diff --git a/Makefile b/Makefile
index 5382c55..096cde6 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 VERSION = 2
 PATCHLEVEL = 6
 SUBLEVEL = 27
-EXTRAVERSION = .51
+EXTRAVERSION = .52-rc2
 NAME = Trembling Tortoise
 
 # *DOCUMENTATION*
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 3384255..9d3c576 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -589,6 +589,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
 	unsigned long address;
 	int write, si_code;
 	int fault;
+	int should_exit_no_context = 0;
 #ifdef CONFIG_X86_64
 	unsigned long flags;
 #endif
@@ -876,6 +877,9 @@ no_context:
 	oops_end(flags, regs, SIGKILL);
 #endif
 
+	if (should_exit_no_context)
+		return;
+
 /*
  * We ran out of memory, or some other thing happened to us that made
  * us unable to handle the page fault gracefully.
@@ -901,8 +905,11 @@ do_sigbus:
 	up_read(&mm->mmap_sem);
 
 	/* Kernel mode? Handle exceptions or die */
-	if (!(error_code & PF_USER))
+	if (!(error_code & PF_USER)) {
+		should_exit_no_context = 1;
 		goto no_context;
+	}
+
 #ifdef CONFIG_X86_32
 	/* User space => ok to do another page fault */
 	if (is_prefetch(regs, address, error_code))
diff --git a/mm/memory.c b/mm/memory.c
index 1300b70..7e308fc 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2396,6 +2396,26 @@ out_nomap:
 }
 
 /*
+ * This is like a special single-page "expand_downwards()",
+ * except we must first make sure that 'address-PAGE_SIZE'
+ * doesn't hit another vma.
+ *
+ * The "find_vma()" will do the right thing even if we wrap
+ */
+static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned long address)
+{
+	address &= PAGE_MASK;
+	if ((vma->vm_flags & VM_GROWSDOWN) && address == vma->vm_start) {
+		address -= PAGE_SIZE;
+		if (find_vma(vma->vm_mm, address) != vma)
+			return -ENOMEM;
+
+		expand_stack(vma, address);
+	}
+	return 0;
+}
+
+/*
  * We enter with non-exclusive mmap_sem (to exclude vma changes,
  * but allow concurrent faults), and pte mapped but not yet locked.
  * We return with mmap_sem still held, but pte unmapped and unlocked.
@@ -2408,6 +2428,11 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	spinlock_t *ptl;
 	pte_t entry;
 
+	if (check_stack_guard_page(vma, address) < 0) {
+		pte_unmap(page_table);
+		return VM_FAULT_SIGBUS;
+	}
+
 	/* Allocate our own private page. */
 	pte_unmap(page_table);
 
diff --git a/mm/mmap.c b/mm/mmap.c
index f3e5bfe..08a32cf 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1573,7 +1573,7 @@ static int acct_stack_growth(struct vm_area_struct * vma, unsigned long size, un
 	 * Overcommit..  This must be the final test, as it will
 	 * update security statistics.
 	 */
-	if (security_vm_enough_memory(grow))
+	if (security_vm_enough_memory_mm(mm, grow))
 		return -ENOMEM;
 
 	/* Ok, everything looks good - let it rip */