linux/net/sched
Eric Dumazet 3db09e762d net/sched: cls_u32: fix netns refcount changes in u32_change()
We are now able to detect extra put_net() at the moment
they happen, instead of much later in correct code paths.

u32_init_knode() / tcf_exts_init() populates the ->exts.net
pointer, but as mentioned in tcf_exts_init(),
the refcount on netns has not been elevated yet.

The refcount is taken only once tcf_exts_get_net()
is called.

So the two u32_destroy_key() calls from u32_change()
are attempting to release an invalid reference on the netns.

syzbot report:

refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 0 PID: 21708 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Modules linked in:
CPU: 0 PID: 21708 Comm: syz-executor.5 Not tainted 5.18.0-rc2-next-20220412-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Code: 1d 14 b6 b2 09 31 ff 89 de e8 6d e9 89 fd 84 db 75 e0 e8 84 e5 89 fd 48 c7 c7 40 aa 26 8a c6 05 f4 b5 b2 09 01 e8 e5 81 2e 05 <0f> 0b eb c4 e8 68 e5 89 fd 0f b6 1d e3 b5 b2 09 31 ff 89 de e8 38
RSP: 0018:ffffc900051af1b0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000040000 RSI: ffffffff8160a0c8 RDI: fffff52000a35e28
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81604a9e R11: 0000000000000000 R12: 1ffff92000a35e3b
R13: 00000000ffffffef R14: ffff8880211a0194 R15: ffff8880577d0a00
FS:  00007f25d183e700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f19c859c028 CR3: 0000000051009000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __refcount_dec include/linux/refcount.h:344 [inline]
 refcount_dec include/linux/refcount.h:359 [inline]
 ref_tracker_free+0x535/0x6b0 lib/ref_tracker.c:118
 netns_tracker_free include/net/net_namespace.h:327 [inline]
 put_net_track include/net/net_namespace.h:341 [inline]
 tcf_exts_put_net include/net/pkt_cls.h:255 [inline]
 u32_destroy_key.isra.0+0xa7/0x2b0 net/sched/cls_u32.c:394
 u32_change+0xe01/0x3140 net/sched/cls_u32.c:909
 tc_new_tfilter+0x98d/0x2200 net/sched/cls_api.c:2148
 rtnetlink_rcv_msg+0x80d/0xb80 net/core/rtnetlink.c:6016
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2495
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 ____sys_sendmsg+0x6e2/0x800 net/socket.c:2413
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f25d0689049
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f25d183e168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f25d079c030 RCX: 00007f25d0689049
RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000000000005
RBP: 00007f25d06e308d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd0b752e3f R14: 00007f25d183e300 R15: 0000000000022000
 </TASK>

