24 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			24 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
What:		/sys/fs/selinux/checkreqprot
 | 
						|
Date:		April 2005 (predates git)
 | 
						|
KernelVersion:	2.6.12-rc2 (predates git)
 | 
						|
Contact:	selinux@vger.kernel.org
 | 
						|
Description:
 | 
						|
 | 
						|
	The selinuxfs "checkreqprot" node allows SELinux to be configured
 | 
						|
	to check the protection requested by userspace for mmap/mprotect
 | 
						|
	calls instead of the actual protection applied by the kernel.
 | 
						|
	This was a compatibility mechanism for legacy userspace and
 | 
						|
	for the READ_IMPLIES_EXEC personality flag.  However, if set to
 | 
						|
	1, it weakens security by allowing mappings to be made executable
 | 
						|
	without authorization by policy.  The default value of checkreqprot
 | 
						|
	at boot was changed starting in Linux v4.4 to 0 (i.e. check the
 | 
						|
	actual protection), and Android and Linux distributions have been
 | 
						|
	explicitly writing a "0" to /sys/fs/selinux/checkreqprot during
 | 
						|
	initialization for some time.  Support for setting checkreqprot to 1
 | 
						|
	will be	removed no sooner than June 2021, at which point the kernel
 | 
						|
	will always cease using checkreqprot internally and will always
 | 
						|
	check the actual protections being applied upon mmap/mprotect calls.
 | 
						|
	The checkreqprot selinuxfs node will remain for backward compatibility
 | 
						|
	but will discard writes of the "0" value and will reject writes of the
 | 
						|
	"1" value when this mechanism is removed.
 |