linux/net/core
Yue Haibing 1b631bffcb netns: Make get_net_ns() handle zero refcount net
[ Upstream commit ff960f9d3e ]

Syzkaller hit a warning:
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 3 PID: 7890 at lib/refcount.c:25 refcount_warn_saturate+0xdf/0x1d0
Modules linked in:
CPU: 3 PID: 7890 Comm: tun Not tainted 6.10.0-rc3-00100-gcaa4f9578aba-dirty #310
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:refcount_warn_saturate+0xdf/0x1d0
Code: 41 49 04 31 ff 89 de e8 9f 1e cd fe 84 db 75 9c e8 76 26 cd fe c6 05 b6 41 49 04 01 90 48 c7 c7 b8 8e 25 86 e8 d2 05 b5 fe 90 <0f> 0b 90 90 e9 79 ff ff ff e8 53 26 cd fe 0f b6 1
RSP: 0018:ffff8881067b7da0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff811c72ac
RDX: ffff8881026a2140 RSI: ffffffff811c72b5 RDI: 0000000000000001
RBP: ffff8881067b7db0 R08: 0000000000000000 R09: 205b5d3730353139
R10: 0000000000000000 R11: 205d303938375420 R12: ffff8881086500c4
R13: ffff8881086500c4 R14: ffff8881086500b0 R15: ffff888108650040
FS:  00007f5b2961a4c0(0000) GS:ffff88823bd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d7ed36fd18 CR3: 00000001482f6000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ? show_regs+0xa3/0xc0
 ? __warn+0xa5/0x1c0
 ? refcount_warn_saturate+0xdf/0x1d0
 ? report_bug+0x1fc/0x2d0
 ? refcount_warn_saturate+0xdf/0x1d0
 ? handle_bug+0xa1/0x110
 ? exc_invalid_op+0x3c/0xb0
 ? asm_exc_invalid_op+0x1f/0x30
 ? __warn_printk+0xcc/0x140
 ? __warn_printk+0xd5/0x140
 ? refcount_warn_saturate+0xdf/0x1d0
 get_net_ns+0xa4/0xc0
 ? __pfx_get_net_ns+0x10/0x10
 open_related_ns+0x5a/0x130
 __tun_chr_ioctl+0x1616/0x2370
 ? __sanitizer_cov_trace_switch+0x58/0xa0
 ? __sanitizer_cov_trace_const_cmp2+0x1c/0x30
 ? __pfx_tun_chr_ioctl+0x10/0x10
 tun_chr_ioctl+0x2f/0x40
 __x64_sys_ioctl+0x11b/0x160
 x64_sys_call+0x1211/0x20d0
 do_syscall_64+0x9e/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5b28f165d7
Code: b3 66 90 48 8b 05 b1 48 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 48 2d 00 8
RSP: 002b:00007ffc2b59c5e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5b28f165d7
RDX: 0000000000000000 RSI: 00000000000054e3 RDI: 0000000000000003
RBP: 00007ffc2b59c650 R08: 00007f5b291ed8c0 R09: 00007f5b2961a4c0
R10: 0000000029690010 R11: 0000000000000246 R12: 0000000000400730
R13: 00007ffc2b59cf40 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Kernel panic - not syncing: kernel: panic_on_warn set ...

This is trigger as below:
          ns0                                    ns1
tun_set_iff() //dev is tun0
   tun->dev = dev
//ip link set tun0 netns ns1
                                       put_net() //ref is 0
__tun_chr_ioctl() //TUNGETDEVNETNS
   net = dev_net(tun->dev);
   open_related_ns(&net->ns, get_net_ns); //ns1
     get_net_ns()
        get_net() //addition on 0

