+ nilfs2-fix-null-pointer-dereference-at-nilfs_bmap_lookup_at_level.patch added to mm-hotfixes-unstable branch

+ nilfs2-fix-null-pointer-dereference-at-nilfs_bmap_lookup_at_level.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: nilfs2: fix NULL pointer dereference at nilfs_bmap_lookup_at_level()
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     nilfs2-fix-null-pointer-dereference-at-nilfs_bmap_lookup_at_level.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/nilfs2-fix-null-pointer-dereference-at-nilfs_bmap_lookup_at_level.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Subject: nilfs2: fix NULL pointer dereference at nilfs_bmap_lookup_at_level()
Date: Sun, 2 Oct 2022 12:08:04 +0900

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>
---

 fs/nilfs2/inode.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/fs/nilfs2/inode.c~nilfs2-fix-null-pointer-dereference-at-nilfs_bmap_lookup_at_level
+++ a/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 */
 
_

Patches currently in -mm which might be from konishi.ryusuke@gmail.com are

nilfs2-fix-use-after-free-bug-of-struct-nilfs_root.patch
nilfs2-fix-null-pointer-dereference-at-nilfs_bmap_lookup_at_level.patch
nilfs2-replace-warn_ons-by-nilfs_error-for-checkpoint-acquisition-failure.patch