| Message ID | 20231123071314.3332069-1-shaozhengchao@huawei.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | e2b706c691905fe78468c361aaabc719d0a496f1 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,v3] ipv4: igmp: fix refcnt uaf issue when receiving igmp query packet | expand |
On Thu, Nov 23, 2023 at 8:01 AM Zhengchao Shao <shaozhengchao@huawei.com> wrote: > > When I perform the following test operations: > 1.ip link add br0 type bridge > 2.brctl addif br0 eth0 > 3.ip addr add 239.0.0.1/32 dev eth0 > 4.ip addr add 239.0.0.1/32 dev br0 > 5.ip addr add 224.0.0.1/32 dev br0 > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> Reviewed-by: Eric Dumazet <edumazet@google.com>
On Thu, Nov 23, 2023 at 03:13:14PM +0800, Zhengchao Shao wrote: > When I perform the following test operations: > 1.ip link add br0 type bridge > 2.brctl addif br0 eth0 > 3.ip addr add 239.0.0.1/32 dev eth0 > 4.ip addr add 239.0.0.1/32 dev br0 > 5.ip addr add 224.0.0.1/32 dev br0 > 6.while ((1)) > do > ifconfig br0 up > ifconfig br0 down > done > 7.send IGMPv2 query packets to port eth0 continuously. For example, > ./mausezahn ethX -c 0 "01 00 5e 00 00 01 00 72 19 88 aa 02 08 00 45 00 00 > 1c 00 01 00 00 01 02 0e 7f c0 a8 0a b7 e0 00 00 01 11 64 ee 9b 00 00 00 00" > > The preceding tests may trigger the refcnt uaf issue of the mc list. The > stack is as follows: > refcount_t: addition on 0; use-after-free. > WARNING: CPU: 21 PID: 144 at lib/refcount.c:25 refcount_warn_saturate (lib/refcount.c:25) > CPU: 21 PID: 144 Comm: ksoftirqd/21 Kdump: loaded Not tainted 6.7.0-rc1-next-20231117-dirty #80 > Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 > RIP: 0010:refcount_warn_saturate (lib/refcount.c:25) > RSP: 0018:ffffb68f00657910 EFLAGS: 00010286 > RAX: 0000000000000000 RBX: ffff8a00c3bf96c0 RCX: ffff8a07b6160908 > RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff8a07b6160900 > RBP: ffff8a00cba36862 R08: 0000000000000000 R09: 00000000ffff7fff > R10: ffffb68f006577c0 R11: ffffffffb0fdcdc8 R12: ffff8a00c3bf9680 > R13: ffff8a00c3bf96f0 R14: 0000000000000000 R15: ffff8a00d8766e00 > FS: 0000000000000000(0000) GS:ffff8a07b6140000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000055f10b520b28 CR3: 000000039741a000 CR4: 00000000000006f0 > Call Trace: > <TASK> > igmp_heard_query (net/ipv4/igmp.c:1068) > igmp_rcv (net/ipv4/igmp.c:1132) > ip_protocol_deliver_rcu (net/ipv4/ip_input.c:205) > ip_local_deliver_finish (net/ipv4/ip_input.c:234) > __netif_receive_skb_one_core (net/core/dev.c:5529) > netif_receive_skb_internal (net/core/dev.c:5729) > netif_receive_skb (net/core/dev.c:5788) > br_handle_frame_finish (net/bridge/br_input.c:216) > nf_hook_bridge_pre (net/bridge/br_input.c:294) > __netif_receive_skb_core (net/core/dev.c:5423) > __netif_receive_skb_list_core (net/core/dev.c:5606) > __netif_receive_skb_list (net/core/dev.c:5674) > netif_receive_skb_list_internal (net/core/dev.c:5764) > napi_gro_receive (net/core/gro.c:609) > e1000_clean_rx_irq (drivers/net/ethernet/intel/e1000/e1000_main.c:4467) > e1000_clean (drivers/net/ethernet/intel/e1000/e1000_main.c:3805) > __napi_poll (net/core/dev.c:6533) > net_rx_action (net/core/dev.c:6735) > __do_softirq (kernel/softirq.c:554) > run_ksoftirqd (kernel/softirq.c:913) > smpboot_thread_fn (kernel/smpboot.c:164) > kthread (kernel/kthread.c:388) > ret_from_fork (arch/x86/kernel/process.c:153) > ret_from_fork_asm (arch/x86/entry/entry_64.S:250) > </TASK> > > The root causes are as follows: > Thread A Thread B > ... netif_receive_skb > br_dev_stop ... > br_multicast_leave_snoopers ... > __ip_mc_dec_group ... > __igmp_group_dropped igmp_rcv > igmp_stop_timer igmp_heard_query //ref = 1 > ip_ma_put igmp_mod_timer > refcount_dec_and_test igmp_start_timer //ref = 0 > ... refcount_inc //ref increases from 0 > When the device receives an IGMPv2 Query message, it starts the timer > immediately, regardless of whether the device is running. If the device is > down and has left the multicast group, it will cause the mc list refcount > uaf issue. > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> > --- > v3: I add some debug info in net/ipv4/igmp.c, the code is as follows. > Also I remove strace information started with "?" > 1063 if (changed) { > 1064 mdelay(50); > 1065 printk("%s: indev:%s, im->multiaddr=0x%x, im name:%s\n", > 1066 __func__, in_dev->dev ? in_dev->dev->name : "NULL", im->multiaddr, > 1067 im->interface ? im->interface->dev->name : "NULL"); > 1068 igmp_mod_timer(im, max_delay); > 1069 } > v2: use cmd "cat messages |/root/linux-next/scripts/decode_stacktrace.sh > /root/linux-next/vmlinux" to get precise stack traces and check whether > the im is destroyed before timer is started. > --- > net/ipv4/igmp.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c > index 76c3ea75b8dd..efeeca2b1328 100644 > --- a/net/ipv4/igmp.c > +++ b/net/ipv4/igmp.c > @@ -216,8 +216,10 @@ static void igmp_start_timer(struct ip_mc_list *im, int max_delay) > int tv = get_random_u32_below(max_delay); > > im->tm_running = 1; > - if (!mod_timer(&im->timer, jiffies+tv+2)) > - refcount_inc(&im->refcnt); > + if (refcount_inc_not_zero(&im->refcnt)) { > + if (mod_timer(&im->timer, jiffies + tv + 2)) > + ip_ma_put(im); > + } > } > > static void igmp_gq_start_timer(struct in_device *in_dev) > -- > 2.34.1 > Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Hello: This patch was applied to netdev/net.git (main) by David S. Miller <davem@davemloft.net>: On Thu, 23 Nov 2023 15:13:14 +0800 you wrote: > When I perform the following test operations: > 1.ip link add br0 type bridge > 2.brctl addif br0 eth0 > 3.ip addr add 239.0.0.1/32 dev eth0 > 4.ip addr add 239.0.0.1/32 dev br0 > 5.ip addr add 224.0.0.1/32 dev br0 > 6.while ((1)) > do > ifconfig br0 up > ifconfig br0 down > done > 7.send IGMPv2 query packets to port eth0 continuously. For example, > ./mausezahn ethX -c 0 "01 00 5e 00 00 01 00 72 19 88 aa 02 08 00 45 00 00 > 1c 00 01 00 00 01 02 0e 7f c0 a8 0a b7 e0 00 00 01 11 64 ee 9b 00 00 00 00" > > [...] Here is the summary with links: - [net,v3] ipv4: igmp: fix refcnt uaf issue when receiving igmp query packet https://git.kernel.org/netdev/net/c/e2b706c69190 You are awesome, thank you!