Use maybe_get_net() in get_net_ns in case net's ref is zero to fix this

Fixes: 0c3e0e3bb6 ("tun: Add ioctl() TUNGETDEVNETNS cmd to allow obtaining real net ns of tun device")
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20240614131302.2698509-1-yuehaibing@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2024-06-27 13:46:19 +02:00
..
bpf_sk_storage.c bpf: Add length check for SK_DIAG_BPF_STORAGE_REQ_MAP_FD parsing 2023-08-11 12:08:12 +02:00
datagram.c net: datagram: fix data-races in datagram_poll() 2023-05-24 17:32:32 +01:00
dev.c net: give more chances to rcu in netdev_wait_allrefs_any() 2024-06-12 11:03:14 +02:00
dev.h net: fix removing a namespace with conflicting altnames 2024-01-31 16:17:04 -08:00
dev_addr_lists.c net: extract a few internals from netdevice.h 2022-04-07 20:32:09 -07:00
dev_addr_lists_test.c net: kunit: add a test for dev_addr_lists 2021-11-20 12:25:57 +00:00
dev_ioctl.c net: dev: Convert sa_data to flexible array in struct sockaddr 2024-03-01 13:26:36 +01:00
drop_monitor.c drop_monitor: replace spin_lock by raw_spin_lock 2024-06-27 13:46:15 +02:00
dst.c ipv6: remove max_size check inline with ipv4 2024-01-15 18:54:51 +01:00
dst_cache.c wireguard: device: reset peer src endpoint when netns exits 2021-11-29 19:50:45 -08:00
failover.c net: rename reference+tracking helpers 2022-06-09 21:52:55 -07:00
fib_notifier.c net: fib_notifier: propagate extack down to the notifier block callback 2019-10-04 11:10:56 -07:00
fib_rules.c fib: expand fib_rule_policy 2021-12-16 07:18:35 -08:00
filter.c bpf: Avoid splat in pskb_pull_reason 2024-06-27 13:46:18 +02:00
flow_dissector.c net/core: Fix ETH_P_1588 flow dissector 2023-10-06 14:56:36 +02:00
flow_offload.c flow_offload: Introduce flow_match_l2tpv3 2022-09-20 09:13:38 +02:00
gen_estimator.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
gen_stats.c net: sched: fix misuse of qcpu->backlog in gnet_stats_add_queue_cpu 2022-08-16 19:38:20 -07:00
gro.c gro: fix ownership transfer 2024-04-10 16:28:26 +02:00
gro_cells.c net: drop the weight argument from netif_napi_add 2022-09-28 18:57:14 -07:00
hwbm.c net: hwbm: Make the hwbm_pool lock a mutex 2019-06-09 19:40:10 -07:00
link_watch.c net-sysfs: convert dev->operstate reads to lockless ones 2024-05-17 11:56:13 +02:00
lwt_bpf.c lwt: Fix return values of BPF xmit ops 2023-09-13 09:42:33 +02:00
lwtunnel.c xfrm: lwtunnel: squelch kernel warning in case XFRM encap type is not available 2022-10-12 10:45:51 +02:00
Makefile devlink: move code to a dedicated directory 2023-08-30 16:11:00 +02:00
neighbour.c neighbour: Don't let neigh_forced_gc() disable preemption for long 2024-01-20 11:50:07 +01:00
net-procfs.c net: extract a few internals from netdevice.h 2022-04-07 20:32:09 -07:00
net-sysfs.c net-sysfs: convert dev->operstate reads to lockless ones 2024-05-17 11:56:13 +02:00
net-sysfs.h net-sysfs: add netdev_change_owner() 2020-02-26 20:07:25 -08:00
net-traces.c tcp: add tracepoint for checksum errors 2021-05-14 15:26:03 -07:00
net_namespace.c netns: Make get_net_ns() handle zero refcount net 2024-06-27 13:46:19 +02:00
netclassid_cgroup.c core: Variable type completion 2022-08-31 09:40:34 +01:00
netevent.c net: core: Correct function name netevent_unregister_notifier() in the kerneldoc 2021-03-28 17:56:56 -07:00
netpoll.c netpoll: Fix race condition in netpoll_owner_active 2024-06-27 13:46:15 +02:00
netprio_cgroup.c bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode 2021-09-13 16:35:58 -07:00
of_net.c Revert "of: net: support NVMEM cells with MAC in text format" 2022-01-12 14:14:36 +00:00
page_pool.c net: page_pool: add missing free_percpu when page_pool_init fail 2023-11-20 11:52:16 +01:00
pktgen.c net: pktgen: Fix interface flags printing 2023-10-25 12:03:08 +02:00
ptp_classifier.c ptp: Add generic PTP is_sync() function 2022-03-07 11:31:34 +00:00
request_sock.c tcp: make sure init the accept_queue's spinlocks once 2024-01-31 16:17:03 -08:00
rtnetlink.c net-sysfs: convert dev->operstate reads to lockless ones 2024-05-17 11:56:13 +02:00
scm.c io_uring/unix: drop usage of io_uring socket 2024-03-26 18:20:22 -04:00
secure_seq.c tcp: Fix data-races around sysctl knobs related to SYN option. 2022-07-20 10:14:49 +01:00
selftests.c net: core: constify mac addrs in selftests 2021-10-24 13:59:44 +01:00
skbuff.c net: core: reject skb_copy(_expand) for fraglist GSO skbs 2024-05-17 11:56:01 +02:00
skmsg.c bpf, skmsg: Fix NULL pointer dereference in sk_psock_skb_ingress_enqueue 2024-05-17 11:55:56 +02:00
sock.c net: mark racy access on sk->sk_rcvbuf 2024-05-17 11:56:04 +02:00
sock_destructor.h skb_expand_head() adjust skb->truesize incorrectly 2021-10-22 12:35:51 -07:00
sock_diag.c sock_diag: annotate data-races around sock_diag_handlers[family] 2024-03-26 18:20:31 -04:00
sock_map.c sock_map: avoid race between sock_map_close and sk_psock_put 2024-06-21 14:35:55 +02:00
sock_reuseport.c soreuseport: Fix socket selection for SO_INCOMING_CPU. 2022-12-31 13:32:04 +01:00
stream.c net: Return error from sk_stream_wait_connect() if sk_wait_event() fails 2024-01-01 12:38:56 +00:00
sysctl_net_core.c net: make SK_MEMORY_PCPU_RESERV tunable 2024-05-02 16:29:24 +02:00
timestamping.c net: Introduce a new MII time stamping interface. 2019-12-25 19:51:33 -08:00
tso.c net: tso: add UDP segmentation support 2020-06-18 20:46:23 -07:00
utils.c net: core: Use csum_replace_by_diff() and csum_sub() instead of opencoding 2022-02-21 11:40:44 +00:00
xdp.c xdp: improve page_pool xdp_return performance 2022-09-26 11:28:19 -07:00