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...

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 */

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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