leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
4cd8371a23
linux/net/sched
History
Davide Caratti de6d25924c net/sched: sch_ets: don't peek at classes beyond 'nbands' 
when the number of DRR classes decreases, the round-robin active list can
contain elements that have already been freed in ets_qdisc_change(). As a
consequence, it's possible to see a NULL dereference crash, caused by the
attempt to call cl->qdisc->ops->peek(cl->qdisc) when cl->qdisc is NULL:

 BUG: kernel NULL pointer dereference, address: 0000000000000018
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [] PREEMPT SMP NOPTI
 CPU: 1 PID: 910 Comm: mausezahn Not tainted 5.16.0-rc1+ 
 Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014
 RIP: 0010:ets_qdisc_dequeue+0x129/0x2c0 [sch_ets]
 Code: c5 01 41 39 ad e4 02 00 00 0f 87 18 ff ff ff 49 8b 85 c0 02 00 00 49 39 c4 0f 84 ba 00 00 00 49 8b ad c0 02 00 00 48 8b 7d 10 <48> 8b 47 18 48 8b 40 38 0f ae e8 ff d0 48 89 c3 48 85 c0 0f 84 9d
 RSP: 0000:ffffbb36c0b5fdd8 EFLAGS: 00010287
 RAX: ffff956678efed30 RBX: 0000000000000000 RCX: 0000000000000000
 RDX: 0000000000000002 RSI: ffffffff9b938dc9 RDI: 0000000000000000
 RBP: ffff956678efed30 R08: e2f3207fe360129c R09: 0000000000000000
 R10: 0000000000000001 R11: 0000000000000001 R12: ffff956678efeac0
 R13: ffff956678efe800 R14: ffff956611545000 R15: ffff95667ac8f100
 FS:  00007f2aa9120740(0000) GS:ffff95667b800000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000018 CR3: 000000011070c000 CR4: 0000000000350ee0
 Call Trace:
  <TASK>
  qdisc_peek_dequeued+0x29/0x70 [sch_ets]
  tbf_dequeue+0x22/0x260 [sch_tbf]
  __qdisc_run+0x7f/0x630
  net_tx_action+0x290/0x4c0
  __do_softirq+0xee/0x4f8
  irq_exit_rcu+0xf4/0x130
  sysvec_apic_timer_interrupt+0x52/0xc0
  asm_sysvec_apic_timer_interrupt+0x12/0x20
 RIP: 0033:0x7f2aa7fc9ad4
 Code: b9 ff ff 48 8b 54 24 18 48 83 c4 08 48 89 ee 48 89 df 5b 5d e9 ed fc ff ff 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa <53> 48 83 ec 10 48 8b 05 10 64 33 00 48 8b 00 48 85 c0 0f 85 84 00
 RSP: 002b:00007ffe5d33fab8 EFLAGS: 00000202
 RAX: 0000000000000002 RBX: 0000561f72c31460 RCX: 0000561f72c31720
 RDX: 0000000000000002 RSI: 0000561f72c31722 RDI: 0000561f72c31720
 RBP: 000000000000002a R08: 00007ffe5d33fa40 R09: 0000000000000014
 R10: 0000000000000000 R11: 0000000000000246 R12: 0000561f7187e380
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000561f72c31460
  </TASK>
 Modules linked in: sch_ets sch_tbf dummy rfkill iTCO_wdt intel_rapl_msr iTCO_vendor_support intel_rapl_common joydev virtio_balloon lpc_ich i2c_i801 i2c_smbus pcspkr ip_tables xfs libcrc32c crct10dif_pclmul crc32_pclmul crc32c_intel ahci libahci ghash_clmulni_intel serio_raw libata virtio_blk virtio_console virtio_net net_failover failover sunrpc dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000018

Ensuring that 'alist' was never zeroed [1] was not sufficient, we need to
remove from the active list those elements that are no more SP nor DRR.

