[PATCH 4.9 18/47] module: Add retpoline tag to VERMAGIC

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

commit 6cfb521ac0d5b97470883ff9b7facae264b7ab12 upstream.

Add a marker for retpoline to the module VERMAGIC. This catches the case
when a non RETPOLINE compiled module gets loaded into a retpoline kernel,
making it insecure.

It doesn't handle the case when retpoline has been runtime disabled.  Even
in this case the match of the retcompile status will be enforced.  This
implies that even with retpoline run time disabled all modules loaded need
to be recompiled.

Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Acked-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Cc: rusty@xxxxxxxxxxxxxxx
Cc: arjan.van.de.ven@xxxxxxxxx
Cc: jeyu@xxxxxxxxxx
Cc: torvalds@xxxxxxxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20180116205228.4890-1-andi@xxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 include/linux/vermagic.h |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--- a/include/linux/vermagic.h
+++ b/include/linux/vermagic.h
@@ -24,10 +24,16 @@
 #ifndef MODULE_ARCH_VERMAGIC
 #define MODULE_ARCH_VERMAGIC ""
 #endif
+#ifdef RETPOLINE
+#define MODULE_VERMAGIC_RETPOLINE "retpoline "
+#else
+#define MODULE_VERMAGIC_RETPOLINE ""
+#endif
 
 #define VERMAGIC_STRING 						\
 	UTS_RELEASE " "							\
 	MODULE_VERMAGIC_SMP MODULE_VERMAGIC_PREEMPT 			\
 	MODULE_VERMAGIC_MODULE_UNLOAD MODULE_VERMAGIC_MODVERSIONS	\
-	MODULE_ARCH_VERMAGIC
+	MODULE_ARCH_VERMAGIC						\
+	MODULE_VERMAGIC_RETPOLINE
 





[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]