From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Tue, 16 Mar 2021 19:59:23 +0000 (-0400)
Subject: sys rcu fix
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=3df109b388de35680fa0ec299419686afb79dde6;p=users%2Fjedix%2Flinux-maple.git

sys rcu fix

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/kernel/sys.c b/kernel/sys.c
index 7f6204c2c86e6..1f1835c177b1d 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1862,6 +1862,7 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
 		MA_STATE(mas, &mm->mm_mt, 0, 0);
 
 		mmap_read_lock(mm);
+		rcu_read_lock();
 		mas_for_each(&mas, vma, ULONG_MAX) {
 			if (!vma->vm_file)
 				continue;
@@ -1870,6 +1871,7 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
 				goto exit_err;
 		}
 
+		rcu_read_unlock();
 		mmap_read_unlock(mm);
 		fput(exe_file);
 	}
@@ -1884,6 +1886,7 @@ exit:
 	fdput(exe);
 	return err;
 exit_err:
+	rcu_read_unlock();
 	mmap_read_unlock(mm);
 	fput(exe_file);
 	goto exit;