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-rw-r--r--arch/x86/kernel/kprobes/core.c5
-rw-r--r--include/linux/kasan.h2
-rw-r--r--mm/kasan/kasan.c22
3 files changed, 25 insertions, 4 deletions
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 99d293ea2b49..3eb804335458 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -49,7 +49,7 @@
#include <linux/kdebug.h>
#include <linux/kallsyms.h>
#include <linux/ftrace.h>
-
+#include <linux/kasan.h>
#include <asm/cacheflush.h>
#include <asm/desc.h>
#include <asm/pgtable.h>
@@ -1078,6 +1078,9 @@ void jprobe_return(void)
{
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ /* Unpoison stack redzones in the frames we are going to jump over. */
+ kasan_unpoison_stack_above_sp_to(kcb->jprobe_saved_sp);
+
asm volatile (
#ifdef CONFIG_X86_64
" xchg %%rbx,%%rsp \n"
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index d600303306eb..820c0ad54a01 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -44,6 +44,7 @@ static inline void kasan_disable_current(void)
void kasan_unpoison_shadow(const void *address, size_t size);
void kasan_unpoison_task_stack(struct task_struct *task);
+void kasan_unpoison_stack_above_sp_to(const void *watermark);
void kasan_alloc_pages(struct page *page, unsigned int order);
void kasan_free_pages(struct page *page, unsigned int order);
@@ -85,6 +86,7 @@ size_t kasan_metadata_size(struct kmem_cache *cache);
static inline void kasan_unpoison_shadow(const void *address, size_t size) {}
static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
+static inline void kasan_unpoison_stack_above_sp_to(const void *watermark) {}
static inline void kasan_enable_current(void) {}
static inline void kasan_disable_current(void) {}
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 88af13c00d3c..70c009741aab 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -34,6 +34,7 @@
#include <linux/string.h>
#include <linux/types.h>
#include <linux/vmalloc.h>
+#include <linux/bug.h>
#include "kasan.h"
#include "../slab.h"
@@ -62,7 +63,7 @@ void kasan_unpoison_shadow(const void *address, size_t size)
}
}
-static void __kasan_unpoison_stack(struct task_struct *task, void *sp)
+static void __kasan_unpoison_stack(struct task_struct *task, const void *sp)
{
void *base = task_stack_page(task);
size_t size = sp - base;
@@ -77,9 +78,24 @@ void kasan_unpoison_task_stack(struct task_struct *task)
}
/* Unpoison the stack for the current task beyond a watermark sp value. */
-asmlinkage void kasan_unpoison_remaining_stack(void *sp)
+asmlinkage void kasan_unpoison_task_stack_below(const void *watermark)
{
- __kasan_unpoison_stack(current, sp);
+ __kasan_unpoison_stack(current, watermark);
+}
+
+/*
+ * Clear all poison for the region between the current SP and a provided
+ * watermark value, as is sometimes required prior to hand-crafted asm function
+ * returns in the middle of functions.
+ */
+void kasan_unpoison_stack_above_sp_to(const void *watermark)
+{
+ const void *sp = __builtin_frame_address(0);
+ size_t size = watermark - sp;
+
+ if (WARN_ON(sp > watermark))
+ return;
+ kasan_unpoison_shadow(sp, size);
}
/*