--- kernel/compat.c

+++ kernel/compat.c

@@ -25,6 +25,7 @@

#include <linux/posix-timers.h>

#include <linux/times.h>

#include <linux/ptrace.h>

+#include <linux/module.h>

#include <asm/uaccess.h>

@@ -494,29 +495,26 @@ asmlinkage long compat_sys_sched_getaffi

{

int ret;

cpumask_var_t mask;

- unsigned long *k;

- unsigned int min_length = cpumask_size();

-

- if (nr_cpu_ids <= BITS_PER_COMPAT_LONG)

- min_length = sizeof(compat_ulong_t);

- if (len < min_length)

+ if ((len * BITS_PER_BYTE) < nr_cpu_ids)

+ return -EINVAL;

+ if (len & (sizeof(compat_ulong_t)-1))

return -EINVAL;

if (!alloc_cpumask_var(&mask, GFP_KERNEL))

return -ENOMEM;

ret = sched_getaffinity(pid, mask);

- if (ret < 0)

- goto out;

+ if (ret == 0) {

+ size_t retlen = min_t(size_t, len, cpumask_size());

- k = cpumask_bits(mask);

- ret = compat_put_bitmap(user_mask_ptr, k, min_length * 8);

- if (ret == 0)

- ret = min_length;

-

-out:

+ if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8))

+ ret = -EFAULT;

+ else

+ ret = retlen;

+ }

free_cpumask_var(mask);

+

return ret;

}

@@ -1139,3 +1137,24 @@ compat_sys_sysinfo(struct compat_sysinfo

return 0;

}

+

+/*

+ * Allocate user-space memory for the duration of a single system call,

+ * in order to marshall parameters inside a compat thunk.

+ */

+void __user *compat_alloc_user_space(unsigned long len)

+{

+ void __user *ptr;

+

+ /* If len would occupy more than half of the entire compat space... */

+ if (unlikely(len > (((compat_uptr_t)~0) >> 1)))

+ return NULL;

+

+ ptr = arch_compat_alloc_user_space(len);

+

+ if (unlikely(!access_ok(VERIFY_WRITE, ptr, len)))

+ return NULL;

+

+ return ptr;

+}

+EXPORT_SYMBOL_GPL(compat_alloc_user_space);