USB: pid_ns: ensure pid is not freed during kill_pid_info_as_uid

Alan Stern points out that after spin_unlock(&ps->lock) there is no
guarantee that ps->pid won't be freed.  Since kill_pid_info_as_uid() is
called after the spin_unlock(), the pid passed to it must be pinned.

Reported-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Serge Hallyn 2011-09-26 10:18:29 -05:00 committed by Greg Kroah-Hartman
parent 5c12e7856d
commit aec01c5895

View File

@ -407,7 +407,7 @@ static void async_completed(struct urb *urb)
sinfo.si_errno = as->status;
sinfo.si_code = SI_ASYNCIO;
sinfo.si_addr = as->userurb;
pid = as->pid;
pid = get_pid(as->pid);
uid = as->uid;
euid = as->euid;
secid = as->secid;
@ -422,9 +422,11 @@ static void async_completed(struct urb *urb)
cancel_bulk_urbs(ps, as->bulk_addr);
spin_unlock(&ps->lock);
if (signr)
if (signr) {
kill_pid_info_as_uid(sinfo.si_signo, &sinfo, pid, uid,
euid, secid);
put_pid(pid);
}
wake_up(&ps->wait);
}