138470a9b2
Convert zones_lock spinlock to zones_mutex mutex,
and struct (tcf_ct_flow_table)->ref to a refcount,
so that control path can use regular GFP_KERNEL allocations
from standard process context. This is more robust
in case of memory pressure.
The refcount is needed because tcf_ct_flow_table_put() can
be called from RCU callback, thus in BH context.
The issue was spotted by syzbot, as rhashtable_init()
was called with a spinlock held, which is bad since GFP_KERNEL
allocations can sleep.
Note to developers : Please make sure your patches are tested
with CONFIG_DEBUG_ATOMIC_SLEEP=y
BUG: sleeping function called from invalid context at mm/slab.h:565
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 9582, name: syz-executor610
2 locks held by syz-executor610/9582:
#0: ffffffff8a34eb80 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8a34eb80 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5437
#1: ffffffff8a3961b8 (zones_lock){+...}, at: spin_lock_bh include/linux/spinlock.h:343 [inline]
#1: ffffffff8a3961b8 (zones_lock){+...}, at: tcf_ct_flow_table_get+0xa3/0x1700 net/sched/act_ct.c:67
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 0 PID: 9582 Comm: syz-executor610 Not tainted 5.6.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x188/0x20d lib/dump_stack.c:118
___might_sleep.cold+0x1f4/0x23d kernel/sched/core.c:6798
slab_pre_alloc_hook mm/slab.h:565 [inline]
slab_alloc_node mm/slab.c:3227 [inline]
kmem_cache_alloc_node_trace+0x272/0x790 mm/slab.c:3593
__do_kmalloc_node mm/slab.c:3615 [inline]
__kmalloc_node+0x38/0x60 mm/slab.c:3623
kmalloc_node include/linux/slab.h:578 [inline]
kvmalloc_node+0x61/0xf0 mm/util.c:574
kvmalloc include/linux/mm.h:645 [inline]
kvzalloc include/linux/mm.h:653 [inline]
bucket_table_alloc+0x8b/0x480 lib/rhashtable.c:175
rhashtable_init+0x3d2/0x750 lib/rhashtable.c:1054
nf_flow_table_init+0x16d/0x310 net/netfilter/nf_flow_table_core.c:498
tcf_ct_flow_table_get+0xe33/0x1700 net/sched/act_ct.c:82
tcf_ct_init+0xba4/0x18a6 net/sched/act_ct.c:1050
tcf_action_init_1+0x697/0xa20 net/sched/act_api.c:945
tcf_action_init+0x1e9/0x2f0 net/sched/act_api.c:1001
tcf_action_add+0xdb/0x370 net/sched/act_api.c:1411
tc_ctl_action+0x366/0x456 net/sched/act_api.c:1466
rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5440
netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2478
netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:672
____sys_sendmsg+0x6b9/0x7d0 net/socket.c:2343
___sys_sendmsg+0x100/0x170 net/socket.c:2397
__sys_sendmsg+0xec/0x1b0 net/socket.c:2430
do_syscall_64+0xf6/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4403d9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd719af218 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004403d9
RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000005 R09: 00000000004002c8
R10: 0000000000000008 R11: 00000000000
Fixes:
|
||
---|---|---|
.. | ||
act_api.c | ||
act_bpf.c | ||
act_connmark.c | ||
act_csum.c | ||
act_ct.c | ||
act_ctinfo.c | ||
act_gact.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_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 |