From 951ae7dd395dd1407cfc6d7f2f59163850ec0362 Mon Sep 17 00:00:00 2001
From: Yannick Cote <ycote@redhat.com>
Date: Tue, 14 Mar 2023 21:40:48 -0400
Subject: [KPATCH CVE-2022-4744] kpatch fixes for CVE-2022-4744
Kernels:
5.14.0-162.6.1.el9_1
5.14.0-162.12.1.el9_1
5.14.0-162.18.1.el9_1
Kpatch-MR: https://gitlab.com/redhat/prdsc/rhel/src/kpatch/rhel-9/-/merge_requests/28
Approved-by: Joe Lawrence (@joe.lawrence)
Changes since last build:
[x86_64]:
control.o: changed function: snd_ctl_elem_read
control.o: changed function: snd_ctl_ioctl
dev.o: changed function: register_netdevice
tun.o: changed function: tun_free_netdev
tun.o: changed function: tun_set_iff.constprop.0
tun.o: new function: kpp_cve_2022_4744_tun_net_init
[ppc64le]:
dev.o: changed function: register_netdevice
tun.o: changed function: tun_free_netdev
tun.o: changed function: tun_set_iff.constprop.0
tun.o: new function: kpp_cve_2022_4744_tun_net_init
---------------------------
Modifications:
- add shadow variables for tun->ifr, tun->file, ndo_init
- call init from register_netdevice() when shadow variables are detected
- renamed new tun_net_init() -> kpp_cve_2022_4744_tun_net_init()
- code to allocate, maintain and remove shadow variables
commit 8ab79b18abf2f3a2cf33903794ff0de7cec105fc
Author: Jon Maloy <jmaloy@redhat.com>
Date: Wed Mar 8 11:35:45 2023 -0500
tun: avoid double free in tun_free_netdev
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2156372
Upstream: Merged
CVE: CVE-2022-4744
commit 158b515f703e75e7d68289bf4d98c664e1d632df
Author: George Kennedy <george.kennedy@oracle.com>
Date: Thu Dec 16 13:25:32 2021 -0500
tun: avoid double free in tun_free_netdev
Avoid double free in tun_free_netdev() by moving the
dev->tstats and tun->security allocs to a new ndo_init routine
(tun_net_init()) that will be called by register_netdevice().
ndo_init is paired with the desctructor (tun_free_netdev()),
so if there's an error in register_netdevice() the destructor
will handle the frees.
BUG: KASAN: double-free or invalid-free in selinux_tun_dev_free_security+0x1a/0x20 security/selinux/hooks.c:5605
CPU: 0 PID: 25750 Comm: syz-executor416 Not tainted 5.16.0-rc2-syzk #1
Hardware name: Red Hat KVM, BIOS
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x89/0xb5 lib/dump_stack.c:106
print_address_description.constprop.9+0x28/0x160 mm/kasan/report.c:247
kasan_report_invalid_free+0x55/0x80 mm/kasan/report.c:372
____kasan_slab_free mm/kasan/common.c:346 [inline]
__kasan_slab_free+0x107/0x120 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:1723 [inline]
slab_free_freelist_hook mm/slub.c:1749 [inline]
slab_free mm/slub.c:3513 [inline]
kfree+0xac/0x2d0 mm/slub.c:4561
selinux_tun_dev_free_security+0x1a/0x20 security/selinux/hooks.c:5605
security_tun_dev_free_security+0x4f/0x90 security/security.c:2342
tun_free_netdev+0xe6/0x150 drivers/net/tun.c:2215
netdev_run_todo+0x4df/0x840 net/core/dev.c:10627
rtnl_unlock+0x13/0x20 net/core/rtnetlink.c:112
__tun_chr_ioctl+0x80c/0x2870 drivers/net/tun.c:3302
tun_chr_ioctl+0x2f/0x40 drivers/net/tun.c:3311
