs to be stored elsewhere. -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
> On Wed, Feb 25, 2015 at 9:39 AM, Michal Schmidt wrote: >> On 02/25/2015 03:04 PM, Josh Boyer wrote: >>> On Wed, Feb 25, 2015 at 8:54 AM, Ali AlipourR wrote: >>> Hi, >>> >>> Why sysrq is limited to only "sync" command on official fedora kernel? >> >> The kernel itself isn't limited. It's just set that way in >> /usr/lib/sysctl.d/50-default.conf which is provided by systemd. You >> can edit that file, > > The file in /usr will be overwritten by the next package update. > >> create your own in /etc/sysctl.d/, > > Yes, local configuration belongs to /etc. > See also "man sysctl.d". Except, of course, that it is apparently Leonard Pottering's announced desire to stop people from using /etc/ -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On 25 February 2015 at 16:43, Josh Boyer wrote: > On Wed, Feb 25, 2015 at 9:35 AM, Ali AlipourR wrote: >>>> Why sysrq is limited to only "sync" command on official fedora kernel? >>> >>> The kernel itself isn't limited. It's just set that way in >>> /usr/lib/sysctl.d/50-default.conf which is provided by systemd. You >>> can edit that file, create your own in /etc/sysctrl.d/, or (as root) >>> set it to whatever you would like via /proc/sys/kernel/sysrq. >> >> Of course it can be changed at runtime, but I mean why official fedora >> kernel shouldn't be configured to allow all (or at least a wider >> subset) of sysrq commands by default? > > Maybe we're getting hung up on a terminology issue, but this isn't a > kernel configuration issue. It's something userspace is doing. > >> This way official fedora live CDs are unsuitable for system recovery >> tasks; you have to change sysrq value every time you use live CDs or >> build your own live CD. > > That's a good point. Since the live images have a "rescue" mode, > maybe there is a way to use a different value when booted into that. > How that would look, I'm not sure. Maybe dracut would need to include > an override file in the initramfs. > > josh AFAIK the live images don't have a rescue mode/boot option; that mode is only available on the non-live installation DVD and the network-install images. -- Ahmad Samir -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On Fri, Feb 27, 2015 at 12:39:23AM +0100, Reindl Harald wrote: > > Am 27.02.2015 um 00:32 schrieb Zbigniew Jędrzejewski-Szmek: > >>All versions might be overkill, but I don't see the harm in the added > >>convenience, either. What's the next step? > >Somebody should do the change :) But there's a snag: systemd-sysctl warns > >about overrides: > >Overwriting earlier assignment of kernel/sysrq in file > >'/etc/sysctl.d/60-local.conf'. > >I think we should change this upstream (downgrade to debug). And thinking > >about this more, creating a separate file seems overkill. Just adding > >a comment in 50-default.conf should be enough OK, done upstream. Should land in F22+ soon enough. http://cgit.freedesktop.org/systemd/systemd/commit/?id=16b65d7f46 http://cgit.freedesktop.org/systemd/systemd/commit/?id=16b65d7f46^ > and i hate all this systemd log flooding so much. One down :) Zbyszek -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
Am 27.02.2015 um 00:32 schrieb Zbigniew Jędrzejewski-Szmek: All versions might be overkill, but I don't see the harm in the added convenience, either. What's the next step? Somebody should do the change :) But there's a snag: systemd-sysctl warns about overrides: Overwriting earlier assignment of kernel/sysrq in file '/etc/sysctl.d/60-local.conf'. I think we should change this upstream (downgrade to debug). And thinking about this more, creating a separate file seems overkill. Just adding a comment in 50-default.conf should be enough and i hate all this systemd log flooding so much. signature.asc Description: OpenPGP digital signature -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On Thu, Feb 26, 2015 at 02:33:17PM -0700, Pete Travis wrote: > On Feb 26, 2015 9:01 AM, "Zbigniew Jędrzejewski-Szmek" > wrote: > > > > On Thu, Feb 26, 2015 at 08:51:46AM -0700, Pete Travis wrote: > > > The only time I've needed sysrq reboots in recent memory was while > running > > > rawhide and knowingly venturing into uncharted territory. If I'm not > the > > > only one, would it make sense to include appropriate sysctl snippets in > > > fedora-release-rawhide ? > > We could ship /etc/sysctl.d/sysrq-enable.conf.disabled (name up for > discussion), > > and interested users could enable it by renaming the file. Maybe even > better > > to provide it the same in all versions. > > > > Zbyszek > > -- > > > > All versions might be overkill, but I don't see the harm in the added > convenience, either. What's the next step? Somebody should do the change :) But there's a snag: systemd-sysctl warns about overrides: Overwriting earlier assignment of kernel/sysrq in file '/etc/sysctl.d/60-local.conf'. I think we should change this upstream (downgrade to debug). And thinking about this more, creating a separate file seems overkill. Just adding a comment in 50-default.conf should be enough. Zbyszek -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On Feb 26, 2015 9:01 AM, "Zbigniew Jędrzejewski-Szmek" wrote: > > On Thu, Feb 26, 2015 at 08:51:46AM -0700, Pete Travis wrote: > > The only time I've needed sysrq reboots in recent memory was while running > > rawhide and knowingly venturing into uncharted territory. If I'm not the > > only one, would it make sense to include appropriate sysctl snippets in > > fedora-release-rawhide ? > We could ship /etc/sysctl.d/sysrq-enable.conf.disabled (name up for discussion), > and interested users could enable it by renaming the file. Maybe even better > to provide it the same in all versions. > > Zbyszek > -- > All versions might be overkill, but I don't see the harm in the added convenience, either. What's the next step? --Pete -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On Thu, Feb 26, 2015 at 08:51:46AM -0700, Pete Travis wrote: > The only time I've needed sysrq reboots in recent memory was while running > rawhide and knowingly venturing into uncharted territory. If I'm not the > only one, would it make sense to include appropriate sysctl snippets in > fedora-release-rawhide ? We could ship /etc/sysctl.d/sysrq-enable.conf.disabled (name up for discussion), and interested users could enable it by renaming the file. Maybe even better to provide it the same in all versions. Zbyszek -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On Feb 25, 2015 1:50 PM, "Reindl Harald" wrote: > > > > Am 25.02.2015 um 21:38 schrieb Zdenek Kabelac: > >> Dne 25.2.2015 v 18:44 Reindl Harald napsal(a): >>> >>> >>> Am 25.02.2015 um 18:37 schrieb Paul Wouters: On Wed, 25 Feb 2015, Lennart Poettering wrote: > Hmm? Syncing is allowed to my knowledge. C-a-d and gdm allow a clean > reboot/poweroff. But sysrq does an abnormal reboot/poweroff, which we > cannot allow. Similar, remounting read-only is also security senstive, > which we cannot allow. > > Without being logged in there's very little you can do on a host right > now, and sysrq should not open up more there by default. You must have forgotten your university days The alternative to not being able to sync-umount-boot using sysrq is to flip the switch. I'd rather have them use sysrq. I said it when they closed X ctrl-alt-backspace and I'll say it now. When you are on console with the power plug, preventing these actions is stupid >>> >>> >>> when you are on a machine where you have pysical only keyboard and >>> mouse it is >>> not - not every PC stands in front of your face - think about kiosk >>> mode and >>> so on... >> >> >> When I read such answers - I always wonder myself - how many kiosk ever >> run Fedora... >> >> It's such a bad idea to optimize Fedora for one-in-milion users and >> those 999.999 has to suffer instead of require 1 guy to configure more >> secure version > > > you can be sure that the need for sysrq is the one-in-milion users just because i am a *heavy user* with a lot of setups and used it 4 times in the past 12 years while restricted it to "kernel.sysrq = 20" long before the systemd change > > it's such a bad idea to *not* optimize out-of-the box for security > > the ones which don't care can disable it, most won't care, nor have a need nor do they even know about a lot of things - this users are also not in the position to fix bad security defaults because they have no idea about it > > > -- > The only time I've needed sysrq reboots in recent memory was while running rawhide and knowingly venturing into uncharted territory. If I'm not the only one, would it make sense to include appropriate sysctl snippets in fedora-release-rawhide ? --Pete -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