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index 76c3ea75b8dd..efeeca2b1328 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -216,8 +216,10 @@ static void igmp_start_timer(struct ip_mc_list *im, int max_delay) int tv = get_random_u32_below(max_delay); im->tm_running = 1; - if (!mod_timer(&im->timer, jiffies+tv+2)) - refcount_inc(&im->refcnt); + if (refcount_inc_not_zero(&im->refcnt)) { + if (mod_timer(&im->timer, jiffies + tv + 2)) + ip_ma_put(im); + } } static void igmp_gq_start_timer(struct in_device *in_dev)
When I perform the following test operations: 1.ip link add br0 type bridge 2.brctl addif br0 eth0 3.ip addr add 239.0.0.1/32 dev eth0 4.ip addr add 239.0.0.1/32 dev br0 5.ip addr add 224.0.0.1/32 dev br0 6.while ((1)) do ifconfig br0 up ifconfig br0 down done 7.send IGMPv2 query packets to port eth0 continuously. For example, ./mausezahn ethX -c 0 "01 00 5e 00 00 01 00 72 19 88 aa 02 08 00 45 00 00 1c 00 01 00 00 01 02 0e 7f c0 a8 0a b7 e0 00 00 01 11 64 ee 9b 00 00 00 00" The preceding tests may trigger the refcnt uaf issue of the mc list. The stack is as follows: refcount_t: addition on 0; use-after-free. WARNING: CPU: 21 PID: 144 at lib/refcount.c:25 refcount_warn_saturate (lib/refcount.c:25) CPU: 21 PID: 144 Comm: ksoftirqd/21 Kdump: loaded Not tainted 6.7.0-rc1-next-20231117-dirty #80 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:refcount_warn_saturate (lib/refcount.c:25) RSP: 0018:ffffb68f00657910 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff8a00c3bf96c0 RCX: ffff8a07b6160908 RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff8a07b6160900 RBP: ffff8a00cba36862 R08: 0000000000000000 R09: 00000000ffff7fff R10: ffffb68f006577c0 R11: ffffffffb0fdcdc8 R12: ffff8a00c3bf9680 R13: ffff8a00c3bf96f0 R14: 0000000000000000 R15: ffff8a00d8766e00 FS: 0000000000000000(0000) GS:ffff8a07b6140000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f10b520b28 CR3: 000000039741a000 CR4: 00000000000006f0 Call Trace: <TASK> igmp_heard_query (net/ipv4/igmp.c:1068) igmp_rcv (net/ipv4/igmp.c:1132) ip_protocol_deliver_rcu (net/ipv4/ip_input.c:205) ip_local_deliver_finish (net/ipv4/ip_input.c:234) __netif_receive_skb_one_core (net/core/dev.c:5529) netif_receive_skb_internal (net/core/dev.c:5729) netif_receive_skb (net/core/dev.c:5788) br_handle_frame_finish (net/bridge/br_input.c:216) nf_hook_bridge_pre (net/bridge/br_input.c:294) __netif_receive_skb_core (net/core/dev.c:5423) __netif_receive_skb_list_core (net/core/dev.c:5606) __netif_receive_skb_list (net/core/dev.c:5674) netif_receive_skb_list_internal (net/core/dev.c:5764) napi_gro_receive (net/core/gro.c:609) e1000_clean_rx_irq (drivers/net/ethernet/intel/e1000/e1000_main.c:4467) e1000_clean (drivers/net/ethernet/intel/e1000/e1000_main.c:3805) __napi_poll (net/core/dev.c:6533) net_rx_action (net/core/dev.c:6735) __do_softirq (kernel/softirq.c:554) run_ksoftirqd (kernel/softirq.c:913) smpboot_thread_fn (kernel/smpboot.c:164) kthread (kernel/kthread.c:388) ret_from_fork (arch/x86/kernel/process.c:153) ret_from_fork_asm (arch/x86/entry/entry_64.S:250) </TASK> The root causes are as follows: Thread A Thread B ... netif_receive_skb br_dev_stop ... br_multicast_leave_snoopers ... __ip_mc_dec_group ... __igmp_group_dropped igmp_rcv igmp_stop_timer igmp_heard_query //ref = 1 ip_ma_put igmp_mod_timer refcount_dec_and_test igmp_start_timer //ref = 0 ... refcount_inc //ref increases from 0 When the device receives an IGMPv2 Query message, it starts the timer immediately, regardless of whether the device is running. If the device is down and has left the multicast group, it will cause the mc list refcount uaf issue. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> --- v3: I add some debug info in net/ipv4/igmp.c, the code is as follows. Also I remove strace information started with "?" 1063 if (changed) { 1064 mdelay(50); 1065 printk("%s: indev:%s, im->multiaddr=0x%x, im name:%s\n", 1066 __func__, in_dev->dev ? in_dev->dev->name : "NULL", im->multiaddr, 1067 im->interface ? im->interface->dev->name : "NULL"); 1068 igmp_mod_timer(im, max_delay); 1069 } v2: use cmd "cat messages |/root/linux-next/scripts/decode_stacktrace.sh /root/linux-next/vmlinux" to get precise stack traces and check whether the im is destroyed before timer is started. --- net/ipv4/igmp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)