Commit f16864a7 authored by Luo Gengkun's avatar Luo Gengkun
Browse files

perf: Fix kabi problem by put mutex in front of perf_buffer 

HULK inclusion
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAR9C1


CVE: CVE-2024-46713

--------------------------------

To fix kabi breakage, put the mutex in front of perf_buffer.

Fixes: 45bfb2e5 ("perf/aux: Fix AUX buffer serialization")
Signed-off-by: default avatarLuo Gengkun <luogengkun2@huawei.com>
parent a765a932

kernel/events/core.c

+6 −3
Original line number Diff line number Diff line
@@ -6356,6 +6356,7 @@ static void perf_mmap_close(struct vm_area_struct *vma) 
	int mmap_locked = rb->mmap_locked;

	unsigned long size = perf_data_size(rb);

	bool detach_rest = false;

	struct perf_buffer_ext *rb_ext = container_of(rb, struct perf_buffer_ext, perf_buffer);



	if (event->pmu->event_unmapped)

		event->pmu->event_unmapped(event, vma->vm_mm);
@@ -6365,7 +6366,7 @@ static void perf_mmap_close(struct vm_area_struct *vma) 
	 * to avoid complications.

	 */

	if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff &&

	    atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &rb->aux_mutex)) {

	    atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &rb_ext->aux_mutex)) {

		/*

		 * Stop all AUX events that are writing to this buffer,

		 * so that we can free its AUX pages and corresponding PMU
@@ -6382,7 +6383,7 @@ static void perf_mmap_close(struct vm_area_struct *vma) 
		rb_free_aux(rb);

		WARN_ON_ONCE(refcount_read(&rb->aux_refcount));



		mutex_unlock(&rb->aux_mutex);

		mutex_unlock(&rb_ext->aux_mutex);

	}



	if (atomic_dec_and_test(&rb->mmap_count))
@@ -6472,6 +6473,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) 
	struct user_struct *user = current_user();

	struct mutex *aux_mutex = NULL;

	struct perf_buffer *rb = NULL;

	struct perf_buffer_ext *rb_ext = NULL;

	unsigned long locked, lock_limit;

	unsigned long vma_size;

	unsigned long nr_pages;
@@ -6519,7 +6521,8 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) 
		if (!rb)

			goto aux_unlock;



		aux_mutex = &rb->aux_mutex;

		rb_ext = container_of(rb, struct perf_buffer_ext, perf_buffer);

		aux_mutex = &rb_ext->aux_mutex;

		mutex_lock(aux_mutex);



		aux_offset = READ_ONCE(rb->user_page->aux_offset);

kernel/events/internal.h

+5 −1
Original line number Diff line number Diff line
@@ -40,7 +40,6 @@ struct perf_buffer { 
	struct user_struct		*mmap_user;



	/* AUX area */

	struct mutex			aux_mutex;

	long				aux_head;

	unsigned int			aux_nest;

	long				aux_wakeup;	/* last aux_watermark boundary crossed by aux_head */
@@ -59,6 +58,11 @@ struct perf_buffer { 
	void				*data_pages[];

};



struct perf_buffer_ext {

	struct mutex		aux_mutex;

	struct perf_buffer	perf_buffer;

};



extern void rb_free(struct perf_buffer *rb);



static inline void rb_free_rcu(struct rcu_head *rcu_head)

kernel/events/ring_buffer.c

+19 −11
Original line number Diff line number Diff line
@@ -310,6 +310,7 @@ static void 
ring_buffer_init(struct perf_buffer *rb, long watermark, int flags)

{

	long max_size = perf_data_size(rb);

	struct perf_buffer_ext *rb_ext = container_of(rb, struct perf_buffer_ext, perf_buffer);



	if (watermark)

		rb->watermark = min(max_size, watermark);
@@ -334,7 +335,7 @@ ring_buffer_init(struct perf_buffer *rb, long watermark, int flags) 
	if (!rb->nr_pages)

		rb->paused = 1;



	mutex_init(&rb->aux_mutex);

	mutex_init(&rb_ext->aux_mutex);

}



void perf_aux_output_flag(struct perf_output_handle *handle, u64 flags)
@@ -818,21 +819,23 @@ static void perf_mmap_free_page(void *addr) 


struct perf_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)

{

	struct perf_buffer_ext *rb_ext;

	struct perf_buffer *rb;

	unsigned long size;

	int i, node;



	size = sizeof(struct perf_buffer);

	size = sizeof(struct perf_buffer_ext);

	size += nr_pages * sizeof(void *);



	if (order_base_2(size) > PAGE_SHIFT+MAX_ORDER)

		goto fail;



	node = (cpu == -1) ? cpu : cpu_to_node(cpu);

	rb = kzalloc_node(size, GFP_KERNEL, node);

	if (!rb)

	rb_ext = kzalloc_node(size, GFP_KERNEL, node);

	if (!rb_ext)

		goto fail;



	rb = &rb_ext->perf_buffer;

	rb->user_page = perf_mmap_alloc_page(cpu);

	if (!rb->user_page)

		goto fail_user_page;
@@ -856,7 +859,7 @@ struct perf_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags) 
	perf_mmap_free_page(rb->user_page);



fail_user_page:

	kfree(rb);

	kfree(rb_ext);



fail:

	return NULL;
@@ -865,11 +868,12 @@ struct perf_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags) 
void rb_free(struct perf_buffer *rb)

{

	int i;

	struct perf_buffer_ext *rb_ext = container_of(rb, struct perf_buffer_ext, perf_buffer);



	perf_mmap_free_page(rb->user_page);

	for (i = 0; i < rb->nr_pages; i++)

		perf_mmap_free_page(rb->data_pages[i]);

	kfree(rb);

	kfree(rb_ext);

}



#else
@@ -892,6 +896,7 @@ static void perf_mmap_unmark_page(void *addr) 


static void rb_free_work(struct work_struct *work)

{

	struct perf_buffer_ext *rb_ext;

	struct perf_buffer *rb;

	void *base;

	int i, nr;
@@ -905,7 +910,8 @@ static void rb_free_work(struct work_struct *work) 
		perf_mmap_unmark_page(base + (i * PAGE_SIZE));



	vfree(base);

	kfree(rb);

	rb_ext = container_of(rb, struct perf_buffer_ext, perf_buffer);

	kfree(rb_ext);

}



void rb_free(struct perf_buffer *rb)
@@ -915,19 +921,21 @@ void rb_free(struct perf_buffer *rb) 


struct perf_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)

{

	struct perf_buffer_ext *rb_ext;

	struct perf_buffer *rb;

	unsigned long size;

	void *all_buf;

	int node;



	size = sizeof(struct perf_buffer);

	size = sizeof(struct perf_buffer_ext);

	size += sizeof(void *);



	node = (cpu == -1) ? cpu : cpu_to_node(cpu);

	rb = kzalloc_node(size, GFP_KERNEL, node);

	if (!rb)

	rb_ext = kzalloc_node(size, GFP_KERNEL, node);

	if (!rb_ext)

		goto fail;



	rb = &rb_ext->perf_buffer;

	INIT_WORK(&rb->work, rb_free_work);



	all_buf = vmalloc_user((nr_pages + 1) * PAGE_SIZE);
@@ -946,7 +954,7 @@ struct perf_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags) 
	return rb;



fail_all_buf:

	kfree(rb);

	kfree(rb_ext);



fail:

	return NULL;