Am 25.02.2015 um 21:38 schrieb Zdenek Kabelac: Dne 25.2.2015 v 18:44 Reindl Harald napsal(a): Am 25.02.2015 um 18:37 schrieb Paul Wouters: On Wed, 25 Feb 2015, Lennart Poettering wrote: Hmm? Syncing is allowed to my knowledge. C-a-d and gdm allow a clean reboot/poweroff. But sysrq does an abnormal reboot/poweroff, which we cannot allow. Similar, remounting read-only is also security senstive, which we cannot allow. Without being logged in there's very little you can do on a host right now, and sysrq should not open up more there by default. You must have forgotten your university days The alternative to not being able to sync-umount-boot using sysrq is to flip the switch. I'd rather have them use sysrq. I said it when they closed X ctrl-alt-backspace and I'll say it now. When you are on console with the power plug, preventing these actions is stupid when you are on a machine where you have pysical only keyboard and mouse it is not - not every PC stands in front of your face - think about kiosk mode and so on... When I read such answers - I always wonder myself - how many kiosk ever run Fedora... It's such a bad idea to optimize Fedora for one-in-milion users and those 999.999 has to suffer instead of require 1 guy to configure more secure version you can be sure that the need for sysrq is the one-in-milion users just because i am a *heavy user* with a lot of setups and used it 4 times in the past 12 years while restricted it to "kernel.sysrq = 20" long before the systemd change it's such a bad idea to *not* optimize out-of-the box for security the ones which don't care can disable it, most won't care, nor have a need nor do they even know about a lot of things - this users are also not in the position to fix bad security defaults because they have no idea about it signature.asc Description: OpenPGP digital signature -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
Dne 25.2.2015 v 18:44 Reindl Harald napsal(a): Am 25.02.2015 um 18:37 schrieb Paul Wouters: On Wed, 25 Feb 2015, Lennart Poettering wrote: Hmm? Syncing is allowed to my knowledge. C-a-d and gdm allow a clean reboot/poweroff. But sysrq does an abnormal reboot/poweroff, which we cannot allow. Similar, remounting read-only is also security senstive, which we cannot allow. Without being logged in there's very little you can do on a host right now, and sysrq should not open up more there by default. You must have forgotten your university days The alternative to not being able to sync-umount-boot using sysrq is to flip the switch. I'd rather have them use sysrq. I said it when they closed X ctrl-alt-backspace and I'll say it now. When you are on console with the power plug, preventing these actions is stupid when you are on a machine where you have pysical only keyboard and mouse it is not - not every PC stands in front of your face - think about kiosk mode and so on... When I read such answers - I always wonder myself - how many kiosk ever run Fedora... It's such a bad idea to optimize Fedora for one-in-milion users and those 999.999 has to suffer instead of require 1 guy to configure more secure version. On the other hand - Fedora might easily provide a 'script' to disable all obscure 'security' settings - if that's the only thing to pass the security audit with 'defaults'... And my recent personal experience - I tried to configure NFS to use it between my qemu and host machine - and guess what - first thing which has been instantly removed from host was firewalld as this piece is simply unconfigurable nonsense and the second one is absurdly broken nfs4 - replaced with usable nfs3... People need to do their works and don't have time to spend ours figuring out where the settings has been shifted after some security-person decisions and systemd upgrades Regards Zdenek -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
