linux/net/sched
Eric Dumazet c1a2b52d99 sch_netem: acquire qdisc lock in netem_change()
[ Upstream commit 2174a08db8 ]

syzbot managed to trigger a divide error [1] in netem.

It could happen if q->rate changes while netem_enqueue()
is running, since q->rate is read twice.

It turns out netem_change() always lacked proper synchronization.

[1]
divide error: 0000 [#1] SMP KASAN
CPU: 1 PID: 7867 Comm: syz-executor.1 Not tainted 6.1.30-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
RIP: 0010:div64_u64 include/linux/math64.h:69 [inline]
RIP: 0010:packet_time_ns net/sched/sch_netem.c:357 [inline]
RIP: 0010:netem_enqueue+0x2067/0x36d0 net/sched/sch_netem.c:576
Code: 89 e2 48 69 da 00 ca 9a 3b 42 80 3c 28 00 4c 8b a4 24 88 00 00 00 74 0d 4c 89 e7 e8 c3 4f 3b fd 48 8b 4c 24 18 48 89 d8 31 d2 <49> f7 34 24 49 01 c7 4c 8b 64 24 48 4d 01 f7 4c 89 e3 48 c1 eb 03
RSP: 0018:ffffc9000dccea60 EFLAGS: 00010246
RAX: 000001a442624200 RBX: 000001a442624200 RCX: ffff888108a4f000
RDX: 0000000000000000 RSI: 000000000000070d RDI: 000000000000070d
RBP: ffffc9000dcceb90 R08: ffffffff849c5e26 R09: fffffbfff10e1297
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888108a4f358
R13: dffffc0000000000 R14: 0000001a8cd9a7ec R15: 0000000000000000
FS: 00007fa73fe18700(0000) GS:ffff8881f6b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa73fdf7718 CR3: 000000011d36e000 CR4: 0000000000350ee0
Call Trace:
<TASK>
[<ffffffff84714385>] __dev_xmit_skb net/core/dev.c:3931 [inline]
[<ffffffff84714385>] __dev_queue_xmit+0xcf5/0x3370 net/core/dev.c:4290
[<ffffffff84d22df2>] dev_queue_xmit include/linux/netdevice.h:3030 [inline]
[<ffffffff84d22df2>] neigh_hh_output include/net/neighbour.h:531 [inline]
[<ffffffff84d22df2>] neigh_output include/net/neighbour.h:545 [inline]
[<ffffffff84d22df2>] ip_finish_output2+0xb92/0x10d0 net/ipv4/ip_output.c:235
[<ffffffff84d21e63>] __ip_finish_output+0xc3/0x2b0
[<ffffffff84d10a81>] ip_finish_output+0x31/0x2a0 net/ipv4/ip_output.c:323
[<ffffffff84d10f14>] NF_HOOK_COND include/linux/netfilter.h:298 [inline]
[<ffffffff84d10f14>] ip_output+0x224/0x2a0 net/ipv4/ip_output.c:437
[<ffffffff84d123b5>] dst_output include/net/dst.h:444 [inline]
[<ffffffff84d123b5>] ip_local_out net/ipv4/ip_output.c:127 [inline]
[<ffffffff84d123b5>] __ip_queue_xmit+0x1425/0x2000 net/ipv4/ip_output.c:542
[<ffffffff84d12fdc>] ip_queue_xmit+0x4c/0x70 net/ipv4/ip_output.c:556

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230620184425.1179809-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-28 10:29:50 +02:00
..
act_api.c net/sched: act_api: Notify user space if any actions were flushed before error 2022-07-07 17:53:27 +02:00
act_bpf.c flow_offload: fill flags to action structure 2023-02-22 12:57:10 +01:00
act_connmark.c flow_offload: fill flags to action structure 2023-02-22 12:57:10 +01:00
act_csum.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_ct.c netfilter: conntrack: Fix data-races around ct mark 2022-12-02 17:41:04 +01:00
act_ctinfo.c net/sched: act_ctinfo: use percpu stats 2023-02-22 12:57:10 +01:00
act_gact.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_gate.c flow_offload: fill flags to action structure 2023-02-22 12:57:10 +01:00
act_ife.c flow_offload: fill flags to action structure 2023-02-22 12:57:10 +01:00
act_ipt.c flow_offload: fill flags to action structure 2023-02-22 12:57:10 +01:00
act_meta_mark.c
act_meta_skbprio.c
act_meta_skbtcindex.c
act_mirred.c net/sched: act_mirred: Add carrier check 2023-05-17 11:50:17 +02:00
act_mpls.c net/sched: act_mpls: fix action bind logic 2023-03-11 13:57:30 +01:00
act_nat.c flow_offload: fill flags to action structure 2023-02-22 12:57:10 +01:00
act_pedit.c net/sched: act_pedit: Parse L3 Header for L4 offset 2023-06-21 15:59:16 +02:00
act_police.c net: sched: act_police: fix sparse errors in tcf_police_dump() 2023-06-14 11:13:03 +02:00
act_sample.c net/sched: act_sample: fix action bind logic 2023-03-11 13:57:30 +01:00
act_simple.c flow_offload: fill flags to action structure 2023-02-22 12:57:10 +01:00
act_skbedit.c flow_offload: fill flags to action structure 2023-02-22 12:57:10 +01:00
act_skbmod.c flow_offload: fill flags to action structure 2023-02-22 12:57:10 +01:00
act_tunnel_key.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_vlan.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_api.c net/sched: cls_api: Fix lockup on flushing explicitly created chain 2023-06-21 15:59:18 +02:00
cls_basic.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_bpf.c bpf: Refactor BPF_PROG_RUN into a function 2021-08-17 00:45:07 +02:00
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 possible OOB write in fl_set_geneve_opt() 2023-06-09 10:32:18 +02:00
cls_fw.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_matchall.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_route.c net_sched: cls_route: disallow handle of 0 2022-08-21 15:17:48 +02:00
cls_rsvp6.c
cls_rsvp.c
cls_rsvp.h net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_u32.c net/sched: cls_u32: Fix reference counter leak leading to overflow 2023-06-21 15:59:16 +02:00
em_canid.c
em_cmp.c net: sched: fix misspellings using misspell-fixer tool 2020-11-10 17:00:28 -08:00
em_ipset.c
em_ipt.c
em_meta.c
em_nbyte.c net: sched: Return the correct errno code 2021-02-06 11:15:28 -08:00
em_text.c
em_u32.c
ematch.c net_sched: reject TCF_EM_SIMPLE case for complex ematch module 2022-12-31 13:14:39 +01:00
Kconfig net/sched: Retire tcindex classifier 2023-03-11 13:57:22 +01:00
Makefile net/sched: Retire tcindex classifier 2023-03-11 13:57:22 +01:00
sch_api.c net: sched: fix NULL pointer dereference in mq_attach 2023-06-09 10:32:18 +02:00
sch_atm.c net: sched: atm: dont intepret cls results when asked to drop 2023-01-12 11:59:14 +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 net: sched: cake: fix null pointer access issue when cake_init() fails 2022-10-29 10:12:57 +02:00
sch_cbq.c net: sched: cbq: dont intepret cls results when asked to drop 2023-01-12 11:59:14 +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: delete duplicate cleanup of backlog and qlen 2022-10-29 10:12:57 +02:00
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: delete duplicate cleanup of backlog and qlen 2022-10-29 10:12:57 +02:00
sch_dsmark.c net: sched: delete duplicate cleanup of backlog and qlen 2022-10-29 10:12:57 +02:00
sch_etf.c net: sched: delete duplicate cleanup of backlog and qlen 2022-10-29 10:12:57 +02:00
sch_ets.c net: sched: delete duplicate cleanup of backlog and qlen 2022-10-29 10:12:57 +02:00
sch_fifo.c net_sched: fix NULL deref in fifo_set_limit() 2021-10-01 14:59:10 -07:00
sch_fq_codel.c net: sched: delete duplicate cleanup of backlog and qlen 2022-10-29 10:12:57 +02:00
sch_fq_pie.c net/sched: fq_pie: ensure reasonable TCA_FQ_PIE_QUANTUM values 2023-06-14 11:13:01 +02:00
sch_fq.c net/sched: sch_fq: fix integer overflow of "credit" 2023-05-11 23:00:31 +09:00
sch_frag.c net/sched: Extend qdisc control block with tc control block 2022-01-05 12:42:33 +01:00
sch_generic.c net/sched: fix netdevice reference leaks in attach_default_qdiscs() 2022-09-08 12:28:02 +02:00
sch_gred.c net: sched: Fix spelling mistakes 2021-05-31 22:44:56 -07:00
sch_hfsc.c net: sched: delete duplicate cleanup of backlog and qlen 2022-10-29 10:12:57 +02:00
sch_hhf.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_htb.c net: sched: sch: Fix off by one in htb_activate_prios() 2023-02-22 12:57:11 +01:00
sch_ingress.c net/sched: Reserve TC_H_INGRESS (TC_H_CLSACT) for ingress (clsact) Qdiscs 2023-06-09 10:32:17 +02:00
sch_mq.c net: sched: update default qdisc visibility after Tx queue cnt changes 2021-11-18 19:16:10 +01:00
sch_mqprio.c net: sched: update default qdisc visibility after Tx queue cnt changes 2021-11-18 19:16:10 +01:00
sch_multiq.c net: sched: delete duplicate cleanup of backlog and qlen 2022-10-29 10:12:57 +02:00
sch_netem.c sch_netem: acquire qdisc lock in netem_change() 2023-06-28 10:29:50 +02:00
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: delete duplicate cleanup of backlog and qlen 2022-10-29 10:12:57 +02:00
sch_qfq.c net: sched: sch_qfq: prevent slab-out-of-bounds in qfq_activate_agg 2023-04-26 13:51:47 +02:00
sch_red.c net: sched: Fix use after free in red_enqueue() 2022-11-10 18:15:28 +01:00
sch_sfb.c net: sched: sfb: fix null pointer access issue when sfb_init() fails 2022-10-29 10:12:57 +02:00
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 net: sched: delete duplicate cleanup of backlog and qlen 2022-10-29 10:12:57 +02:00
sch_taprio.c Revert "net/sched: taprio: make qdisc_leaf() see the per-netdev-queue pfifo child qdiscs" 2023-02-25 12:06:46 +01:00
sch_tbf.c net: sched: delete duplicate cleanup of backlog and qlen 2022-10-29 10:12:57 +02:00
sch_teql.c net: sched: delete duplicate cleanup of backlog and qlen 2022-10-29 10:12:57 +02:00