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Groups > linux.kernel > #1617937
| From | Alexei Starovoitov <alexei.starovoitov@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 20/24] bpf: Restrict kernel image access functions when the kernel is locked down |
| Date | 2017-04-06 14:30 +0200 |
| Message-ID | <tteI3-8tl-45@gated-at.bofh.it> (permalink) |
| References | <tsZzj-7hF-5@gated-at.bofh.it> <tsZzl-7hF-37@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed, Apr 05, 2017 at 09:17:25PM +0100, David Howells wrote:
> From: Chun-Yi Lee <jlee@suse.com>
>
> There are some bpf functions can be used to read kernel memory:
> bpf_probe_read, bpf_probe_write_user and bpf_trace_printk. These allow
> private keys in kernel memory (e.g. the hibernation image signing key) to
> be read by an eBPF program. Prohibit those functions when the kernel is
> locked down.
>
> Signed-off-by: Chun-Yi Lee <jlee@suse.com>
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: netdev@vger.kernel.org
> ---
>
> kernel/trace/bpf_trace.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index cee9802cf3e0..7fde851f207b 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -65,6 +65,11 @@ BPF_CALL_3(bpf_probe_read, void *, dst, u32, size, const void *, unsafe_ptr)
> {
> int ret;
>
> + if (kernel_is_locked_down()) {
> + memset(dst, 0, size);
> + return -EPERM;
> + }
this will obviously break the program. How about disabling loading tracing
programs during the lockdown completely?
Also is there a description of what this lockdown trying to accomplish?
The cover letter is scarce in details.
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[PATCH 00/24] Kernel lockdown David Howells <dhowells@redhat.com> - 2017-04-05 22:20 +0200
[PATCH 24/24] Lock down module params that specify hardware parameters (eg. ioport) David Howells <dhowells@redhat.com> - 2017-04-05 22:20 +0200
[PATCH 03/24] efi: Lock down the kernel if booted in secure boot mode David Howells <dhowells@redhat.com> - 2017-04-05 22:20 +0200
[PATCH 20/24] bpf: Restrict kernel image access functions when the kernel is locked down David Howells <dhowells@redhat.com> - 2017-04-05 22:20 +0200
Re: [PATCH 20/24] bpf: Restrict kernel image access functions when the kernel is locked down Alexei Starovoitov <alexei.starovoitov@gmail.com> - 2017-04-06 14:30 +0200
Re: [PATCH 20/24] bpf: Restrict kernel image access functions when the kernel is locked down Ard Biesheuvel <ard.biesheuvel@linaro.org> - 2017-04-06 14:50 +0200
[PATCH 12/24] PCI: Lock down BAR access when the kernel is locked down David Howells <dhowells@redhat.com> - 2017-04-05 22:20 +0200
[PATCH 15/24] asus-wmi: Restrict debugfs interface when the kernel is locked down David Howells <dhowells@redhat.com> - 2017-04-05 22:20 +0200
Re: [PATCH 15/24] asus-wmi: Restrict debugfs interface when the kernel is locked down Andy Shevchenko <andy.shevchenko@gmail.com> - 2017-04-07 12:30 +0200
Re: [PATCH 15/24] asus-wmi: Restrict debugfs interface when the kernel is locked down David Howells <dhowells@redhat.com> - 2017-04-07 15:00 +0200
Re: [PATCH 15/24] asus-wmi: Restrict debugfs interface when the kernel is locked down Andy Shevchenko <andy.shevchenko@gmail.com> - 2017-04-09 13:20 +0200
Re: [PATCH 15/24] asus-wmi: Restrict debugfs interface when the kernel is locked down David Howells <dhowells@redhat.com> - 2017-04-10 15:20 +0200
[PATCH 02/24] Add the ability to lock down access to the running kernel image David Howells <dhowells@redhat.com> - 2017-04-05 22:20 +0200
[PATCH 07/24] kexec: Disable at runtime if the kernel is locked down David Howells <dhowells@redhat.com> - 2017-04-05 22:20 +0200
Re: [PATCH 07/24] kexec: Disable at runtime if the kernel is locked down Dave Young <dyoung@redhat.com> - 2017-04-07 05:10 +0200
[PATCH 08/24] Copy secure_boot flag in boot params across kexec reboot David Howells <dhowells@redhat.com> - 2017-04-05 22:20 +0200