Am 25.02.2015 um 18:37 schrieb Paul Wouters: On Wed, 25 Feb 2015, Lennart Poettering wrote: Hmm? Syncing is allowed to my knowledge. C-a-d and gdm allow a clean reboot/poweroff. But sysrq does an abnormal reboot/poweroff, which we cannot allow. Similar, remounting read-only is also security senstive, which we cannot allow. Without being logged in there's very little you can do on a host right now, and sysrq should not open up more there by default. You must have forgotten your university days The alternative to not being able to sync-umount-boot using sysrq is to flip the switch. I'd rather have them use sysrq. I said it when they closed X ctrl-alt-backspace and I'll say it now. When you are on console with the power plug, preventing these actions is stupid when you are on a machine where you have pysical only keyboard and mouse it is not - not every PC stands in front of your face - think about kiosk mode and so on... signature.asc Description: OpenPGP digital signature -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
Am 25.02.2015 um 18:47 schrieb Chris Adams: Once upon a time, Reindl Harald said: when you are on a machine where you have pysical only keyboard and mouse it is not - not every PC stands in front of your face - think about kiosk mode and so on... But Fedora out-of-the-box is not secured for that already. An admin needs to do additional configuration to secure for a "console does NOT have physical access" and "console user is NOT admin" setup no - but it makes a difference if you need to care abot 20 or 200 things to secure - many even don't know about sysrq and so would never come to the idea secure sysrq too and so have an unknown door wide open the users which know about it can enable it that's the whole purpose of secure defaults signature.asc Description: OpenPGP digital signature -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
Once upon a time, Reindl Harald said: > when you are on a machine where you have pysical only keyboard and > mouse it is not - not every PC stands in front of your face - think > about kiosk mode and so on... But Fedora out-of-the-box is not secured for that already. An admin needs to do additional configuration to secure for a "console does NOT have physical access" and "console user is NOT admin" setup. -- Chris Adams -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On Wed, 25 Feb 2015, Lennart Poettering wrote: Hmm? Syncing is allowed to my knowledge. C-a-d and gdm allow a clean reboot/poweroff. But sysrq does an abnormal reboot/poweroff, which we cannot allow. Similar, remounting read-only is also security senstive, which we cannot allow. Without being logged in there's very little you can do on a host right now, and sysrq should not open up more there by default. You must have forgotten your university days The alternative to not being able to sync-umount-boot using sysrq is to flip the switch. I'd rather have them use sysrq. I said it when they closed X ctrl-alt-backspace and I'll say it now. When you are on console with the power plug, preventing these actions is stupid. Paul -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On Wed, 25.02.15 11:16, Chris Adams (li...@cmadams.net) wrote: > Once upon a time, Lennart Poettering said: > > We generally default "secure". The thing is that with sysrq you can > > kill arbitrary processes if you have acecss to the console, and other > > things, and that's just too security sensitive. > > There are other useful things, like sync, remount read-only, reboot, > poweroff, that we already allow console users to do other ways by > default. Allowing them to do them through SysRq seems like a good idea > IMHO. Hmm? Syncing is allowed to my knowledge. C-a-d and gdm allow a clean reboot/poweroff. But sysrq does an abnormal reboot/poweroff, which we cannot allow. Similar, remounting read-only is also security senstive, which we cannot allow. Without being logged in there's very little you can do on a host right now, and sysrq should not open up more there by default. Lennart -- Lennart Poettering, Red Hat -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
Once upon a time, Lennart Poettering said: > We generally default "secure". The thing is that with sysrq you can > kill arbitrary processes if you have acecss to the console, and other > things, and that's just too security sensitive. There are other useful things, like sync, remount read-only, reboot, poweroff, that we already allow console users to do other ways by default. Allowing them to do them through SysRq seems like a good idea IMHO. -- Chris Adams -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On Wed, 25.02.15 18:05, Ali AlipourR (alipoo...