diff options
| author | Mark Rutland <mark.rutland@arm.com> | 2017-05-03 16:09:35 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-05-25 14:30:15 +0200 |
| commit | 06dd8281a7d35b677bddc8fdc7366cf55355d002 (patch) | |
| tree | 05793b33bff9e9f7e43581bfbcc0e26a157830ec | |
| parent | c23fee69f5b5c2c6419c5ae4044e828675cf7548 (diff) | |
arm64: uaccess: ensure extension of access_ok() addr
commit a06040d7a791a9177581dcf7293941bd92400856 upstream.
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")
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arm64/include/asm/uaccess.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index b2ede967fe7d..d9ca1f2c0ea8 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -92,11 +92,12 @@ 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; \ |