[PATCH 06/24] Add a sysrq option to exit secure boot mode David Howells <dhowells@redhat.com> - 2017-04-05 22:20 +0200
[PATCH 10/24] hibernate: Disable when the kernel is locked down David Howells <dhowells@redhat.com> - 2017-04-05 22:20 +0200
[PATCH 14/24] x86: Restrict MSR access when the kernel is locked down David Howells <dhowells@redhat.com> - 2017-04-05 22:30 +0200
[PATCH 04/24] Enforce module signatures if the kernel is locked down David Howells <dhowells@redhat.com> - 2017-04-05 22:30 +0200
[PATCH 11/24] uswsusp: Disable when the kernel is locked down David Howells <dhowells@redhat.com> - 2017-04-05 22:30 +0200
Re: [PATCH 11/24] uswsusp: Disable when the kernel is locked down "Rafael J. Wysocki" <rafael@kernel.org> - 2017-04-06 01:40 +0200
Re: [PATCH 11/24] uswsusp: Disable when the kernel is locked down Oliver Neukum <oneukum@suse.com> - 2017-04-06 08:50 +0200
Re: [PATCH 11/24] uswsusp: Disable when the kernel is locked down David Howells <dhowells@redhat.com> - 2017-04-06 11:30 +0200
Re: [PATCH 11/24] uswsusp: Disable when the kernel is locked down "Rafael J. Wysocki" <rafael@kernel.org> - 2017-04-06 22:20 +0200
Re: [PATCH 11/24] uswsusp: Disable when the kernel is locked down Jiri Kosina <jikos@kernel.org> - 2017-04-06 22:30 +0200
Re: [PATCH 11/24] uswsusp: Disable when the kernel is locked down poma <pomidorabelisima@gmail.com> - 2017-04-08 05:30 +0200
Re: [PATCH 11/24] uswsusp: Disable when the kernel is locked down "Rafael J. Wysocki" <rafael@kernel.org> - 2017-04-06 22:20 +0200
Re: [PATCH 11/24] uswsusp: Disable when the kernel is locked down David Howells <dhowells@redhat.com> - 2017-04-06 09:00 +0200
Re: [PATCH 11/24] uswsusp: Disable when the kernel is locked down "Rafael J. Wysocki" <rafael@kernel.org> - 2017-04-06 22:20 +0200
[PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set David Howells <dhowells@redhat.com> - 2017-04-05 22:30 +0200
Re: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set Dave Young <dyoung@redhat.com> - 2017-04-07 05:10 +0200
Re: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set Mimi Zohar <zohar@linux.vnet.ibm.com> - 2017-04-07 05:50 +0200
Re: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set Dave Young <dyoung@redhat.com> - 2017-04-07 08:20 +0200
Re: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set David Howells <dhowells@redhat.com> - 2017-04-07 09:10 +0200
Re: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set Dave Young <dyoung@redhat.com> - 2017-04-07 09:50 +0200
Re: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set Mimi Zohar <zohar@linux.vnet.ibm.com> - 2017-04-07 10:30 +0200
Re: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set Dave Young <dyoung@redhat.com> - 2017-04-07 10:50 +0200
Re: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set Mimi Zohar <zohar@linux.vnet.ibm.com> - 2017-04-07 09:50 +0200
Re: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set Dave Young <dyoung@redhat.com> - 2017-04-07 10:10 +0200
Re: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set David Howells <dhowells@redhat.com> - 2017-04-07 09:20 +0200
Re: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set Mimi Zohar <zohar@linux.vnet.ibm.com> - 2017-04-07 09:50 +0200
Re: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set David Howells <dhowells@redhat.com> - 2017-04-07 11:20 +0200
Re: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set Mimi Zohar <zohar@linux.vnet.ibm.com> - 2017-04-07 14:40 +0200
Re: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set David Howells <dhowells@redhat.com> - 2017-04-10 15:30 +0200
Re: [PATCH 00/24] Kernel lockdown "Austin S. Hemmelgarn" <ahferroin7@gmail.com> - 2017-04-07 18:10 +0200
Re: [PATCH 00/24] Kernel lockdown Justin Forbes <jmforbes@linuxtx.org> - 2017-04-07 18:40 +0200
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