@gmail.com) wrote: > >> Why sysrq is limited to only "sync" command on official fedora kernel? > > > > The kernel itself isn't limited. It's just set that way in > > /usr/lib/sysctl.d/50-default.conf which is provided by systemd. You > > can edit that file, create your own in /etc/sysctrl.d/, or (as root) > > set it to whatever you would like via /proc/sys/kernel/sysrq. > > Of course it can be changed at runtime, but I mean why official fedora > kernel shouldn't be configured to allow all (or at least a wider > subset) of sysrq commands by default? We generally default "secure". The thing is that with sysrq you can kill arbitrary processes if you have acecss to the console, and other things, and that's just too security sensitive. > This way official fedora live CDs are unsuitable for system recovery > tasks; you have to change sysrq value every time you use live CDs or > build your own live CD. I figure for livecds it would be fine to override this. Lennart -- Lennart Poettering, Red Hat -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On Wed, Feb 25, 2015 at 9:53 AM, Michal Schmidt wrote: > On 02/25/2015 03:43 PM, Josh Boyer wrote: >> On Wed, Feb 25, 2015 at 9:35 AM, Ali AlipourR wrote: >>>>> Why sysrq is limited to only "sync" command on official fedora kernel? >>>> >>>> The kernel itself isn't limited. It's just set that way in >>>> /usr/lib/sysctl.d/50-default.conf which is provided by systemd. You >>>> can edit that file, create your own in /etc/sysctrl.d/, or (as root) >>>> set it to whatever you would like via /proc/sys/kernel/sysrq. >>> >>> Of course it can be changed at runtime, but I mean why official fedora >>> kernel shouldn't be configured to allow all (or at least a wider >>> subset) of sysrq commands by default? >> >> Maybe we're getting hung up on a terminology issue, but this isn't a >> kernel configuration issue. It's something userspace is doing. >> >>> This way official fedora live CDs are unsuitable for system recovery >>> tasks; you have to change sysrq value every time you use live CDs or >>> build your own live CD. >> >> That's a good point. Since the live images have a "rescue" mode, >> maybe there is a way to use a different value when booted into that. >> How that would look, I'm not sure. Maybe dracut would need to include >> an override file in the initramfs. > > I don't follow the reasoning. Why am I more likely to need SysRq in > rescue mode than in normal boot? Rescue mode quite often translates to "debug mode" as well. Things hang, you need to know why, etc. SysRq isn't always required, but it is another tool in the box. josh -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On 02/25/2015 03:43 PM, Josh Boyer wrote: > On Wed, Feb 25, 2015 at 9:35 AM, Ali AlipourR wrote: >>>> Why sysrq is limited to only "sync" command on official fedora kernel? >>> >>> The kernel itself isn't limited. It's just set that way in >>> /usr/lib/sysctl.d/50-default.conf which is provided by systemd. You >>> can edit that file, create your own in /etc/sysctrl.d/, or (as root) >>> set it to whatever you would like via /proc/sys/kernel/sysrq. >> >> Of course it can be changed at runtime, but I mean why official fedora >> kernel shouldn't be configured to allow all (or at least a wider >> subset) of sysrq commands by default? > > Maybe we're getting hung up on a terminology issue, but this isn't a > kernel configuration issue. It's something userspace is doing. > >> This way official fedora live CDs are unsuitable for system recovery >> tasks; you have to change sysrq value every time you use live CDs or >> build your own live CD. > > That's a good point. Since the live images have a "rescue" mode, > maybe there is a way to use a different value when booted into that. > How that would look, I'm not sure. Maybe dracut would need to include > an override file in the initramfs. I don't follow the reasoning. Why am I more likely to need SysRq in rescue mode than in normal boot? Michal -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