[1] https://lore.kernel.org/netdev/60d274838bf09777f0371253416e8af71360bc08.1633609148.git.dcaratti@redhat.com/

v3: fix race between ets_qdisc_change() and ets_qdisc_dequeue() delisting
    DRR classes beyond 'nbands' in ets_qdisc_change() with the qdisc lock
    acquired, thanks to Cong Wang.

v2: when a NULL qdisc is found in the DRR active list, try to dequeue skb
    from the next list item.

Reported-by: Hangbin Liu <liuhangbin@gmail.com>
Fixes: dcc68b4d80 ("net: sch_ets: Add a new Qdisc")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/r/7a5c496eed2d62241620bdbb83eb03fb9d571c99.1637762721.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-26 11:10:20 -08:00
..
act_api.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
act_bpf.c net: sched: Merge Qdisc::bstats and Qdisc::cpu_bstats data types 2021-10-18 12:54:41 +01:00
act_connmark.c
act_csum.c
act_ct.c net/sched: act_ct: Fix byte count on fragmented packets 2021-10-18 13:31:58 +01:00
act_ctinfo.c
act_gact.c
act_gate.c
act_ife.c net: sched: Merge Qdisc::bstats and Qdisc::cpu_bstats data types 2021-10-18 12:54:41 +01:00
act_ipt.c
act_meta_mark.c
act_meta_skbprio.c
act_meta_skbtcindex.c
act_mirred.c net: sched: act_mirred: drop dst for the direction from egress to ingress 2021-11-16 19:17:38 -08:00
act_mpls.c net: sched: Merge Qdisc::bstats and Qdisc::cpu_bstats data types 2021-10-18 12:54:41 +01:00
act_nat.c
act_pedit.c
act_police.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
act_sample.c net: sched: Merge Qdisc::bstats and Qdisc::cpu_bstats data types 2021-10-18 12:54:41 +01:00
act_simple.c net: sched: Merge Qdisc::bstats and Qdisc::cpu_bstats data types 2021-10-18 12:54:41 +01:00
act_skbedit.c net: sched: Merge Qdisc::bstats and Qdisc::cpu_bstats data types 2021-10-18 12:54:41 +01:00
act_skbmod.c net: sched: Merge Qdisc::bstats and Qdisc::cpu_bstats data types 2021-10-18 12:54:41 +01:00
act_tunnel_key.c
act_vlan.c
cls_api.c
cls_basic.c
cls_bpf.c
cls_cgroup.c
cls_flow.c
cls_flower.c cls_flower: Fix inability to match GRE/IPIP packets 2021-10-29 14:03:22 +01:00
cls_fw.c
cls_matchall.c
cls_route.c
cls_rsvp6.c
cls_rsvp.c
cls_rsvp.h
cls_tcindex.c
cls_u32.c
em_canid.c
em_cmp.c
em_ipset.c
em_ipt.c
em_meta.c net: introduce sk_forward_alloc_get() 2021-10-27 18:20:29 -07:00
em_nbyte.c
em_text.c
em_u32.c
ematch.c
Kconfig
Makefile
sch_api.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_atm.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_blackhole.c
sch_cake.c
sch_cbq.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_cbs.c
sch_choke.c
sch_codel.c
sch_drr.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_dsmark.c
sch_etf.c
sch_ets.c net/sched: sch_ets: don't peek at classes beyond 'nbands' 2021-11-26 11:10:20 -08:00
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
sch_fq.c
sch_frag.c
sch_generic.c net: sch: simplify condtion for selecting mini_Qdisc_pair buffer 2021-10-27 17:09:26 -07:00
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
sch_htb.c sch_htb: Add extack messages for EOPNOTSUPP errors 2021-10-28 14:34:03 +01:00
sch_ingress.c
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: Use struct_size() helper in kvmalloc() 2021-09-30 17:27:03 -07:00
sch_pie.c
sch_plug.c
sch_prio.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_qfq.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_red.c
sch_sfb.c
sch_sfq.c
sch_skbprio.c
sch_taprio.c net/sched: sch_taprio: fix undefined behavior in ktime_mono_to_any 2021-11-09 19:16:23 -08:00
sch_tbf.c net: sch_tbf: Add a graft command 2021-10-19 12:24:51 +01:00
sch_teql.c