patches/old/secretmem-fix-unhandled-fault-in-truncate-v3.patch

From: Mike Rapoport <rppt@linux.ibm.com>
Subject: secretmem: fix unhandled fault in truncate
Date: Thu, 14 Jul 2022 12:13:37 +0300

v3: use invalidate_lock rather than inode_lock
v2: use inode_lock_shared() rather than add a new rw_sem to secretmem

Link: https://lkml.kernel.org/r/20220714091337.412297-1-rppt@kernel.org
Reported-by: syzbot+9bd2b7adbd34b30b87e4@syzkaller.appspotmail.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Suggested-by: Eric Biggers <ebiggers@kernel.org>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/secretmem.c |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

--- a/mm/secretmem.c~secretmem-fix-unhandled-fault-in-truncate-v3
+++ a/mm/secretmem.c
@@ -61,7 +61,7 @@ static vm_fault_t secretmem_fault(struct
 	if (((loff_t)vmf->pgoff << PAGE_SHIFT) >= i_size_read(inode))
 		return vmf_error(-EINVAL);
 
-	inode_lock_shared(inode);
+	filemap_invalidate_lock_shared(mapping);
 
 retry:
 	page = find_lock_page(mapping, offset);
@@ -104,7 +104,7 @@ retry:
 	ret = VM_FAULT_LOCKED;
 
 out:
-	inode_unlock_shared(inode);
+	filemap_invalidate_unlock_shared(mapping);
 	return ret;
 }
 
@@ -173,12 +173,20 @@ static int secretmem_setattr(struct user
 			     struct dentry *dentry, struct iattr *iattr)
 {
 	struct inode *inode = d_inode(dentry);
+	struct address_space *mapping = inode->i_mapping;
 	unsigned int ia_valid = iattr->ia_valid;
+	int ret;
+
+	filemap_invalidate_lock(mapping);
 
 	if ((ia_valid & ATTR_SIZE) && inode->i_size)
-		return -EINVAL;
+		ret = -EINVAL;
+	else
+		ret = simple_setattr(mnt_userns, dentry, iattr);
 
-	return simple_setattr(mnt_userns, dentry, iattr);
+	filemap_invalidate_unlock(mapping);
+
+	return ret;
 }
 
 static const struct inode_operations secretmem_iops = {
_