[4.14,036/210] nilfs2: fix NULL pointer dereference at nilfs_bmap_lookup_at_level()
Commit Message
Greg KH
Oct. 24, 2022, 11:29 a.m. UTC
From: Ryusuke Konishi <konishi.ryusuke@gmail.com> commit 21a87d88c2253350e115029f14fe2a10a7e6c856 upstream. If the i_mode field in inode of metadata files is corrupted on disk, it can cause the initialization of bmap structure, which should have been called from nilfs_read_inode_common(), not to be called. This causes a lockdep warning followed by a NULL pointer dereference at nilfs_bmap_lookup_at_level(). This patch fixes these issues by adding a missing sanitiy check for the i_mode field of metadata file's inode. Link: https://lkml.kernel.org/r/20221002030804.29978-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+2b32eb36c1a825b7a74c@syzkaller.appspotmail.com Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- fs/nilfs2/inode.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -455,6 +455,8 @@ int nilfs_read_inode_common(struct inode inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec); inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec); inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec); + if (nilfs_is_metadata_file_inode(inode) && !S_ISREG(inode->i_mode)) + return -EIO; /* this inode is for metadata and corrupted */ if (inode->i_nlink == 0) return -ESTALE; /* this inode is deleted */