userns: Add a Kconfig option to enforce strict kuid and kgid type checks (5673a94c) · Commits · 戴 / test

Make it possible to easily switch between strong mandatory type checks and relaxed type checks so that the code can easily be tested with the type checks and then built with the strong type checks disabled so the resulting code can be used. Require strong mandatory type checks when enabling the user namespace. It is very simple to make a typo and use the wrong type allowing conversions to/from userspace values to be bypassed by accident, the strong type checks prevent this. Acked-by:

Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by:

Eric W. Biederman <ebiederm@xmission.com>

include/linux/uidgid.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -17,7 +17,7 @@
		struct user_namespace;
		extern struct user_namespace init_user_ns;

		#if defined(NOTYET)
		#ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS

		typedef struct {
		uid_t val;

init/Kconfig

+11 −1

Original line number	Diff line number	Diff line
		@@ -828,7 +828,8 @@ config IPC_NS
		config USER_NS
		bool "User namespace (EXPERIMENTAL)"
		depends on EXPERIMENTAL
		default y
		select UIDGID_STRICT_TYPE_CHECKS
		default n
		help
		This allows containers, i.e. vservers, to use user namespaces
		to provide different user info for different servers.
		@@ -852,6 +853,15 @@ config NET_NS

		endif # NAMESPACES

		config UIDGID_STRICT_TYPE_CHECKS
		bool "Require conversions between uid/gids and their internal representation"
		default n
		help
		While the nececessary conversions are being added to all subsystems this option allows
		the code to continue to build for unconverted subsystems.

		Say Y here if you want the strict type checking enabled

		config SCHED_AUTOGROUP
		bool "Automatic process group scheduling"
		select EVENTFD

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