[PATCH AUTOSEL 5.15 2/6] hfs: Sanity check the root record

[PATCH AUTOSEL 5.15 2/6] hfs: Sanity check the root record

[Sasha Levin]

From: Leo Stone <leocstone@gmail.com>

[ Upstream commit b905bafdea21a75d75a96855edd9e0b6051eee30 ]

In the syzbot reproducer, the hfs_cat_rec for the root dir has type
HFS_CDR_FIL after being read with hfs_bnode_read() in hfs_super_fill().
This indicates it should be used as an hfs_cat_file, which is 102 bytes.
Only the first 70 bytes of that struct are initialized, however,
because the entrylength passed into hfs_bnode_read() is still the length of
a directory record. This causes uninitialized values to be used later on,
when the hfs_cat_rec union is treated as the larger hfs_cat_file struct.

Add a check to make sure the retrieved record has the correct type
for the root directory (HFS_CDR_DIR), and make sure we load the correct
number of bytes for a directory record.

Reported-by: syzbot+2db3c7526ba68f4ea776@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=2db3c7526ba68f4ea776
Tested-by: syzbot+2db3c7526ba68f4ea776@syzkaller.appspotmail.com
Tested-by: Leo Stone <leocstone@gmail.com>
Signed-off-by: Leo Stone <leocstone@gmail.com>
Link: https://lore.kernel.org/r/20241201051420.77858-1-leocstone@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/hfs/super.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index 12d9bae39363..699dd94b1a86 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c
@@ -418,11 +418,13 @@ static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 		goto bail_no_root;
 	res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
 	if (!res) {
-		if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
+		if (fd.entrylength != sizeof(rec.dir)) {
 			res =  -EIO;
 			goto bail_hfs_find;
 		}
 		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
+		if (rec.type != HFS_CDR_DIR)
+			res = -EIO;
 	}
 	if (res)
 		goto bail_hfs_find;
-- 
2.39.5

[PATCH AUTOSEL 5.15 3/6] fs: fix missing declaration of init_files

[Sasha Levin]

From: Zhang Kunbo <zhangkunbo@huawei.com>

[ Upstream commit 2b2fc0be98a828cf33a88a28e9745e8599fb05cf ]

fs/file.c should include include/linux/init_task.h  for
 declaration of init_files. This fixes the sparse warning:

fs/file.c:501:21: warning: symbol 'init_files' was not declared. Should it be static?

Signed-off-by: Zhang Kunbo <zhangkunbo@huawei.com>
Link: https://lore.kernel.org/r/20241217071836.2634868-1-zhangkunbo@huawei.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/file.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/file.c b/fs/file.c
index b4194ee5c4d4..386968003030 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -21,6 +21,7 @@
 #include <linux/rcupdate.h>
 #include <linux/close_range.h>
 #include <net/sock.h>
+#include <linux/init_task.h>
 
 #include "internal.h"
 
-- 
2.39.5