Char/Misc fixes for 6.4-rc4

Here are some small driver fixes for 6.4-rc4.  They are just two
 different types:
   - binder fixes and reverts for reported problems and regressions in
     the binder "driver".
   - coresight driver fixes for reported problems.
 
 All of these have been in linux-next for over a week with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-6.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc fixes from Greg KH:
 "Here are some small driver fixes for 6.4-rc4. They are just two
  different types:

   - binder fixes and reverts for reported problems and regressions in
     the binder "driver".

   - coresight driver fixes for reported problems.

  All of these have been in linux-next for over a week with no reported
  problems"

* tag 'char-misc-6.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  binder: fix UAF of alloc->vma in race with munmap()
  binder: add lockless binder_alloc_(set|get)_vma()
  Revert "android: binder: stop saving a pointer to the VMA"
  Revert "binder_alloc: add missing mmap_lock calls when using the VMA"
  binder: fix UAF caused by faulty buffer cleanup
  coresight: perf: Release Coresight path when alloc trace id failed
  coresight: Fix signedness bug in tmc_etr_buf_insert_barrier_packet()

drivers/android/binder.c

@@ -1934,24 +1934,23 @@ static void binder_deferred_fd_close(int fd)
 static void binder_transaction_buffer_release(struct binder_proc *proc,
 					      struct binder_thread *thread,
 					      struct binder_buffer *buffer,
-					      binder_size_t failed_at,
+					      binder_size_t off_end_offset,
 					      bool is_failure)
 {
 	int debug_id = buffer->debug_id;
-	binder_size_t off_start_offset, buffer_offset, off_end_offset;
+	binder_size_t off_start_offset, buffer_offset;
 
 	binder_debug(BINDER_DEBUG_TRANSACTION,
 		     "%d buffer release %d, size %zd-%zd, failed at %llx\n",
 		     proc->pid, buffer->debug_id,
 		     buffer->data_size, buffer->offsets_size,
-		     (unsigned long long)failed_at);
+		     (unsigned long long)off_end_offset);
 
 	if (buffer->target_node)
 		binder_dec_node(buffer->target_node, 1, 0);
 
 	off_start_offset = ALIGN(buffer->data_size, sizeof(void *));
-	off_end_offset = is_failure && failed_at ? failed_at :
-				off_start_offset + buffer->offsets_size;
+
 	for (buffer_offset = off_start_offset; buffer_offset < off_end_offset;
 	     buffer_offset += sizeof(binder_size_t)) {
 		struct binder_object_header *hdr;
@@ -2111,6 +2110,21 @@ static void binder_transaction_buffer_release(struct binder_proc *proc,
 	}
 }
 
+/* Clean up all the objects in the buffer */
+static inline void binder_release_entire_buffer(struct binder_proc *proc,
+						struct binder_thread *thread,
+						struct binder_buffer *buffer,
+						bool is_failure)
+{
+	binder_size_t off_end_offset;
+
+	off_end_offset = ALIGN(buffer->data_size, sizeof(void *));
+	off_end_offset += buffer->offsets_size;
+
+	binder_transaction_buffer_release(proc, thread, buffer,
+					  off_end_offset, is_failure);
+}
+
 static int binder_translate_binder(struct flat_binder_object *fp,
 				   struct binder_transaction *t,
 				   struct binder_thread *thread)
@@ -2806,7 +2820,7 @@ static int binder_proc_transaction(struct binder_transaction *t,
 		t_outdated->buffer = NULL;
 		buffer->transaction = NULL;
 		trace_binder_transaction_update_buffer_release(buffer);
-		binder_transaction_buffer_release(proc, NULL, buffer, 0, 0);
+		binder_release_entire_buffer(proc, NULL, buffer, false);
 		binder_alloc_free_buf(&proc->alloc, buffer);
 		kfree(t_outdated);
 		binder_stats_deleted(BINDER_STAT_TRANSACTION);
@@ -3775,7 +3789,7 @@ binder_free_buf(struct binder_proc *proc,
 		binder_node_inner_unlock(buf_node);
 	}
 	trace_binder_transaction_buffer_release(buffer);
-	binder_transaction_buffer_release(proc, thread, buffer, 0, is_failure);
+	binder_release_entire_buffer(proc, thread, buffer, is_failure);
 	binder_alloc_free_buf(&proc->alloc, buffer);
 }
 

