From: Andrew Jeffery andrew@aj.id.au
[ 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@aj.id.au Signed-off-by: Zev Weiss zev@bewilderbeest.net Reviewed-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Russell King (Oracle) rmk+kernel@armlinux.org.uk Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm/lib/uaccess_with_memcpy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm/lib/uaccess_with_memcpy.c b/arch/arm/lib/uaccess_with_memcpy.c index 14eecaaf295fa..e4c2677cc1e9e 100644 --- a/arch/arm/lib/uaccess_with_memcpy.c +++ b/arch/arm/lib/uaccess_with_memcpy.c @@ -116,7 +116,7 @@ __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; @@ -178,7 +178,7 @@ __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;