netdev - [PATCH] net: fix oops in socket ioctl cmd SIOCGSKNS when NET

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210529060526.422987-1-changbin.du@gmail.com>
Date:   Sat, 29 May 2021 14:05:26 +0800
From:   Changbin Du <changbin.du@...il.com>
To:     "David S. Miller" <davem@...emloft.net>,
        Jakub Kici nski <kuba@...nel.org>
Cc:     netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        Changbin Du <changbin.du@...il.com>, stable@...r.kernel.org
Subject: [PATCH] net: fix oops in socket ioctl cmd SIOCGSKNS when NET_NS is disabled

When NET_NS is not enabled, socket ioctl cmd SIOCGSKNS should do nothing
but acknowledge userspace it is not supported. Otherwise, kernel would
panic wherever nsfs trys to access ns->ops since the proc_ns_operations
is not implemented in this case.

[7.670023] Unable to handle kernel NULL pointer dereference at virtual address 00000010
[7.670268] pgd = 32b54000
[7.670544] [00000010] *pgd=00000000
[7.671861] Internal error: Oops: 5 [#1] SMP ARM
[7.672315] Modules linked in:
[7.672918] CPU: 0 PID: 1 Comm: systemd Not tainted 5.13.0-rc3-00375-g6799d4f2da49 #16
[7.673309] Hardware name: Generic DT based system
[7.673642] PC is at nsfs_evict+0x24/0x30
[7.674486] LR is at clear_inode+0x20/0x9c

Signed-off-by: Changbin Du <changbin.du@...il.com>
Cc: <stable@...r.kernel.org> # v4.9
---
 net/socket.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/socket.c b/net/socket.c
index 27e3e7d53f8e..644b46112d35 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1149,11 +1149,15 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 			mutex_unlock(&vlan_ioctl_mutex);
 			break;
 		case SIOCGSKNS:
+#ifdef CONFIG_NET_NS
 			err = -EPERM;
 			if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 				break;
 
 			err = open_related_ns(&net->ns, get_net_ns);
+#else
+			err = -ENOTSUPP;
+#endif
 			break;
 		case SIOCGSTAMP_OLD:
 		case SIOCGSTAMPNS_OLD:
-- 
2.27.0