drivers/android/binder_alloc.c

@@ -212,8 +212,8 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
 		mm = alloc->mm;
 
 	if (mm) {
-		mmap_read_lock(mm);
-		vma = vma_lookup(mm, alloc->vma_addr);
+		mmap_write_lock(mm);
+		vma = alloc->vma;
 	}
 
 	if (!vma && need_mm) {
@@ -270,7 +270,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
 		trace_binder_alloc_page_end(alloc, index);
 	}
 	if (mm) {
-		mmap_read_unlock(mm);
+		mmap_write_unlock(mm);
 		mmput(mm);
 	}
 	return 0;
@@ -303,21 +303,24 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
 	}
 err_no_vma:
 	if (mm) {
-		mmap_read_unlock(mm);
+		mmap_write_unlock(mm);
 		mmput(mm);
 	}
 	return vma ? -ENOMEM : -ESRCH;
 }
 
+static inline void binder_alloc_set_vma(struct binder_alloc *alloc,
+		struct vm_area_struct *vma)
+{
+	/* pairs with smp_load_acquire in binder_alloc_get_vma() */
+	smp_store_release(&alloc->vma, vma);
+}
+
 static inline struct vm_area_struct *binder_alloc_get_vma(
 		struct binder_alloc *alloc)
 {
-	struct vm_area_struct *vma = NULL;
-
-	if (alloc->vma_addr)
-		vma = vma_lookup(alloc->mm, alloc->vma_addr);
-
-	return vma;
+	/* pairs with smp_store_release in binder_alloc_set_vma() */
+	return smp_load_acquire(&alloc->vma);
 }
 
 static bool debug_low_async_space_locked(struct binder_alloc *alloc, int pid)
@@ -380,15 +383,13 @@ static struct binder_buffer *binder_alloc_new_buf_locked(
 	size_t size, data_offsets_size;
 	int ret;
 
-	mmap_read_lock(alloc->mm);
+	/* Check binder_alloc is fully initialized */
 	if (!binder_alloc_get_vma(alloc)) {
-		mmap_read_unlock(alloc->mm);
 		binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
 				   "%d: binder_alloc_buf, no vma\n",
 				   alloc->pid);
 		return ERR_PTR(-ESRCH);
 	}
-	mmap_read_unlock(alloc->mm);
 
 	data_offsets_size = ALIGN(data_size, sizeof(void *)) +
 		ALIGN(offsets_size, sizeof(void *));
@@ -778,7 +779,9 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 	buffer->free = 1;
 	binder_insert_free_buffer(alloc, buffer);
 	alloc->free_async_space = alloc->buffer_size / 2;
-	alloc->vma_addr = vma->vm_start;
+
+	/* Signal binder_alloc is fully initialized */
+	binder_alloc_set_vma(alloc, vma);
 
 	return 0;
 
