This is a note to let you know that I've just added the patch titled
arm64: Mark __stack_chk_guard as __ro_after_init
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm64-mark-__stack_chk_guard-as-__ro_after_init.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 864a911b6e4a7fddb28a1df0ab6b13c8c393cb71
Author: Dan Li <ashimida@xxxxxxxxxxxxxxxxx>
Date: Tue Sep 14 17:44:02 2021 +0800
arm64: Mark __stack_chk_guard as __ro_after_init
[ Upstream commit 9fcb2e93f41c07a400885325e7dbdfceba6efaec ]
__stack_chk_guard is setup once while init stage and never changed
after that.
Although the modification of this variable at runtime will usually
cause the kernel to crash (so does the attacker), it should be marked
as __ro_after_init, and it should not affect performance if it is
placed in the ro_after_init section.
Signed-off-by: Dan Li <ashimida@xxxxxxxxxxxxxxxxx>
Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
Link: https://lore.kernel.org/r/1631612642-102881-1-git-send-email-ashimida@xxxxxxxxxxxxxxxxx
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 7d7cfa128b71..f61ef46ebff7 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -56,7 +56,7 @@
#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK)
#include <linux/stackprotector.h>
-unsigned long __stack_chk_guard __read_mostly;
+unsigned long __stack_chk_guard __ro_after_init;
EXPORT_SYMBOL(__stack_chk_guard);
#endif