Fixes: 35c55fc156 ("cls_u32: use tcf_exts_get_net() before call_rcu()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-15 14:26:11 -07:00
..
act_api.c flow_offload: improve extack msg for user when adding invalid filter 2022-03-02 22:16:10 -08:00
act_bpf.c bpf: Keep the (rcv) timestamp behavior for the existing tc-bpf@ingress 2022-03-03 14:38:48 +00:00
act_connmark.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_csum.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_ct.c net/sched: act_ct: fix ref leak when switching zones 2022-03-26 17:00:51 -07:00
act_ctinfo.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_gact.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_gate.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_ife.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_ipt.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_meta_mark.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
act_meta_skbprio.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
act_meta_skbtcindex.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
act_mirred.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_mpls.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_nat.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_pedit.c flow_offload: add ops to tc_action_ops for flow action setup 2021-12-19 14:08:48 +00:00
act_police.c net: flow_offload: add tc police action parameters 2022-02-28 11:11:35 +00:00
act_sample.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_simple.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_skbedit.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_skbmod.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_tunnel_key.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_vlan.c net/sched: add vlan push_eth and pop_eth action to the hardware IR 2022-03-16 19:59:36 -07:00
cls_api.c net/sched: fix initialization order when updating chain 0 head 2022-04-08 14:45:43 -07:00
cls_basic.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_bpf.c bpf: Keep the (rcv) timestamp behavior for the existing tc-bpf@ingress 2022-03-03 14:38:48 +00:00
cls_cgroup.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_flow.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_flower.c net/sched: flower: fix parsing of ethertype following VLAN header 2022-04-08 12:07:37 +01:00
cls_fw.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_matchall.c flow_offload: validate flags of filter and actions 2021-12-19 14:08:48 +00:00
cls_route.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_rsvp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cls_rsvp.h net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_rsvp6.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cls_tcindex.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_u32.c net/sched: cls_u32: fix netns refcount changes in u32_change() 2022-04-15 14:26:11 -07:00
em_canid.c net: sched: kerneldoc fixes 2020-07-13 17:20:40 -07:00
em_cmp.c net: sched: fix misspellings using misspell-fixer tool 2020-11-10 17:00:28 -08:00
em_ipset.c sched: consistently handle layer3 header accesses in the presence of VLANs 2020-07-03 14:34:53 -07:00
em_ipt.c sched: consistently handle layer3 header accesses in the presence of VLANs 2020-07-03 14:34:53 -07:00
em_meta.c net: introduce sk_forward_alloc_get() 2021-10-27 18:20:29 -07:00
em_nbyte.c net: sched: Return the correct errno code 2021-02-06 11:15:28 -08:00
em_text.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
em_u32.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ematch.c net: sched: Fix spelling mistakes 2021-05-31 22:44:56 -07:00
Kconfig net: sched: incorrect Kconfig dependencies on Netfilter modules 2020-12-09 15:49:29 -08:00
Makefile net/sched: sch_frag: add generic packet fragment support. 2020-11-27 14:36:02 -08:00
sch_api.c net_sched: add __rcu annotation to netdev->qdisc 2022-02-14 13:36:36 +00:00
sch_atm.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_blackhole.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_cake.c sch_cake: revise Diffserv docs 2022-01-07 08:41:29 -08:00
sch_cbq.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_cbs.c net: don't include ethtool.h from netdevice.h 2020-11-23 17:27:04 -08:00
sch_choke.c net: sched: validate stab values 2021-03-10 15:47:52 -08:00
sch_codel.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_drr.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_dsmark.c net/sched: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +01:00
sch_etf.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_ets.c net/sched: sch_ets: don't remove idle classes from the round-robin list 2021-12-13 12:30:23 +00:00
sch_fifo.c net_sched: fix NULL deref in fifo_set_limit() 2021-10-01 14:59:10 -07:00
sch_fq_codel.c fq_codel: generalise ce_threshold marking for subset of traffic 2021-10-20 15:24:36 -07:00
sch_fq_pie.c net/sched: fq_pie: prevent dismantle issue 2021-12-09 08:01:00 -08:00
sch_fq.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_frag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-12-31 14:35:40 +00:00
sch_generic.c net_sched: add __rcu annotation to netdev->qdisc 2022-02-14 13:36:36 +00:00
sch_gred.c net: sched: gred: dynamically allocate tc_gred_qopt_offload 2021-10-27 12:06:52 -07:00
sch_hfsc.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_hhf.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_htb.c sch_htb: Fail on unsupported parameters when offload is requested 2022-01-25 20:00:02 -08:00
sch_ingress.c net: sched: Pass ingress block to tcf_classify_ingress 2020-02-19 17:49:48 -08:00
sch_mq.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_mqprio.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_multiq.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_netem.c net: sched: sch_netem: Refactor code in 4-state loss generator 2021-11-15 13:23:23 +00:00
sch_pie.c net: sched: fix misspellings using misspell-fixer tool 2020-11-10 17:00:28 -08:00
sch_plug.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_prio.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_qfq.c sch_qfq: prevent shift-out-of-bounds in qfq_init_qdisc 2022-01-04 12:36:51 +00:00
sch_red.c net: sched: validate stab values 2021-03-10 15:47:52 -08:00
sch_sfb.c net/sched: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +01:00
sch_sfq.c net/sched: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +01:00
sch_skbprio.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_taprio.c net/sched: taprio: Check if socket flags are valid 2022-04-11 10:51:00 +01:00
sch_tbf.c net: sch_tbf: Add a graft command 2021-10-19 12:24:51 +01:00
sch_teql.c net: sched: sch_teql: fix null-pointer dereference 2021-04-08 14:14:42 -07:00