4.9-stable review patch. If anyone has any objections, please let me know.
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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: David A. Long dave.long@linaro.org Reviewed-by: Julien Thierry julien.thierry@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm/lib/copy_to_user.S | 6 +++++- arch/arm/lib/uaccess_with_memcpy.c | 3 ++- 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 6bd1089b07e0..f598d792bace 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; }