From: Serge Hallyn <serge.hallyn@canonical.com>
Date: Mon, 26 Sep 2011 15:18:29 +0000 (-0500)
Subject: USB: pid_ns: ensure pid is not freed during kill_pid_info_as_uid
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=aec01c5895051849ed842dc5b8794017a7751f28;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

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 37518dfdeb98..eea53ebe6706 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -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);
 }