[PATCH AUTOSEL 4.19] fs: hfsplus: remove WARN_ON() from hfsplus_cat_{read,write}_inode()

[Sasha Levin <sashal@xxxxxxxxxx>]

From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>

[ Upstream commit 81b21c0f0138ff5a499eafc3eb0578ad2a99622c ]

syzbot is hitting WARN_ON() in hfsplus_cat_{read,write}_inode(), for
crafted filesystem image can contain bogus length. There conditions are
not kernel bugs that can justify kernel to panic.

Reported-by: syzbot <syzbot+e2787430e752a92b8750@xxxxxxxxxxxxxxxxxxxxxxxxx>
Link: https://syzkaller.appspot.com/bug?extid=e2787430e752a92b8750
Reported-by: syzbot <syzbot+4913dca2ea6e4d43f3f1@xxxxxxxxxxxxxxxxxxxxxxxxx>
Link: https://syzkaller.appspot.com/bug?extid=4913dca2ea6e4d43f3f1
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Viacheslav Dubeyko <slava@xxxxxxxxxxx>
Message-Id: <15308173-5252-d6a3-ae3b-e96d46cb6f41@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/hfsplus/inode.c | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index c7073a1517d68..a1d4ad584b105 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -476,7 +476,11 @@ int hfsplus_cat_read_inode(struct inode *inode, struct hfs_find_data *fd)
 	if (type == HFSPLUS_FOLDER) {
 		struct hfsplus_cat_folder *folder = &entry.folder;
 
-		WARN_ON(fd->entrylength < sizeof(struct hfsplus_cat_folder));
+		if (fd->entrylength < sizeof(struct hfsplus_cat_folder)) {
+			pr_err("bad catalog folder entry\n");
+			res = -EIO;
+			goto out;
+		}
 		hfs_bnode_read(fd->bnode, &entry, fd->entryoffset,
 					sizeof(struct hfsplus_cat_folder));
 		hfsplus_get_perms(inode, &folder->permissions, 1);
@@ -496,7 +500,11 @@ int hfsplus_cat_read_inode(struct inode *inode, struct hfs_find_data *fd)
 	} else if (type == HFSPLUS_FILE) {
 		struct hfsplus_cat_file *file = &entry.file;
 
-		WARN_ON(fd->entrylength < sizeof(struct hfsplus_cat_file));
+		if (fd->entrylength < sizeof(struct hfsplus_cat_file)) {
+			pr_err("bad catalog file entry\n");
+			res = -EIO;
+			goto out;
+		}
 		hfs_bnode_read(fd->bnode, &entry, fd->entryoffset,
 					sizeof(struct hfsplus_cat_file));
 
@@ -527,6 +535,7 @@ int hfsplus_cat_read_inode(struct inode *inode, struct hfs_find_data *fd)
 		pr_err("bad catalog entry used to create inode\n");
 		res = -EIO;
 	}
+out:
 	return res;
 }
 
@@ -535,6 +544,7 @@ int hfsplus_cat_write_inode(struct inode *inode)
 	struct inode *main_inode = inode;
 	struct hfs_find_data fd;
 	hfsplus_cat_entry entry;
+	int res = 0;
 
 	if (HFSPLUS_IS_RSRC(inode))
 		main_inode = HFSPLUS_I(inode)->rsrc_inode;
@@ -553,7 +563,11 @@ int hfsplus_cat_write_inode(struct inode *inode)
 	if (S_ISDIR(main_inode->i_mode)) {
 		struct hfsplus_cat_folder *folder = &entry.folder;
 
-		WARN_ON(fd.entrylength < sizeof(struct hfsplus_cat_folder));
+		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
+			pr_err("bad catalog folder entry\n");
+			res = -EIO;
+			goto out;
+		}
 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
 					sizeof(struct hfsplus_cat_folder));
 		/* simple node checks? */
@@ -578,7 +592,11 @@ int hfsplus_cat_write_inode(struct inode *inode)
 	} else {
 		struct hfsplus_cat_file *file = &entry.file;
 
-		WARN_ON(fd.entrylength < sizeof(struct hfsplus_cat_file));
+		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
+			pr_err("bad catalog file entry\n");
+			res = -EIO;
+			goto out;
+		}
 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
 					sizeof(struct hfsplus_cat_file));
 		hfsplus_inode_write_fork(inode, &file->data_fork);
@@ -599,5 +617,5 @@ int hfsplus_cat_write_inode(struct inode *inode)
 	set_bit(HFSPLUS_I_CAT_DIRTY, &HFSPLUS_I(inode)->flags);
 out:
 	hfs_find_exit(&fd);
-	return 0;
+	return res;
 }
-- 
2.39.2