@@ -808,8 +811,7 @@ void binder_alloc_deferred_release(struct binder_alloc *alloc)
 
 	buffers = 0;
 	mutex_lock(&alloc->mutex);
-	BUG_ON(alloc->vma_addr &&
-	       vma_lookup(alloc->mm, alloc->vma_addr));
+	BUG_ON(alloc->vma);
 
 	while ((n = rb_first(&alloc->allocated_buffers))) {
 		buffer = rb_entry(n, struct binder_buffer, rb_node);
@@ -916,25 +918,17 @@ void binder_alloc_print_pages(struct seq_file *m,
 	 * Make sure the binder_alloc is fully initialized, otherwise we might
 	 * read inconsistent state.
 	 */
-
-	mmap_read_lock(alloc->mm);
-	if (binder_alloc_get_vma(alloc) == NULL) {
-		mmap_read_unlock(alloc->mm);
-		goto uninitialized;
+	if (binder_alloc_get_vma(alloc) != NULL) {
+		for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
+			page = &alloc->pages[i];
+			if (!page->page_ptr)
+				free++;
+			else if (list_empty(&page->lru))
+				active++;
+			else
+				lru++;
+		}
 	}
-
-	mmap_read_unlock(alloc->mm);
-	for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
-		page = &alloc->pages[i];
-		if (!page->page_ptr)
-			free++;
-		else if (list_empty(&page->lru))
-			active++;
-		else
-			lru++;
-	}
-
-uninitialized:
 	mutex_unlock(&alloc->mutex);
 	seq_printf(m, "  pages: %d:%d:%d\n", active, lru, free);
 	seq_printf(m, "  pages high watermark: %zu\n", alloc->pages_high);
@@ -969,7 +963,7 @@ int binder_alloc_get_allocated_count(struct binder_alloc *alloc)
  */
 void binder_alloc_vma_close(struct binder_alloc *alloc)
 {
-	alloc->vma_addr = 0;
+	binder_alloc_set_vma(alloc, NULL);
 }
 
 /**

drivers/android/binder_alloc.h

@@ -75,7 +75,7 @@ struct binder_lru_page {
 /**
  * struct binder_alloc - per-binder proc state for binder allocator
  * @mutex:              protects binder_alloc fields
- * @vma_addr:           vm_area_struct->vm_start passed to mmap_handler
+ * @vma:                vm_area_struct passed to mmap_handler
  *                      (invariant after mmap)
  * @mm:                 copy of task->mm (invariant after open)
  * @buffer:             base of per-proc address space mapped via mmap
@@ -99,7 +99,7 @@ struct binder_lru_page {
  */
 struct binder_alloc {
 	struct mutex mutex;
-	unsigned long vma_addr;
+	struct vm_area_struct *vma;
 	struct mm_struct *mm;
 	void __user *buffer;
 	struct list_head buffers;

drivers/android/binder_alloc_selftest.c

@@ -287,7 +287,7 @@ void binder_selftest_alloc(struct binder_alloc *alloc)
 	if (!binder_selftest_run)
 		return;
 	mutex_lock(&binder_selftest_lock);
-	if (!binder_selftest_run || !alloc->vma_addr)
+	if (!binder_selftest_run || !alloc->vma)
 		goto done;
 	pr_info("STARTED\n");
 	binder_selftest_alloc_offset(alloc, end_offset, 0);

drivers/hwtracing/coresight/coresight-etm-perf.c

@@ -402,6 +402,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
 		trace_id = coresight_trace_id_get_cpu_id(cpu);
 		if (!IS_VALID_CS_TRACE_ID(trace_id)) {
 			cpumask_clear_cpu(cpu, mask);
+			coresight_release_path(path);
 			continue;
 		}
 

drivers/hwtracing/coresight/coresight-tmc-etr.c

@@ -942,7 +942,7 @@ tmc_etr_buf_insert_barrier_packet(struct etr_buf *etr_buf, u64 offset)
 
 	len = tmc_etr_buf_get_data(etr_buf, offset,
 				   CORESIGHT_BARRIER_PKT_SIZE, &bufp);
-	if (WARN_ON(len < CORESIGHT_BARRIER_PKT_SIZE))
+	if (WARN_ON(len < 0 || len < CORESIGHT_BARRIER_PKT_SIZE))
 		return -EINVAL;
 	coresight_insert_barrier_packet(bufp);
 	return offset + CORESIGHT_BARRIER_PKT_SIZE;