lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 3 Aug 2022 09:18:59 +0200 From: Lukas Czerner <lczerner@...hat.com> To: Michael Wu <michael@...winnertech.com> Cc: tytso@....edu, adilger.kernel@...ger.ca, linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org, allwinner-opensource-support@...winnertech.com Subject: Re: [PATCH] ext4: fix error when itable blocks is greater than s_itb_per_group On Tue, Aug 02, 2022 at 10:10:29AM +0800, Michael Wu wrote: > The following error occurs when mounting the ext4 image made by image > making tool: > "ext4_init_inode_table:1301:comm ext4lazyinit:Something is wrong with group > 0: used itable blocks: 491; itable unused count: 0." > > Currently all the inodes in block group0 and ext4 image is divided by > s_inodes_per_group. That leads to a hazard: we can't ensure all > s_inodes_per_group are divisible by s_inodes_per_block. For example, when > the s_inodes_per_group (equals to 7851) is divided by s_inodes_per_block > (which is 16), because 7851 is undivisible by 16, we get the wrong result > 490, while 491 is expected. > > So, we suggest that s_itb_per_group should equal to > DIV_ROUND_UP(s_inodes_per_group, s_inodes_per_block) instead of directly > getting the result from s_inodes_per_group/s_inodes_per_block. Hi Michael, mke2fs is making sure that we completely fill the inote table blocks. This is a corrupted image and so AFAICT ext4 is doing the right thing here. There does not seem to be a problem to fix, unless you can somehow trick mke2fs to make a file system like this. -Lukas > > Signed-off-by: Michael Wu <michael@...winnertech.com> > --- > fs/ext4/super.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 845f2f8aee5f..76cbd638ea10 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -4796,8 +4796,8 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) > sbi->s_inodes_per_group); > goto failed_mount; > } > - sbi->s_itb_per_group = sbi->s_inodes_per_group / > - sbi->s_inodes_per_block; > + sbi->s_itb_per_group = DIV_ROUND_UP(sbi->s_inodes_per_group, > + sbi->s_inodes_per_block); > sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb); > sbi->s_sbh = bh; > sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY; > -- > 2.29.0 >
Powered by blists - more mailing lists