>it is nothing someone is using regulary and that settings are security >settings recommended by most auditing tools security part is admit able, but still I think it is too much strict, e.g. what is security problem of having 'r' request enabled? (specially considering that fedora uses relatively unstable gnome-shell) Regards, Ali -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On Wed, Feb 25, 2015 at 9:35 AM, Ali AlipourR wrote: >>> Why sysrq is limited to only "sync" command on official fedora kernel? >> >> The kernel itself isn't limited. It's just set that way in >> /usr/lib/sysctl.d/50-default.conf which is provided by systemd. You >> can edit that file, create your own in /etc/sysctrl.d/, or (as root) >> set it to whatever you would like via /proc/sys/kernel/sysrq. > > Of course it can be changed at runtime, but I mean why official fedora > kernel shouldn't be configured to allow all (or at least a wider > subset) of sysrq commands by default? Maybe we're getting hung up on a terminology issue, but this isn't a kernel configuration issue. It's something userspace is doing. > This way official fedora live CDs are unsuitable for system recovery > tasks; you have to change sysrq value every time you use live CDs or > build your own live CD. That's a good point. Since the live images have a "rescue" mode, maybe there is a way to use a different value when booted into that. How that would look, I'm not sure. Maybe dracut would need to include an override file in the initramfs. josh -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
Am 25.02.2015 um 15:35 schrieb Ali AlipourR: Why sysrq is limited to only "sync" command on official fedora kernel? The kernel itself isn't limited. It's just set that way in /usr/lib/sysctl.d/50-default.conf which is provided by systemd. You can edit that file, create your own in /etc/sysctrl.d/, or (as root) set it to whatever you would like via /proc/sys/kernel/sysrq. Of course it can be changed at runtime, but I mean why official fedora kernel shouldn't be configured to allow all (or at least a wider subset) of sysrq commands by default? This way official fedora live CDs are unsuitable for system recovery tasks; you have to change sysrq value every time you use live CDs or build your own live CD it is nothing someone is using regulary and that settings are security settings recommended by most auditing tools signature.asc Description: OpenPGP digital signature -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On 02/25/2015 03:04 PM, Josh Boyer wrote: > On Wed, Feb 25, 2015 at 8:54 AM, Ali AlipourR wrote: >> Hi, >> >> Why sysrq is limited to only "sync" command on official fedora kernel? > > The kernel itself isn't limited. It's just set that way in > /usr/lib/sysctl.d/50-default.conf which is provided by systemd. You > can edit that file, The file in /usr will be overwritten by the next package update. > create your own in /etc/sysctl.d/, Yes, local configuration belongs to /etc. See also "man sysctl.d". > or (as root) set it to whatever you would like via /proc/sys/kernel/sysrq. Or pass "sysrq_always_enabled" on the kernel command line. sysrq_always_enabled [KNL] Ignore sysrq setting - this boot parameter will neutralize any effect of /proc/sys/kernel/sysrq. Useful for debugging. Michal -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
>> Why sysrq is limited to only "sync" command on official fedora kernel? > > The kernel itself isn't limited. It's just set that way in > /usr/lib/sysctl.d/50-default.conf which is provided by systemd. You > can edit that file, create your own in /etc/sysctrl.d/, or (as root) > set it to whatever you would like via /proc/sys/kernel/sysrq. Of course it can be changed at runtime, but I mean why official fedora kernel shouldn't be configured to allow all (or at least a wider subset) of sysrq commands by default? This way official fedora live CDs are unsuitable for system recovery tasks; you have to change sysrq value every time you use live CDs or build your own live CD. Regards, Ali -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Re: Why sysrq is limited to only "sync" command on official fedora kernel?
On Wed, Feb 25, 2015 at 8:54 AM, Ali AlipourR wrote: > Hi, > > Why sysrq is limited to only "sync" command on official fedora kernel? The kernel itself isn't limited. It's just set that way in /usr/lib/sysctl.d/50-default.conf which is provided by systemd. You can edit that file, create your own in /etc/sysctrl.d/, or (as root) set it to whatever you would like via /proc/sys/kernel/sysrq. josh -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Why sysrq is limited to only "sync" command on official fedora kernel?
Hi, Why sysrq is limited to only "sync" command on official fedora kernel? Regards, Ali -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct