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de6d25924c
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 [#1] PREEMPT SMP NOPTI
CPU: 1 PID: 910 Comm: mausezahn Not tainted 5.16.0-rc1+ #475
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:
|
||
|---|---|---|
| .. | ||
| act_api.c | ||
| act_bpf.c | ||
| act_connmark.c | ||
| act_csum.c | ||
| act_ct.c | ||
| act_ctinfo.c | ||
| act_gact.c | ||
| act_gate.c | ||
| act_ife.c | ||
| act_ipt.c | ||
| act_meta_mark.c | ||
| act_meta_skbprio.c | ||
| act_meta_skbtcindex.c | ||
| act_mirred.c | ||
| act_mpls.c | ||
| act_nat.c | ||
| act_pedit.c | ||
| act_police.c | ||
| act_sample.c | ||
| act_simple.c | ||
| act_skbedit.c | ||
| act_skbmod.c | ||
| 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_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 | ||
| em_nbyte.c | ||
| em_text.c | ||
| em_u32.c | ||
| ematch.c | ||
| Kconfig | ||
| Makefile | ||
| sch_api.c | ||
| sch_atm.c | ||
| sch_blackhole.c | ||
| sch_cake.c | ||
| sch_cbq.c | ||
| sch_cbs.c | ||
| sch_choke.c | ||
| sch_codel.c | ||
| sch_drr.c | ||
| sch_dsmark.c | ||
| sch_etf.c | ||
| sch_ets.c | ||
| sch_fifo.c | ||
| sch_fq_codel.c | ||
| sch_fq_pie.c | ||
| sch_fq.c | ||
| sch_frag.c | ||
| sch_generic.c | ||
| sch_gred.c | ||
| sch_hfsc.c | ||
| sch_hhf.c | ||
| sch_htb.c | ||
| sch_ingress.c | ||
| sch_mq.c | ||
| sch_mqprio.c | ||
| sch_multiq.c | ||
| sch_netem.c | ||
| sch_pie.c | ||
| sch_plug.c | ||
| sch_prio.c | ||
| sch_qfq.c | ||
| sch_red.c | ||
| sch_sfb.c | ||
| sch_sfq.c | ||
| sch_skbprio.c | ||
| sch_taprio.c | ||
| sch_tbf.c | ||
| sch_teql.c | ||