f2fs: fix to do sanity check on blocks for inline_data inode

BugLink: https://bugs.launchpad.net/bugs/2084941

[ Upstream commit c240c87bcd44a1a2375fc8ef8c645d1f1fe76466 ]

inode can be fuzzed, so it can has F2FS_INLINE_DATA flag and valid
i_blocks/i_nid value, this patch supports to do extra sanity check
to detect such corrupted state.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Manuel Diewald <manuel.diewald@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

fs/f2fs/f2fs.h

@@ -4158,7 +4158,7 @@ extern struct kmem_cache *f2fs_inode_entry_slab;
  * inline.c
  */
 bool f2fs_may_inline_data(struct inode *inode);
-bool f2fs_sanity_check_inline_data(struct inode *inode);
+bool f2fs_sanity_check_inline_data(struct inode *inode, struct page *ipage);
 bool f2fs_may_inline_dentry(struct inode *inode);
 void f2fs_do_read_inline_data(struct page *page, struct page *ipage);
 void f2fs_truncate_inline_inode(struct inode *inode,

fs/f2fs/inline.c

@@ -33,11 +33,29 @@ bool f2fs_may_inline_data(struct inode *inode)
 	return !f2fs_post_read_required(inode);
 }
 
-bool f2fs_sanity_check_inline_data(struct inode *inode)
+static bool inode_has_blocks(struct inode *inode, struct page *ipage)
+{
+	struct f2fs_inode *ri = F2FS_INODE(ipage);
+	int i;
+
+	if (F2FS_HAS_BLOCKS(inode))
+		return true;
+
+	for (i = 0; i < DEF_NIDS_PER_INODE; i++) {
+		if (ri->i_nid[i])
+			return true;
+	}
+	return false;
+}
+
+bool f2fs_sanity_check_inline_data(struct inode *inode, struct page *ipage)
 {
 	if (!f2fs_has_inline_data(inode))
 		return false;
 
+	if (inode_has_blocks(inode, ipage))
+		return false;
+
 	if (!support_inline_data(inode))
 		return true;
 

fs/f2fs/inode.c

@@ -346,7 +346,7 @@ static bool sanity_check_inode(struct inode *inode, struct page *node_page)
 		}
 	}
 
-	if (f2fs_sanity_check_inline_data(inode)) {
+	if (f2fs_sanity_check_inline_data(inode, node_page)) {
 		f2fs_warn(sbi, "%s: inode (ino=%lx, mode=%u) should not have inline_data, run fsck to fix",
 			  __func__, inode->i_ino, inode->i_mode);
 		return false;