diff options
| author | Will Deacon <will.deacon@arm.com> | 2018-02-05 15:34:24 +0000 |
|---|---|---|
| committer | Alex Shi <alex.shi@linaro.org> | 2018-02-26 15:43:51 +0800 |
| commit | dd95c33a00a5e46b3c81098d7e5fe82d534f0907 (patch) | |
| tree | 38be1f8abff1627c3813b0e23a4c695952386637 /arch/arm64 | |
| parent | 1063a857678a2bf8a605d42b99e64f8b0e1ed816 (diff) | |
arm64: futex: Mask __user pointers prior to dereference
commit 91b2d3442f6a upstream.
The arm64 futex code has some explicit dereferencing of user pointers
where performing atomic operations in response to a futex command. This
patch uses masking to limit any speculative futex operations to within
the user address space.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
change on old futex_atomic_op_inuser function instead of
arch_futex_atomic_op_inuser in arch/arm64/include/asm/futex.h
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/futex.h | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/arm64/include/asm/futex.h b/arch/arm64/include/asm/futex.h index 85c4a8981d47..1943cf623366 100644 --- a/arch/arm64/include/asm/futex.h +++ b/arch/arm64/include/asm/futex.h @@ -48,13 +48,14 @@ do { \ } while (0) static inline int -futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) +futex_atomic_op_inuser (int encoded_op, u32 __user *_uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; int oparg = (encoded_op << 8) >> 20; int cmparg = (encoded_op << 20) >> 20; int oldval = 0, ret, tmp; + u32 __user *uaddr = __uaccess_mask_ptr(_uaddr); if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; @@ -106,15 +107,17 @@ futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) } static inline int -futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *_uaddr, u32 oldval, u32 newval) { int ret = 0; u32 val, tmp; + u32 __user *uaddr; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) + if (!access_ok(VERIFY_WRITE, _uaddr, sizeof(u32))) return -EFAULT; + uaddr = __uaccess_mask_ptr(_uaddr); uaccess_enable(); asm volatile("// futex_atomic_cmpxchg_inatomic\n" " prfm pstl1strm, %2\n" |