This is a note to let you know that I've just added the patch titled
ARM: 9290/1: uaccess: Fix KASAN false-positives
to the 5.15-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:
arm-9290-1-uaccess-fix-kasan-false-positives.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1491930f5a70f80697dc40b33848e4b601444e02
Author: Andrew Jeffery <andrew@xxxxxxxx>
Date: Wed Feb 22 00:10:14 2023 +0100
ARM: 9290/1: uaccess: Fix KASAN false-positives
[ Upstream commit ceac10c83b330680cc01ceaaab86cd49f4f30d81 ]
__copy_to_user_memcpy() and __clear_user_memset() had been calling
memcpy() and memset() respectively, leading to false-positive KASAN
reports when starting userspace:
[ 10.707901] Run /init as init process
[ 10.731892] process '/bin/busybox' started with executable stack
[ 10.745234] ==================================================================
[ 10.745796] BUG: KASAN: user-memory-access in __clear_user_memset+0x258/0x3ac
[ 10.747260] Write of size 2687 at addr 000de581 by task init/1
Use __memcpy() and __memset() instead to allow userspace access, which
is of course the intent of these functions.
Signed-off-by: Andrew Jeffery <andrew@xxxxxxxx>
Signed-off-by: Zev Weiss <zev@xxxxxxxxxxxxxxxxx>
Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/arm/lib/uaccess_with_memcpy.c b/arch/arm/lib/uaccess_with_memcpy.c
index 106f83a5ea6d2..35e03f6a62127 100644
--- a/arch/arm/lib/uaccess_with_memcpy.c
+++ b/arch/arm/lib/uaccess_with_memcpy.c
@@ -121,7 +121,7 @@ __copy_to_user_memcpy(void __user *to, const void *from, unsigned long n)
tocopy = n;
ua_flags = uaccess_save_and_enable();
- memcpy((void *)to, from, tocopy);
+ __memcpy((void *)to, from, tocopy);
uaccess_restore(ua_flags);
to += tocopy;
from += tocopy;
@@ -188,7 +188,7 @@ __clear_user_memset(void __user *addr, unsigned long n)
tocopy = n;
ua_flags = uaccess_save_and_enable();
- memset((void *)addr, 0, tocopy);
+ __memset((void *)addr, 0, tocopy);
uaccess_restore(ua_flags);
addr += tocopy;
n -= tocopy;
