Re: [PATCH] f2fs: Add check for deleted inode

[Chao Yu <chao@kernel.org>]

On 2024/11/26 1:56, Leo Stone wrote:
> On Mon, Nov 25, 2024 at 07:16:41PM +0800, Chao Yu wrote:
>>
>> I'm fine w/ this change, but I didn't get it, how did above commit introduce
>> this bug?
> 
> Hello Chao,
> 
> The commit from the bisect didn't exactly introduce this bug, since it
> would still be possible to make a different image that does the exact
> same thing in the older code.
> 
> This commit was blamed in the bisect because it changes the layout of
> struct f2fs_inode:
> 
>> @@ -271,6 +272,10 @@ struct f2fs_inode {
>> 			__le32 i_inode_checksum;/* inode meta checksum */
>> 			__le64 i_crtime;	/* creation time */
>> 			__le32 i_crtime_nsec;	/* creation time in nano scale */
>> +			__le64 i_compr_blocks;	/* # of compressed blocks */
>> +			__u8 i_compress_algorithm;	/* compress algorithm */
>> +			__u8 i_log_cluster_size;	/* log of cluster size */
>> +			__le16 i_padding;		/* padding */
>> 			__le32 i_extra_end[0];	/* for attribute size calculation */
>> 		} __packed;
>> 		__le32 i_addr[DEF_ADDRS_PER_INODE];	/* Pointers to data blocks */
> 
> This changes F2FS_TOTAL_EXTRA_ATTR_SIZE, which allows the syzbot
> reproducer's inode to pass the sanity check for corrupted i_extra_size.
> Before this change, the inode gets rejected as corrupt:
> 
>> [   62.794566][ T9662] F2FS-fs (loop0): sanity_check_inode: inode (ino=7) has corrupted i_extra_isize: 36, max: 24

Leo,

Ah, right, thanks for the explanation, anyway, can you please correct this
"Fixes line"?

Thanks,

> 
> Thanks,
> Leo