Merge tag 'char-misc-6.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver fixes from Greg KH:
 "Here are some small char/misc and other driver fixes for 6.0-rc4.

  Included in here are:

   - binder fixes for previous fixes, and a few more fixes uncovered by
     them.

   - iio driver fixes

   - soundwire driver fixes

   - fastrpc driver fixes for memory corruption on some hardware

   - peci driver fix

   - mhi driver fix

  All of these have been in linux-next with no reported problems"

* tag 'char-misc-6.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  binder: fix alloc->vma_vm_mm null-ptr dereference
  misc: fastrpc: increase maximum session count
  misc: fastrpc: fix memory corruption on open
  misc: fastrpc: fix memory corruption on probe
  soundwire: qcom: fix device status array range
  bus: mhi: host: Fix up null pointer access in mhi_irq_handler
  soundwire: qcom: remove duplicate reset control get
  iio: light: cm32181: make cm32181_pm_ops static
  iio: ad7292: Prevent regulator double disable
  dt-bindings: iio: gyroscope: bosch,bmg160: correct number of pins
  iio: adc: mcp3911: use correct formula for AD conversion
  iio: adc: mcp3911: correct "microchip,device-addr" property
  Revert "binder_alloc: Add missing mmap_lock calls when using the VMA"
  binder_alloc: Add missing mmap_lock calls when using the VMA
  binder: fix UAF of ref->proc caused by race condition
  iio: light: cm3605: Fix an error handling path in cm3605_probe()
  iio: adc: mcp3911: make use of the sign bit
  peci: cpu: Fix use-after-free in adev_release()
  peci: aspeed: fix error check return value of platform_get_irq()

2 files changed, 14 insertions, 2 deletions

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index c964d7c8c384..6428f6be69e3 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -1385,6 +1385,18 @@ static int binder_inc_ref_for_node(struct binder_proc *proc,
 	}
 	ret = binder_inc_ref_olocked(ref, strong, target_list);
 	*rdata = ref->data;
+	if (ret && ref == new_ref) {
+		/*
+		 * Cleanup the failed reference here as the target
+		 * could now be dead and have already released its
+		 * references by now. Calling on the new reference
+		 * with strong=0 and a tmp_refs will not decrement
+		 * the node. The new_ref gets kfree'd below.
+		 */
+		binder_cleanup_ref_olocked(new_ref);
+		ref = NULL;
+	}
+
 	binder_proc_unlock(proc);
 	if (new_ref && ref != new_ref)
 		/*
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index 51f4e1c5cd01..9b1778c00610 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -322,7 +322,6 @@ static inline void binder_alloc_set_vma(struct binder_alloc *alloc,
 	 */
 	if (vma) {
 		vm_start = vma->vm_start;
-		alloc->vma_vm_mm = vma->vm_mm;
 		mmap_assert_write_locked(alloc->vma_vm_mm);
 	} else {
 		mmap_assert_locked(alloc->vma_vm_mm);
@@ -795,7 +794,6 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 	binder_insert_free_buffer(alloc, buffer);
 	alloc->free_async_space = alloc->buffer_size / 2;
 	binder_alloc_set_vma(alloc, vma);
-	mmgrab(alloc->vma_vm_mm);
 
 	return 0;
 
@@ -1091,6 +1089,8 @@ static struct shrinker binder_shrinker = {
 void binder_alloc_init(struct binder_alloc *alloc)
 {
 	alloc->pid = current->group_leader->pid;
+	alloc->vma_vm_mm = current->mm;
+	mmgrab(alloc->vma_vm_mm);
 	mutex_init(&alloc->mutex);
 	INIT_LIST_HEAD(&alloc->buffers);
 }