Re: [PATCH 20/25] sysfs: Rename Support multiple superblocks

From: Tejun Heo
Date: Wed Aug 08 2007 - 12:42:23 EST


Eric W. Biederman wrote:
>> /* Find the first parent which has valid dentry.
>> */
>> dentry = NULL;
>> cur = sd;
>> while (!(dentry = __sysfs_get_dentry(sb, cur))) {
>> if (cur->s_flags & SYSFS_FLAG_REMOVED) {
>> dentry = ERR_PTR(-ENOENT);
>> break;
>> }
>> cur = cur->s_parent;
>> }
>
> Here we depend on the fact that sysfs_root is pointed to
> by sb->s_root so we know it will always have a dentry.

Hmmm... dentry could be ERR_PTR(-ENOENT) here if the REMOVED flag test
succeeded, right?

>> /* from the found dentry, look up depth times */
>> while (dentry->d_fsdata != sd) {

And then dereferenced. The REMOVED test should never succeed there, so
we're probably in the clear but still the code looks a bit scary.

--
tejun
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/