Re: [PATCH 4.19 5.4 5.10 5.15 6.1 6.6] nilfs2: fix incorrect inode allocation from reserved inodes

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Jul 09, 2024 at 02:33:18PM +0900, Ryusuke Konishi wrote:
> commit 93aef9eda1cea9e84ab2453fcceb8addad0e46f1 upstream.
> 
> If the bitmap block that manages the inode allocation status is corrupted,
> nilfs_ifile_create_inode() may allocate a new inode from the reserved
> inode area where it should not be allocated.
> 
> Previous fix commit d325dc6eb763 ("nilfs2: fix use-after-free bug of
> struct nilfs_root"), fixed the problem that reserved inodes with inode
> numbers less than NILFS_USER_INO (=11) were incorrectly reallocated due to
> bitmap corruption, but since the start number of non-reserved inodes is
> read from the super block and may change, in which case inode allocation
> may occur from the extended reserved inode area.
> 
> If that happens, access to that inode will cause an IO error, causing the
> file system to degrade to an error state.
> 
> Fix this potential issue by adding a wraparound option to the common
> metadata object allocation routine and by modifying
> nilfs_ifile_create_inode() to disable the option so that it only allocates
> inodes with inode numbers greater than or equal to the inode number read
> in "nilfs->ns_first_ino", regardless of the bitmap status of reserved
> inodes.
> 
> Link: https://lkml.kernel.org/r/20240623051135.4180-4-konishi.ryusuke@gmail.com
> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
> Cc: Hillf Danton <hdanton@sina.com>
> Cc: Jan Kara <jack@suse.cz>
> Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
> Please apply this patch to the stable trees indicated by the subject
> prefix instead of the patch that failed.
> 
> This patch is tailored to avoid conflicts with a series involving
> extensive conversions and can be applied from v4.8 to v6.8.
> 
> Also, all the builds and tests I did on each stable tree passed.

Now queued up, thanks.

greg k-h