[LU-8258] Unsafe userspace address access from proc handler in nodemap code

• Type: Bug
• Resolution: Fixed
• Priority: Critical
• Fix Version/s: Lustre 2.9.0
• Severity: 3
• Assignee: Kit Westneat (Inactive)
• Reporter: Oleg Drokin

Description

Patch http://review.whamcloud.com/18783 added this bit of code:

nodemap_fileset_seq_write(struct file *file,
                                      const char __user *buffer,
                                      size_t count, loff_t *off)
{
        struct seq_file *m = file->private_data;
        int rc = 0;

        if (count > 0)
                rc = nodemap_set_fileset(m->private, buffer);

        if (rc != 0)
                return -EINVAL;

        return count;
}

Now the problem is - buffer is in userspace, so we cannot just pass it like this to nodemap_set_fileset where it would get dereferenced.
We need to properly copy it to kernelspace first.

Comments

[Joseph Gmitter (Inactive)]

Landed to master for 2.9.0

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch http://review.whamcloud.com/21857/
Subject: LU-8258 nodemap: fix userspace address access in proc code
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 288e55b8a38222af843a71a89df90234a72d8e0d

[Gerrit Updater]

Kit Westneat ([e-mail]) uploaded a new patch: http://review.whamcloud.com/21857
Subject: LU-8258 nodemap: fix userspace address access in proc code
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 001098168e33dbd856537725fc2dca1b3135cab7

[Peter Jones]

Kit

Are you able to help with this one?

Peter