lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:	Mon, 30 Sep 2013 02:31:08 +0100
From:	Ben Hutchings <>
To:	Greg Kroah-Hartman <>,
	Jiri Slaby <>
Cc:	Bastian Blank <>,
	LKML <>
Subject: [PATCH] sysrq: Allow access to sensitive keys to be restricted by

From: Bastian Blank <>

Add a Kconfig variable to set the initial value of the Magic SysRq mask
(sysctl: kernel.sysrq).

Signed-off-by: Ben Hutchings <>
This has been in Debian for a while, but should probably be signed-off
by Bastian as well.

Debian sets this to 0x01b6, which excludes.

          8 - enable debugging dumps of processes etc.
         64 - enable signalling of processes (term, kill, oom-kill)


--- a/include/linux/sysrq.h
+++ b/include/linux/sysrq.h
@@ -18,7 +18,7 @@
 #include <linux/types.h>
 /* Enable/disable SYSRQ support by default (0==no, 1==yes). */
 /* Possible values of bitmask for enabling sysrq functions */
 /* 0x0001 is reserved for enable everything */
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -312,6 +312,14 @@ config MAGIC_SYSRQ
 	  keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
 	  unless you really know what this hack does.
+	hex "Default mask for Magic SysRq keys on the console"
+	depends on MAGIC_SYSRQ
+	default 1
+	help
+	  Specifies the default mask for the allowed SysRq keys.  This can be
+	  used to disable several sensitive keys by default.
 	bool "Kernel debugging"

Ben Hutchings
Life is like a sewer:
what you get out of it depends on what you put into it.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists