diff mbox series

[ARM32,v4.4,V2,36/47] ARM: 8797/1: spectre-v1.1: harden __copy_to_user

Message ID d4353075bcd15cf29b4ff5f0d8dada48a4c28ea2.1564646727.git.viresh.kumar@linaro.org
State New
Headers show
Series V4.4 backport of arm32 Spectre patches | expand

Commit Message

Viresh Kumar Aug. 1, 2019, 8:16 a.m. UTC 
From: Julien Thierry <julien.thierry@arm.com>


Commit a1d09e074250fad24f1b993f327b18cc6812eb7a upstream.

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>

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

---
 arch/arm/lib/copy_to_user.S        | 6 +++++-
 arch/arm/lib/uaccess_with_memcpy.c | 3 ++-
 2 files changed, 7 insertions(+), 2 deletions(-)

-- 
2.21.0.rc0.269.g1a574e7a288b
diff mbox series

Patch

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 588bbc288396..0b4fe892d00b 100644
--- a/arch/arm/lib/uaccess_with_memcpy.c
+++ b/arch/arm/lib/uaccess_with_memcpy.c
@@ -153,7 +153,8 @@  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;
 }