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-rw-r--r--include/linux/compat.h3
-rw-r--r--kernel/signal.c14
2 files changed, 12 insertions, 5 deletions
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 1a3c4f37e908..de0c13bdcd2c 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -103,6 +103,9 @@ typedef struct compat_sigaltstack {
compat_size_t ss_size;
} compat_stack_t;
#endif
+#ifndef COMPAT_MINSIGSTKSZ
+#define COMPAT_MINSIGSTKSZ MINSIGSTKSZ
+#endif
#define compat_jiffies_to_clock_t(x) \
(((unsigned long)(x) * COMPAT_USER_HZ) / HZ)
diff --git a/kernel/signal.c b/kernel/signal.c
index 5843c541fda9..e4aad0e90882 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3460,7 +3460,8 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
}
static int
-do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp)
+do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp,
+ size_t min_ss_size)
{
struct task_struct *t = current;
@@ -3490,7 +3491,7 @@ do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp)
ss_size = 0;
ss_sp = NULL;
} else {
- if (unlikely(ss_size < MINSIGSTKSZ))
+ if (unlikely(ss_size < min_ss_size))
return -ENOMEM;
}
@@ -3508,7 +3509,8 @@ SYSCALL_DEFINE2(sigaltstack,const stack_t __user *,uss, stack_t __user *,uoss)
if (uss && copy_from_user(&new, uss, sizeof(stack_t)))
return -EFAULT;
err = do_sigaltstack(uss ? &new : NULL, uoss ? &old : NULL,
- current_user_stack_pointer());
+ current_user_stack_pointer(),
+ MINSIGSTKSZ);
if (!err && uoss && copy_to_user(uoss, &old, sizeof(stack_t)))
err = -EFAULT;
return err;
@@ -3519,7 +3521,8 @@ int restore_altstack(const stack_t __user *uss)
stack_t new;
if (copy_from_user(&new, uss, sizeof(stack_t)))
return -EFAULT;
- (void)do_sigaltstack(&new, NULL, current_user_stack_pointer());
+ (void)do_sigaltstack(&new, NULL, current_user_stack_pointer(),
+ MINSIGSTKSZ);
/* squash all but EFAULT for now */
return 0;
}
@@ -3553,7 +3556,8 @@ static int do_compat_sigaltstack(const compat_stack_t __user *uss_ptr,
uss.ss_size = uss32.ss_size;
}
ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss,
- compat_user_stack_pointer());
+ compat_user_stack_pointer(),
+ COMPAT_MINSIGSTKSZ);
if (ret >= 0 && uoss_ptr) {
compat_stack_t old;
memset(&old, 0, sizeof(old));