From 137c838f177b86797a9a805bb131e0f96cdac565 Mon Sep 17 00:00:00 2001 From: Todd Kjos Date: Wed, 5 Jun 2019 09:38:24 -0700 Subject: [PATCH] Revert "binder: fix handling of misaligned binder object" This reverts commit 6bf7d3c5c0c5dad650bfc4345ed553c18b69d59e. The commit message is for a different patch. Reverting and then adding the same patch back with the correct commit message. Reported-by: Ben Hutchings Cc: stable # 4.19 Signed-off-by: Todd Kjos Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder_alloc.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index a654ccf..030c98f 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -958,13 +958,14 @@ enum lru_status binder_alloc_free_page(struct list_head *item, index = page - alloc->pages; page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE; - - mm = alloc->vma_vm_mm; - if (!mmget_not_zero(mm)) - goto err_mmget; - if (!down_write_trylock(&mm->mmap_sem)) - goto err_down_write_mmap_sem_failed; vma = binder_alloc_get_vma(alloc); + if (vma) { + if (!mmget_not_zero(alloc->vma_vm_mm)) + goto err_mmget; + mm = alloc->vma_vm_mm; + if (!down_write_trylock(&mm->mmap_sem)) + goto err_down_write_mmap_sem_failed; + } list_lru_isolate(lru, item); spin_unlock(lock); @@ -977,9 +978,10 @@ enum lru_status binder_alloc_free_page(struct list_head *item, PAGE_SIZE); trace_binder_unmap_user_end(alloc, index); + + up_write(&mm->mmap_sem); + mmput(mm); } - up_write(&mm->mmap_sem); - mmput(mm); trace_binder_unmap_kernel_start(alloc, index); -- 2.7.4