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authorMark Rutland <mark.rutland@arm.com>2017-05-03 16:09:35 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2017-05-09 17:46:51 +0100
commita06040d7a791a9177581dcf7293941bd92400856 (patch)
treed98c82e80ac702b224342b2e49072319a9545ea8 /arch/arm64/include/asm/uaccess.h
parentarm64: ensure extension of smp_store_release value (diff)
downloadlinux-dev-a06040d7a791a9177581dcf7293941bd92400856.tar.xz
linux-dev-a06040d7a791a9177581dcf7293941bd92400856.zip
arm64: uaccess: ensure extension of access_ok() addr
Our access_ok() simply hands its arguments over to __range_ok(), which implicitly assummes that the addr parameter is 64 bits wide. This isn't necessarily true for compat code, which might pass down a 32-bit address parameter. In these cases, we don't have a guarantee that the address has been zero extended to 64 bits, and the upper bits of the register may contain unknown values, potentially resulting in a suprious failure. Avoid this by explicitly casting the addr parameter to an unsigned long (as is done on other architectures), ensuring that the parameter is widened appropriately. Fixes: 0aea86a2176c ("arm64: User access library functions") Cc: <stable@vger.kernel.org> # 3.7.x- Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to '')
-rw-r--r--arch/arm64/include/asm/uaccess.h3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 0221029e27ff..e6540471dcda 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -95,11 +95,12 @@ static inline void set_fs(mm_segment_t fs)
*/
#define __range_ok(addr, size) \
({ \
+ unsigned long __addr = (unsigned long __force)(addr); \
unsigned long flag, roksum; \
__chk_user_ptr(addr); \
asm("adds %1, %1, %3; ccmp %1, %4, #2, cc; cset %0, ls" \
: "=&r" (flag), "=&r" (roksum) \
- : "1" (addr), "Ir" (size), \
+ : "1" (__addr), "Ir" (size), \
"r" (current_thread_info()->addr_limit) \
: "cc"); \
flag; \