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x19d/0x220 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3a/0x80 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: George Kennedy <george.kennedy@oracle.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/1639679132-19884-1-git-send-email-george.kennedy@oracle.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Yannick Cote <ycote@redhat.com>
---
drivers/net/tun.c | 135 ++++++++++++++++++++++++++++------------------
net/core/dev.c | 31 ++++++++++-
2 files changed, 112 insertions(+), 54 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index a3aec566fb4b..2a2fee5e3c10 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -216,6 +216,9 @@ struct veth {
__be16 h_vlan_TCI;
};
+static void tun_flow_init(struct tun_struct *tun);
+static void tun_flow_uninit(struct tun_struct *tun);
+
static int tun_napi_receive(struct napi_struct *napi, int budget)
{
struct tun_file *tfile = container_of(napi, struct tun_file, napi);
@@ -953,6 +956,67 @@ static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
static const struct ethtool_ops tun_ethtool_ops;
+/* CVE-2022-4744 - kpatch gathered definitions */
+#ifndef __GENKSYMS__
+/* Note: avoid symvers churn for tun_get_tx_ring and tun_get_socket */
+# include <linux/livepatch.h>
+# define KLP_CVE_2022_4744 0x2022474400000001
+struct klp_cve_2022_4774_t {
+ struct ifreq tun_ifr;
+ struct file tun_file;
+ int (*ndo_init)(struct net_device *netdev);
+};
+#endif
+int kpp_cve_2022_4744_tun_net_init(struct net_device *dev)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+ int err;
+ struct klp_cve_2022_4774_t *klp_sv;
+
+ klp_sv = klp_shadow_get(tun, KLP_CVE_2022_4744);
+ if (!klp_sv)
+ return -EINVAL;
+
+ dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
+ if (!dev->tstats)
+ return -ENOMEM;
+
+ spin_lock_init(&tun->lock);
+
+ err = security_tun_dev_alloc_security(&tun->security);
+ if (err < 0) {
+ free_percpu(dev->tstats);
+ return err;
+ }
+
+ tun_flow_init(tun);
+
+ dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
+ TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
+ NETIF_F_HW_VLAN_STAG_TX;
+ dev->features = dev->hw_features | NETIF_F_LLTX;
+ dev->vlan_features = dev->features &
+ ~(NETIF_F_HW_VLAN_CTAG_TX |
+ NETIF_F_HW_VLAN_STAG_TX);
+ klp_sv = klp_shadow_get(tun, KLP_CVE_2022_4744);
+ if (klp_sv) {
+ tun->flags = (tun->flags & ~TUN_FEATURES) |
+ (klp_sv->tun_ifr.ifr_flags & TUN_FEATURES);
+
+ INIT_LIST_HEAD(&tun->disabled);
+ err = tun_attach(tun, &klp_sv->tun_file, false,
+ klp_sv->tun_ifr.ifr_flags & IFF_NAPI,
+ klp_sv->tun_ifr.ifr_flags & IFF_NAPI_FRAGS, false);
+ }
+ if (err < 0) {
+ tun_flow_uninit(tun);
+ security_tun_dev_free_security(tun->security);
+ free_percpu(dev->tstats);
+ return err;
+ }
+ return 0;
+}
+
/* Net device detach from fd. */
static void tun_net_uninit(struct net_device *dev)
{
@@ -2206,15 +2270,11 @@ static void tun_free_netdev(struct net_device *dev)
BUG_ON(!(list_empty(&tun->disabled)));
free_percpu(dev->tstats);
- /* We clear tstats so that tun_set_iff() can tell if
- * tun_free_netdev() has been called from register_netdevice().
