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>
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 37518df..eea53eb 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -407,7 +407,7 @@
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 @@
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);
}