From: Li Lingfeng lilingfeng3@huawei.com

hulk inclusion category: bugfix bugzilla: 186944, https://gitee.com/openeuler/kernel/issues/I5DAJY CVE: NA

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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 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@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- 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 75a769634b2b..ed9e7816efbb 100644 --- a/fs/ext4/migrate.c +++ b/fs/ext4/migrate.c @@ -415,7 +415,7 @@ 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];

/* @@ -463,6 +463,7 @@ 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)); /* @@ -573,6 +574,7 @@ 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);