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authorJulien Thierry <julien.thierry@arm.com>2018-09-11 11:15:12 +0200
committerRussell King <rmk+kernel@armlinux.org.uk>2018-10-05 11:51:15 +0200
commita1d09e074250fad24f1b993f327b18cc6812eb7a (patch)
tree92904d2fbb862da96ffdfa670f7ab1556239553f /arch/arm/lib
parentARM: 8796/1: spectre-v1,v1.1: provide helpers for address sanitization (diff)
downloadlinux-a1d09e074250fad24f1b993f327b18cc6812eb7a.tar.xz
linux-a1d09e074250fad24f1b993f327b18cc6812eb7a.zip
ARM: 8797/1: spectre-v1.1: harden __copy_to_user
Sanitize user pointer given to __copy_to_user, both for standard version and memcopy version of the user accessor. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm/lib')
-rw-r--r--arch/arm/lib/copy_to_user.S6
-rw-r--r--arch/arm/lib/uaccess_with_memcpy.c3
2 files changed, 7 insertions, 2 deletions
diff --git a/arch/arm/lib/copy_to_user.S b/arch/arm/lib/copy_to_user.S
index caf5019d8161..970abe521197 100644
--- a/arch/arm/lib/copy_to_user.S
+++ b/arch/arm/lib/copy_to_user.S
@@ -94,6 +94,11 @@
ENTRY(__copy_to_user_std)
WEAK(arm_copy_to_user)
+#ifdef CONFIG_CPU_SPECTRE
+ get_thread_info r3
+ ldr r3, [r3, #TI_ADDR_LIMIT]
+ uaccess_mask_range_ptr r0, r2, r3, ip
+#endif
#include "copy_template.S"
@@ -108,4 +113,3 @@ ENDPROC(__copy_to_user_std)
rsb r0, r0, r2
copy_abort_end
.popsection
-
diff --git a/arch/arm/lib/uaccess_with_memcpy.c b/arch/arm/lib/uaccess_with_memcpy.c
index 9b4ed1728616..73dc7360cbdd 100644
--- a/arch/arm/lib/uaccess_with_memcpy.c
+++ b/arch/arm/lib/uaccess_with_memcpy.c
@@ -152,7 +152,8 @@ arm_copy_to_user(void __user *to, const void *from, unsigned long n)
n = __copy_to_user_std(to, from, n);
uaccess_restore(ua_flags);
} else {
- n = __copy_to_user_memcpy(to, from, n);
+ n = __copy_to_user_memcpy(uaccess_mask_range_ptr(to, n),
+ from, n);
}
return n;
}