From: Max Filippov <jcmvbkbc@gmail.com>
Date: Sat, 1 Jul 2023 10:31:55 +0000 (-0700)
Subject: xtensa: fix lock_mm_and_find_vma in case VMA not found
X-Git-Tag: v6.3.12~13
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=af6410c8f7c41ce25c02dc190499f0944ec29499;p=thirdparty%2Fkernel%2Fstable.git

xtensa: fix lock_mm_and_find_vma in case VMA not found

commit 03f889378f33aa9a9d8e5f49ba94134cf6158090 upstream.

MMU version of lock_mm_and_find_vma releases the mm lock before
returning when VMA is not found. Do the same in noMMU version.
This fixes hang on an attempt to handle protection fault.

Fixes: d85a143b69ab ("xtensa: fix NOMMU build with lock_mm_and_find_vma() conversion")
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/mm/nommu.c b/mm/nommu.c
index 07a3af6a94ea8..4e0c28644ffa0 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -637,8 +637,13 @@ EXPORT_SYMBOL(find_vma);
 struct vm_area_struct *lock_mm_and_find_vma(struct mm_struct *mm,
 			unsigned long addr, struct pt_regs *regs)
 {
+	struct vm_area_struct *vma;
+
 	mmap_read_lock(mm);
-	return vma_lookup(mm, addr);
+	vma = vma_lookup(mm, addr);
+	if (!vma)
+		mmap_read_unlock(mm);
+	return vma;
 }
 
 /*