From f60d38cb02d03f39576f9c7ad13652babded2410 Mon Sep 17 00:00:00 2001
From: Edward Adam Davis <eadavis@qq.com>
Date: Sun, 21 Jul 2024 14:23:12 +0800
Subject: [PATCH] pidfs: when time ns disabled add check for ioctl
syzbot call pidfd_ioctl() with cmd "PIDFD_GET_TIME_NAMESPACE" and disabled
CONFIG_TIME_NS, since time_ns is NULL, it will make NULL ponter deref in
open_namespace.
Fixes: 5b08bd408534 ("pidfs: allow retrieval of namespace file descriptors") # mainline only
Reported-and-tested-by: syzbot+34a0ee986f61f15da35d@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=34a0ee986f61f15da35d
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Link: https://lore.kernel.org/r/tencent_7FAE8DB725EE0DD69236DDABDDDE195E4F07@qq.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
fs/pidfs.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/pidfs.c b/fs/pidfs.c
index c9cb14181deff..fe0ddab48f574 100644
--- a/fs/pidfs.c
+++ b/fs/pidfs.c
@@ -168,6 +168,8 @@ static long pidfd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case PIDFD_GET_TIME_NAMESPACE:
get_time_ns(nsp->time_ns);
ns_common = to_ns_common(nsp->time_ns);
+ if (!nsp->time_ns)
+ return -EINVAL;
break;
case PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE:
get_time_ns(nsp->time_ns_for_children);
--
GitLab