- */
- dev->tstats = NULL;
-
tun_flow_uninit(tun);
security_tun_dev_free_security(tun->security);
__tun_set_ebpf(tun, &tun->steering_prog, NULL);
__tun_set_ebpf(tun, &tun->filter_prog, NULL);
+ klp_shadow_free(tun, KLP_CVE_2022_4744, NULL);
}
static void tun_setup(struct net_device *dev)
@@ -2716,41 +2776,30 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
tun->rx_batched = 0;
RCU_INIT_POINTER(tun->steering_prog, NULL);
- dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
- if (!dev->tstats) {
- err = -ENOMEM;
- goto err_free_dev;
- }
+/* kpatch */
+{
+ struct klp_cve_2022_4774_t *klp_sv;
- spin_lock_init(&tun->lock);
+ klp_sv = klp_shadow_alloc(tun, KLP_CVE_2022_4744,
+ sizeof(*klp_sv), GFP_KERNEL, NULL, NULL);
+ if (!klp_sv) {
+ free_netdev(dev);
+ return -ENOMEM;
+ }
- err = security_tun_dev_alloc_security(&tun->security);
- if (err < 0)
- goto err_free_stat;
+ memcpy(&klp_sv->tun_ifr, ifr, sizeof(*ifr));
+ memcpy(&klp_sv->tun_file, file, sizeof(*file));
+ klp_sv->ndo_init = kpp_cve_2022_4744_tun_net_init;
+}
tun_net_init(dev);
- tun_flow_init(tun);
-
- dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
- TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
- NETIF_F_HW_VLAN_STAG_TX;
- dev->features = dev->hw_features | NETIF_F_LLTX;
- dev->vlan_features = dev->features &
- ~(NETIF_F_HW_VLAN_CTAG_TX |
- NETIF_F_HW_VLAN_STAG_TX);
-
- tun->flags = (tun->flags & ~TUN_FEATURES) |
- (ifr->ifr_flags & TUN_FEATURES);
-
- INIT_LIST_HEAD(&tun->disabled);
- err = tun_attach(tun, file, false, ifr->ifr_flags & IFF_NAPI,
- ifr->ifr_flags & IFF_NAPI_FRAGS, false);
- if (err < 0)
- goto err_free_flow;
err = register_netdevice(tun->dev);
- if (err < 0)
- goto err_detach;
+ if (err < 0) {
+ klp_shadow_free(tun, KLP_CVE_2022_4744, NULL);
+ free_netdev(dev);
+ return err;
+ }
/* free_netdev() won't check refcnt, to avoid race
* with dev_put() we need publish tun after registration.
*/
@@ -2767,24 +2816,6 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
strcpy(ifr->ifr_name, tun->dev->name);
return 0;
-
-err_detach:
- tun_detach_all(dev);
- /* We are here because register_netdevice() has failed.
- * If register_netdevice() already called tun_free_netdev()
- * while dealing with the error, dev->stats has been cleared.
- */
- if (!dev->tstats)
- goto err_free_dev;
-
-err_free_flow:
- tun_flow_uninit(tun);
- security_tun_dev_free_security(tun->security);
-err_free_stat:
- free_percpu(dev->tstats);
-err_free_dev:
- free_netdev(dev);
- return err;
}
static void tun_get_iff(struct tun_struct *tun, struct ifreq *ifr)
diff --git a/net/core/dev.c b/net/core/dev.c
index 89ff6b1e7735..d5f07da178dc 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9544,6 +9544,15 @@ EXPORT_SYMBOL(netif_tx_stop_all_queues);
* will not get the same name.
*/
+/* CVE-2022-4744 - kpatch gathered definitions */
+#include <linux/livepatch.h>
+#define KLP_CVE_2022_4744 0x2022474400000001
+struct klp_cve_2022_4774_t {
+ struct ifreq tun_ifr;
+ struct file tun_file;
+ int (*ndo_init)(struct net_device *netdev);
+};
+
int register_netdevice(struct net_device *dev)
{
int ret;
@@ -9576,15 +9585,33 @@ int register_netdevice(struct net_device *dev)
if (!dev->name_node)
goto out;
+/* kpatch */
+{
/* Init, if this function is available */
- if (dev->netdev_ops->ndo_init) {
- ret = dev->netdev_ops->ndo_init(dev);
+ struct klp_cve_2022_4774_t *klp_sv;
+ int (*ndo_init)(struct net_device *netdev) = NULL;
+
+ /* Does device has shadow variable ndo_init? */
+ if (netdev_priv(dev)) {
+ klp_sv = klp_shadow_get(netdev_priv(dev), KLP_CVE_2022_4744);
+ if (klp_sv && klp_sv->ndo_init)
+ ndo_init = klp_sv->ndo_init;
+ }
+
+ /* How about typical netdev_ops->ndo_init */
+ if (!ndo_init && dev->netdev_ops->ndo_init)
+ ndo_init = dev->netdev_ops->ndo_init;
+
+ /* Run ndo_init callback if found */
+ if (ndo_init) {
+ ret = ndo_init(dev);
if (ret) {
if (ret > 0)
ret = -EIO;
goto err_free_name;
}
}
+}
if (((dev->hw_features | dev->features) &
NETIF_F_HW_VLAN_CTAG_FILTER) &&
--
2.39.2