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From: Matthew Garrett <matthewgarrett@google.com>
To: jmorris@namei.org
Cc: linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org, dhowells@redhat.com
Subject: [PATCH 25/27] Lock down perf
Date: Wed,  6 Mar 2019 15:59:11 -0800
Message-ID: <20190306235913.6631-26-matthewgarrett@google.com> (raw)
In-Reply-To: <20190306235913.6631-1-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 <matthewgarrett@google.com>
---
 kernel/events/core.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 3cd13a30f732..7748c6f39992 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10461,6 +10461,11 @@ SYSCALL_DEFINE5(perf_event_open,
 			return -EINVAL;
 	}
 
+	if ((attr.sample_type & PERF_SAMPLE_REGS_INTR) &&
+	    kernel_is_locked_down("PERF_SAMPLE_REGS_INTR"))
+		/* 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))
-- 
2.21.0.352.gf09ad66450-goog


  parent reply index

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-06 23:58 [PULL REQUEST] Kernel lockdown patches for 5.2 Matthew Garrett
2019-03-06 23:58 ` [PATCH 01/27] Add the ability to lock down access to the running kernel image Matthew Garrett
2019-03-06 23:58 ` [PATCH 02/27] Add a SysRq option to lift kernel lockdown Matthew Garrett
2019-03-07  0:09   ` Randy Dunlap
2019-03-07  0:12     ` Matthew Garrett
2019-03-06 23:58 ` [PATCH 03/27] Enforce module signatures if the kernel is locked down Matthew Garrett
2019-03-08 23:00   ` James Morris
2019-03-08 23:30     ` Matthew Garrett
2019-03-09  4:45       ` James Morris
2019-03-06 23:58 ` [PATCH 04/27] Restrict /dev/{mem,kmem,port} when " Matthew Garrett
2019-03-06 23:58 ` [PATCH 05/27] kexec_load: Disable at runtime if " Matthew Garrett
2019-03-06 23:58 ` [PATCH 06/27] Copy secure_boot flag in boot params across kexec reboot Matthew Garrett
2019-03-06 23:58 ` [PATCH 07/27] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE Matthew Garrett
2019-03-06 23:58 ` [PATCH 08/27] kexec_file: Restrict at runtime if the kernel is locked down Matthew Garrett
2019-03-06 23:58 ` [PATCH 09/27] hibernate: Disable when " Matthew Garrett
2019-03-07 14:55   ` Alan Cox
2019-03-07 17:32     ` Matthew Garrett
2019-03-18 18:55       ` Alan Cox
2019-03-06 23:58 ` [PATCH 10/27] uswsusp: " Matthew Garrett
2019-03-06 23:58 ` [PATCH 11/27] PCI: Lock down BAR access " Matthew Garrett
2019-03-06 23:58 ` [PATCH 12/27] x86: Lock down IO port " Matthew Garrett
2019-03-06 23:58 ` [PATCH 13/27] x86/msr: Restrict MSR " Matthew Garrett
2019-03-06 23:59 ` [PATCH 14/27] ACPI: Limit access to custom_method " Matthew Garrett
2019-03-06 23:59 ` [PATCH 15/27] acpi: Ignore acpi_rsdp kernel param when the kernel has been " Matthew Garrett
2019-03-06 23:59 ` [PATCH 16/27] acpi: Disable ACPI table override if the kernel is " Matthew Garrett
2019-03-06 23:59 ` [PATCH 17/27] acpi: Disable APEI error injection " Matthew Garrett
2019-03-06 23:59 ` [PATCH 18/27] Prohibit PCMCIA CIS storage when " Matthew Garrett
2019-03-06 23:59 ` [PATCH 19/27] Lock down TIOCSSERIAL Matthew Garrett
2019-03-06 23:59 ` [PATCH 20/27] Lock down module params that specify hardware parameters (eg. ioport) Matthew Garrett
2019-03-06 23:59 ` [PATCH 21/27] x86/mmiotrace: Lock down the testmmiotrace module Matthew Garrett
2019-03-06 23:59 ` [PATCH 22/27] Lock down /proc/kcore Matthew Garrett
2019-03-06 23:59 ` [PATCH 23/27] Lock down kprobes Matthew Garrett
2019-03-06 23:59 ` [PATCH 24/27] bpf: Restrict kernel image access functions when the kernel is locked down Matthew Garrett
2019-03-06 23:59 ` Matthew Garrett [this message]
2019-03-06 23:59 ` [PATCH 26/27] debugfs: Restrict debugfs " Matthew Garrett
2019-04-25 10:49   ` Vasily Gorbik
2019-04-25 21:44     ` Matthew Garrett
2019-03-06 23:59 ` [PATCH 27/27] lockdown: Print current->comm in restriction messages Matthew Garrett
2019-03-07  3:56 ` [PULL REQUEST] Kernel lockdown patches for 5.2 Mimi Zohar
2019-03-07  4:24   ` Matthew Garrett
2019-03-12  0:42     ` Matthew Garrett
2019-03-12  1:52       ` Mimi Zohar
2019-03-07 15:59 ` [PATCH 02/27] Add a SysRq option to lift kernel lockdown David Howells
  -- strict thread matches above, loose matches on Subject: below --
2019-02-28 21:28 [PULL REQUEST] Lock down patches Matthew Garrett
2019-02-28 23:11 ` [PATCH 01/27] Add the ability to lock down access to the running kernel image Matthew Garrett
2019-02-28 23:12   ` [PATCH 25/27] Lock down perf Matthew Garrett

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