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 linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <20220617104441.lfhuca6tflg2oxah@quack3.lan> Date: Fri, 17 Jun 2022 12:44:41 +0200 From: Jan Kara <jack@...e.cz> To: Li Lingfeng <lilingfeng3@...wei.com> Cc: linux-ext4@...r.kernel.org, tytso@....edu, adilger.kernel@...ger.ca, linux-kernel@...r.kernel.org, jack@...e.cz, yi.zhang@...wei.com, yukuai3@...wei.com, libaokun2@...wei.com Subject: Re: [PATCH -next] ext4: recover csum seed of tmp_inode after migrating to extents On Fri 17-06-22 14:25:15, Li Lingfeng wrote: > When migrating to extents, the checksum seed of temporary inode > need to be replaced by inode's, otherwise the inode checksums > will be incorrect when swapping the inodes data. > > However, the temporary inode can not match it's checksum to > itself since it has lost it's own checksum seed. > > mkfs.ext4 -F /dev/sdc > mount /dev/sdc /mnt/sdc > xfs_io -fc "pwrite 4k 4k" -c "fsync" /mnt/sdc/testfile > chattr -e /mnt/sdc/testfile > chattr +e /mnt/sdc/testfile > umount /dev/sdc > fsck -fn /dev/sdc > > ======== > ... > Pass 1: Checking inodes, blocks, and sizes > Inode 13 passes checks, but checksum does not match inode. Fix? no > ... > ======== > > The fix is simple, save the checksum seed of temporary inode, and > recover it after migrating to extents. > > Fixes: e81c9302a6c3 ("ext4: set csum seed in tmp inode while migrating to extents") > Signed-off-by: Li Lingfeng <lilingfeng3@...wei.com> Yeah, the migration code and checksums never quite worked together. That's the reason why we'd decided to deprecate this code. But I guess this fix is simple enough and improves things so feel free to add: Reviewed-by: Jan Kara <jack@...e.cz> Honza > --- > fs/ext4/migrate.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c > index 49912814f3d8..04320715d61f 100644 > --- a/fs/ext4/migrate.c > +++ b/fs/ext4/migrate.c > @@ -417,7 +417,7 @@ int ext4_ext_migrate(struct inode *inode) > struct inode *tmp_inode = NULL; > struct migrate_struct lb; > unsigned long max_entries; > - __u32 goal; > + __u32 goal, tmp_csum_seed; > uid_t owner[2]; > > /* > @@ -465,6 +465,7 @@ int ext4_ext_migrate(struct inode *inode) > * the migration. > */ > ei = EXT4_I(inode); > + tmp_csum_seed = EXT4_I(tmp_inode)->i_csum_seed; > EXT4_I(tmp_inode)->i_csum_seed = ei->i_csum_seed; > i_size_write(tmp_inode, i_size_read(inode)); > /* > @@ -575,6 +576,7 @@ int ext4_ext_migrate(struct inode *inode) > * the inode is not visible to user space. > */ > tmp_inode->i_blocks = 0; > + EXT4_I(tmp_inode)->i_csum_seed = tmp_csum_seed; > > /* Reset the extent details */ > ext4_ext_tree_init(handle, tmp_inode); > -- > 2.31.1 > -- Jan Kara <jack@...e.com> SUSE Labs, CR
Powered by blists - more mailing lists