[22/27] Lock down /proc/kcore

Message ID	20190306235913.6631-23-matthewgarrett@google.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-security-module-owner@kernel.org> Date: Wed, 6 Mar 2019 15:59:08 -0800 In-Reply-To: <20190306235913.6631-1-matthewgarrett@google.com> Message-Id: <20190306235913.6631-23-matthewgarrett@google.com> Mime-Version: 1.0 References: <20190306235913.6631-1-matthewgarrett@google.com> Subject: [PATCH 22/27] Lock down /proc/kcore 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 Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk
Series	[PULL,REQUEST] Kernel lockdown patches for 5.2 \| expand [PULL,REQUEST] Kernel lockdown patches for 5.2 [02/27] Add a SysRq option to lift kernel lockdown [03/27] Enforce module signatures if the kernel is locked down [04/27] Restrict /dev/{mem,kmem,port} when the kernel is locked down [05/27] kexec_load: Disable at runtime if the kernel is locked down [06/27] Copy secure_boot flag in boot params across kexec reboot [07/27] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE [08/27] kexec_file: Restrict at runtime if the kernel is locked down [09/27] hibernate: Disable when the kernel is locked down [10/27] uswsusp: Disable when the kernel is locked down [11/27] PCI: Lock down BAR access when the kernel is locked down [12/27] x86: Lock down IO port access when the kernel is locked down [13/27] x86/msr: Restrict MSR access when the kernel is locked down [14/27] ACPI: Limit access to custom_method when the kernel is locked down [15/27] acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down [16/27] acpi: Disable ACPI table override if the kernel is locked down [17/27] acpi: Disable APEI error injection if the kernel is locked down [18/27] Prohibit PCMCIA CIS storage when the kernel is locked down [19/27] Lock down TIOCSSERIAL [20/27] Lock down module params that specify hardware parameters (eg. ioport) [21/27] x86/mmiotrace: Lock down the testmmiotrace module [22/27] Lock down /proc/kcore [23/27] Lock down kprobes [24/27] bpf: Restrict kernel image access functions when the kernel is locked down [25/27] Lock down perf [26/27] debugfs: Restrict debugfs when the kernel is locked down [27/27] lockdown: Print current->comm in restriction messages

Message ID

20190306235913.6631-23-matthewgarrett@google.com (mailing list archive)

State

New, archived

Headers

Date: Wed,  6 Mar 2019 15:59:08 -0800
In-Reply-To: <20190306235913.6631-1-matthewgarrett@google.com>
Message-Id: <20190306235913.6631-23-matthewgarrett@google.com>
Mime-Version: 1.0
References: <20190306235913.6631-1-matthewgarrett@google.com>
Subject: [PATCH 22/27] Lock down /proc/kcore
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
Content-Type: text/plain; charset="UTF-8"
Sender: owner-linux-security-module@vger.kernel.org
Precedence: bulk

Series

[PULL,REQUEST] Kernel lockdown patches for 5.2 | expand

Commit Message

Matthew Garrett March 6, 2019, 11:59 p.m. UTC

From: David Howells <dhowells@redhat.com>

Disallow access to /proc/kcore when the kernel is locked down to prevent
access to cryptographic data.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Matthew Garrett <matthewgarrett@google.com>
---
 fs/proc/kcore.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index bbcc185062bb..d50ebfbf3dbb 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -518,6 +518,8 @@  read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
 
 static int open_kcore(struct inode *inode, struct file *filp)
 {
+	if (kernel_is_locked_down("/proc/kcore"))
+		return -EPERM;
 	if (!capable(CAP_SYS_RAWIO))
 		return -EPERM;

[22/27] Lock down /proc/kcore

Commit Message

Patch