Re: [PATCH] JFS: ensure link targets are NULL-terminated

From: Duane Griffin
Date: Thu Dec 11 2008 - 15:35:00 EST


2008/12/11 Dave Kleikamp <shaggy@xxxxxxxxxxxxxxxxxx>:
> Thanks.
>
> I came up with an alternate patch that I like slightly better. This one
> null-terminates the string when the inode is read rather than every time
> the link is followed, and at the proper place (i_size). It's not a big
> deal, since the symlink will be corrupted either way. What do you think
> of this patch?
>
> Signed-off-by: Dave Kleikamp <shaggy@xxxxxxxxxxxxxxxxxx>
>
> diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c
> index 2103397..b00ee9f 100644
> --- a/fs/jfs/inode.c
> +++ b/fs/jfs/inode.c
> @@ -59,8 +59,14 @@ struct inode *jfs_iget(struct super_block *sb, unsigned long ino)
> if (inode->i_size >= IDATASIZE) {
> inode->i_op = &page_symlink_inode_operations;
> inode->i_mapping->a_ops = &jfs_aops;
> - } else
> + } else {
> inode->i_op = &jfs_symlink_inode_operations;
> + /*
> + * The inline data should be null-terminated, but
> + * don't let on-disk corruption crash the kernel
> + */
> + JFS_IP(inode)->i_inline[inode->i_size] = '\0';
> + }
> } else {
> inode->i_op = &jfs_file_inode_operations;
> init_special_inode(inode, inode->i_mode, inode->i_rdev);

Yes, I prefer your version too :)

I'll rework the other patches similarly, where appropriate. Thanks!

Cheers,
Duane.

--
"I never could learn to drink that blood and call it wine" - Bob Dylan
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