linux/net/sched
Eric Dumazet 560ee196fe net_sched: fix NULL deref in fifo_set_limit()
syzbot reported another NULL deref in fifo_set_limit() [1]

I could repro the issue with :

unshare -n
tc qd add dev lo root handle 1:0 tbf limit 200000 burst 70000 rate 100Mbit
tc qd replace dev lo parent 1:0 pfifo_fast
tc qd change dev lo root handle 1:0 tbf limit 300000 burst 70000 rate 100Mbit

pfifo_fast does not have a change() operation.
Make fifo_set_limit() more robust about this.

[1]
BUG: kernel NULL pointer dereference, address: 0000000000000000
PGD 1cf99067 P4D 1cf99067 PUD 7ca49067 PMD 0
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 14443 Comm: syz-executor959 Not tainted 5.15.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc9000e2f7310 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffffffff8d6ecc00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff888024c27910 RDI: ffff888071e34000
RBP: ffff888071e34000 R08: 0000000000000001 R09: ffffffff8fcfb947
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888024c27910
R13: ffff888071e34018 R14: 0000000000000000 R15: ffff88801ef74800
FS:  00007f321d897700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000000722c3000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 fifo_set_limit net/sched/sch_fifo.c:242 [inline]
 fifo_set_limit+0x198/0x210 net/sched/sch_fifo.c:227
 tbf_change+0x6ec/0x16d0 net/sched/sch_tbf.c:418
 qdisc_change net/sched/sch_api.c:1332 [inline]
 tc_modify_qdisc+0xd9a/0x1a60 net/sched/sch_api.c:1634
 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5572
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:724
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492
 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

Fixes: fb0305ce1b ("net-sched: consolidate default fifo qdisc setup")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Link: https://lore.kernel.org/r/20210930212239.3430364-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-01 14:59:10 -07:00
..
act_api.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_bpf.c bpf: Refactor BPF_PROG_RUN into a function 2021-08-17 00:45:07 +02:00
act_connmark.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_csum.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_ct.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_ctinfo.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_gact.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_gate.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_ife.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_ipt.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-13 06:41:22 -07:00
act_mpls.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_nat.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_pedit.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_police.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_sample.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_simple.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_skbedit.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
act_skbmod.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +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: Fix offloading indirect devices dependency on qdisc order creation 2021-08-19 13:19:30 +01:00
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: protect fl_walk() with rcu 2021-09-30 13:20:31 +01:00
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: 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_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_tcindex.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_u32.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
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 sched: consistently handle layer3 header accesses in the presence of VLANs 2020-07-03 14:34:53 -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: prevent user from passing illegal stab size 2021-09-26 11:09:07 +01:00
sch_atm.c net/sched: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-19 18:09:18 -07:00
sch_cbq.c net: sched: Fix qdisc_rate_table refcount leak when get tcf_block failed 2021-08-30 20:29:03 -07:00
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: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-26 17:57:57 -07:00
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: reject silly quantum parameters 2021-09-04 10:49:46 +01:00
sch_fq_pie.c net/sched: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +01:00
sch_fq.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_frag.c net/sched: sch_frag: fix stack OOB read while fragmenting IPv4 packets 2021-04-29 15:31:53 -07:00
sch_generic.c net: sched: fix lockdep_set_class() typo error for sch->seqlock 2021-08-04 09:59:24 +01:00
sch_gred.c net: sched: Fix spelling mistakes 2021-05-31 22:44:56 -07:00
sch_hfsc.c net/sched: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +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: Fix inconsistency when leaf qdisc creation fails 2021-08-30 16:33:59 -07:00
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: fix dump qlen for sch_mq/sch_mqprio with NOLOCK subqueues 2019-12-03 11:53:55 -08:00
sch_mqprio.c mqprio: Fix out-of-bounds access in mqprio_dump 2019-12-06 11:58:45 -08:00
sch_multiq.c net/sched: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +01:00
sch_netem.c netem: fix zero division in tabledist 2020-10-29 11:45:47 -07:00
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: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +01:00
sch_qfq.c net/sched: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +01:00
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 fix array-index-out-of-bounds in taprio_change 2021-08-30 12:24:40 +01:00
sch_tbf.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_teql.c net: sched: sch_teql: fix null-pointer dereference 2021-04-08 14:14:42 -07:00