To prevent inodes with invalid file types from tripping through the
vfs and causing malfunctions or assertion failures, add a missing
sanity check when reading an inode from a block device. If the file
type is not valid, treat it as a filesystem error.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+895c23f6917da440ed0d@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d
Cc: stable@vger.kernel.org
Fixes: 05fe58fdc10d ("nilfs2: inode operations")
---
Hi Andrew, please apply this as a bug fix.
This fixes a missing check in nilfs2 that could allow invalid file
types to be imported from corrupted filesystem images, as reported by
syzbot following a recently added VFS assertion.
Thanks,
Ryusuke Konishi
fs/nilfs2/inode.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 6613b8fcceb0..5cf7328d5360 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -472,11 +472,18 @@ static int __nilfs_read_inode(struct super_block *sb,
inode->i_op = &nilfs_symlink_inode_operations;
inode_nohighmem(inode);
inode->i_mapping->a_ops = &nilfs_aops;
- } else {
+ } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
+ S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
inode->i_op = &nilfs_special_inode_operations;
init_special_inode(
inode, inode->i_mode,
huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
+ } else {
+ nilfs_error(sb,
+ "invalid file type bits in mode 0%o for inode %lu",
+ inode->i_mode, ino);
+ err = -EIO;
+ goto failed_unmap;
}
nilfs_ifile_unmap_inode(raw_inode);
brelse(bh);
--
2.43.0