From 3d18d86ea94542beb0e211d0f68b56c10e2e92b3 Mon Sep 17 00:00:00 2001 From: Suren Baghdasaryan Date: Mon, 27 Feb 2023 09:36:19 -0800 Subject: [PATCH] UPSTREAM: kernel/fork: assert no VMA readers during its destruction Assert there are no holders of VMA lock for reading when it is about to be destroyed. Link: https://lkml.kernel.org/r/20230227173632.3292573-21-surenb@google.com Signed-off-by: Suren Baghdasaryan Signed-off-by: Andrew Morton (cherry picked from commit f2e13784c16a98e269b3111ac02ae44446dd589c) Bug: 161210518 Change-Id: I67fc318fd08575c9bcc54fd00b0304246b0cd279 Signed-off-by: Suren Baghdasaryan --- kernel/fork.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/fork.c b/kernel/fork.c index 989dd01c61c1..5fdc0df905ee 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -498,6 +498,9 @@ static void vm_area_free_rcu_cb(struct rcu_head *head) { struct vm_area_struct *vma = container_of(head, struct vm_area_struct, vm_rcu); + + /* The vma should not be locked while being destroyed. */ + VM_BUG_ON_VMA(rwsem_is_locked(&vma->lock), vma); __vm_area_free(vma); } #endif