From: Matthew Garrett <matthewgarrett@google.com>
To: jmorris@namei.org
Cc: linux-security@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-api@vger.kernel.org, David Howells <dhowells@redhat.com>,
Matthew Garrett <mjg59@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>
Subject: [PATCH V33 25/30] Lock down perf when in confidentiality mode
Date: Thu, 20 Jun 2019 18:19:36 -0700 [thread overview]
Message-ID: <20190621011941.186255-26-matthewgarrett@google.com> (raw)
In-Reply-To: <20190621011941.186255-1-matthewgarrett@google.com>
From: David Howells <dhowells@redhat.com>
Disallow the use of certain perf facilities that might allow userspace to
access kernel data.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
---
include/linux/security.h | 1 +
kernel/events/core.c | 5 +++++
security/lockdown/lockdown.c | 1 +
3 files changed, 7 insertions(+)
diff --git a/include/linux/security.h b/include/linux/security.h
index 8bf426cdd151..36a9daa13bb0 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -98,6 +98,7 @@ enum lockdown_reason {
LOCKDOWN_KCORE,
LOCKDOWN_KPROBES,
LOCKDOWN_BPF,
+ LOCKDOWN_PERF,
LOCKDOWN_CONFIDENTIALITY_MAX,
};
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 72d06e302e99..ac1045caa44d 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10731,6 +10731,11 @@ SYSCALL_DEFINE5(perf_event_open,
return -EINVAL;
}
+ if ((attr.sample_type & PERF_SAMPLE_REGS_INTR) &&
+ security_is_locked_down(LOCKDOWN_PERF))
+ /* REGS_INTR can leak data, lockdown must prevent this */
+ return -EPERM;
+
/* Only privileged users can get physical addresses */
if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR) &&
perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c
index 0a3bbf1ba01d..14edc475d75c 100644
--- a/security/lockdown/lockdown.c
+++ b/security/lockdown/lockdown.c
@@ -34,6 +34,7 @@ static char *lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1] = {
[LOCKDOWN_KCORE] = "/proc/kcore access",
[LOCKDOWN_KPROBES] = "use of kprobes",
[LOCKDOWN_BPF] = "use of bpf",
+ [LOCKDOWN_PERF] = "unsafe use of perf",
[LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality",
};
--
2.22.0.410.gd8fdbe21b5-goog
next prev parent reply other threads:[~2019-06-21 1:21 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-21 1:19 [PATCH V33 00/30] Lockdown as an LSM Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 01/30] security: Support early LSMs Matthew Garrett
2019-06-21 3:21 ` Kees Cook
2019-06-21 19:26 ` Matthew Garrett
2019-06-21 5:23 ` Andy Lutomirski
2019-06-21 19:27 ` Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 02/30] security: Add a "locked down" LSM hook Matthew Garrett
2019-06-21 3:23 ` Kees Cook
2019-06-21 19:29 ` Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 03/30] security: Add a static lockdown policy LSM Matthew Garrett
2019-06-21 3:44 ` Kees Cook
2019-06-21 19:37 ` Matthew Garrett
2019-06-21 21:04 ` Matthew Garrett
2019-06-21 22:31 ` Mimi Zohar
2019-06-21 1:19 ` [PATCH V33 04/30] Enforce module signatures if the kernel is locked down Matthew Garrett
2019-06-21 3:46 ` Kees Cook
2019-06-21 1:19 ` [PATCH V33 05/30] Restrict /dev/{mem,kmem,port} when " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 06/30] kexec_load: Disable at runtime if " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 07/30] Copy secure_boot flag in boot params across kexec reboot Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 08/30] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 09/30] kexec_file: Restrict at runtime if the kernel is locked down Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 10/30] hibernate: Disable when " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 11/30] uswsusp: " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 12/30] PCI: Lock down BAR access " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 13/30] x86: Lock down IO port " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 14/30] x86/msr: Restrict MSR " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 15/30] ACPI: Limit access to custom_method " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 16/30] acpi: Ignore acpi_rsdp kernel param when the kernel has been " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 17/30] acpi: Disable ACPI table override if the kernel is " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 18/30] Prohibit PCMCIA CIS storage when " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 19/30] Lock down TIOCSSERIAL Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 20/30] Lock down module params that specify hardware parameters (eg. ioport) Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 21/30] x86/mmiotrace: Lock down the testmmiotrace module Matthew Garrett
2019-06-26 12:46 ` Steven Rostedt
2019-06-21 1:19 ` [PATCH V33 22/30] Lock down /proc/kcore Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 23/30] Lock down tracing and perf kprobes when in confidentiality mode Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 24/30] bpf: Restrict bpf when kernel lockdown is " Matthew Garrett
2019-06-21 5:22 ` Andy Lutomirski
2019-06-21 20:05 ` Matthew Garrett
2019-06-26 20:22 ` James Morris
2019-06-27 0:57 ` Andy Lutomirski
2019-06-27 14:35 ` Stephen Smalley
2019-06-27 18:06 ` James Morris
2019-06-27 20:16 ` Stephen Smalley
2019-06-27 23:16 ` Matthew Garrett
2019-06-27 23:23 ` Andy Lutomirski
2019-06-27 23:27 ` Andy Lutomirski
2019-06-28 18:47 ` Matthew Garrett
2019-06-29 23:47 ` Andy Lutomirski
2019-06-21 1:19 ` Matthew Garrett [this message]
2019-06-21 1:19 ` [PATCH V33 26/30] kexec: Allow kexec_file() with appropriate IMA policy when locked down Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 27/30] lockdown: Print current->comm in restriction messages Matthew Garrett
2019-06-21 4:09 ` Kees Cook
2019-06-21 1:19 ` [PATCH V33 28/30] debugfs: Restrict debugfs when the kernel is locked down Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 29/30] tracefs: Restrict tracefs " Matthew Garrett
2019-06-26 13:07 ` Steven Rostedt
2019-06-26 19:39 ` Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 30/30] efi: Restrict efivar_ssdt_load " Matthew Garrett
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190621011941.186255-26-matthewgarrett@google.com \
--to=matthewgarrett@google.com \
--cc=acme@kernel.org \
--cc=dhowells@redhat.com \
--cc=jmorris@namei.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=mjg59@google.com \
--cc=peterz@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).