2017-03-01 15:27:10

by Andrey Konovalov

[permalink] [raw]
Subject: net/ipv4: inconsistent lock state in tcp_conn_request/inet_ehash_insert

Hi,

I've got the following error report while fuzzing the kernel with syzkaller.

On commit e5d56efc97f8240d0b5d66c03949382b6d7e5570 (Feb 26).

A reproducer and .config are attached.

=================================
[ INFO: inconsistent lock state ]
4.10.0+ #60 Not tainted
---------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
syz-executor0/5090 [HC0[0]:SC0[0]:HE1:SE1] takes:
(&(&hashinfo->ehash_locks[i])->rlock){+.?...}, at:
[<ffffffff83a6a370>] spin_lock include/linux/spinlock.h:299 [inline]
(&(&hashinfo->ehash_locks[i])->rlock){+.?...}, at:
[<ffffffff83a6a370>] inet_ehash_insert+0x240/0xad0
net/ipv4/inet_hashtables.c:407
{IN-SOFTIRQ-W} state was registered at:
mark_irqflags kernel/locking/lockdep.c:2923 [inline]
__lock_acquire+0xbcf/0x3270 kernel/locking/lockdep.c:3295
lock_acquire+0x241/0x580 kernel/locking/lockdep.c:3753
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:299 [inline]
inet_ehash_insert+0x240/0xad0 net/ipv4/inet_hashtables.c:407
reqsk_queue_hash_req net/ipv4/inet_connection_sock.c:753 [inline]
inet_csk_reqsk_queue_hash_add+0x1b7/0x2a0 net/ipv4/inet_connection_sock.c:764
tcp_conn_request+0x25cc/0x3310 net/ipv4/tcp_input.c:6399
tcp_v4_conn_request+0x157/0x220 net/ipv4/tcp_ipv4.c:1262
tcp_rcv_state_process+0x802/0x4130 net/ipv4/tcp_input.c:5889
tcp_v4_do_rcv+0x56b/0x940 net/ipv4/tcp_ipv4.c:1433
tcp_v4_rcv+0x2e12/0x3210 net/ipv4/tcp_ipv4.c:1711
ip_local_deliver_finish+0x4ce/0xc40 net/ipv4/ip_input.c:216
NF_HOOK include/linux/netfilter.h:257 [inline]
ip_local_deliver+0x1ce/0x710 net/ipv4/ip_input.c:257
dst_input include/net/dst.h:492 [inline]
ip_rcv_finish+0xb1d/0x2110 net/ipv4/ip_input.c:396
NF_HOOK include/linux/netfilter.h:257 [inline]
ip_rcv+0xd90/0x19c0 net/ipv4/ip_input.c:487
__netif_receive_skb_core+0x1ad1/0x3400 net/core/dev.c:4179
__netif_receive_skb+0x2a/0x170 net/core/dev.c:4217
netif_receive_skb_internal+0x1d6/0x430 net/core/dev.c:4245
napi_skb_finish net/core/dev.c:4602 [inline]
napi_gro_receive+0x4e6/0x680 net/core/dev.c:4636
e1000_receive_skb drivers/net/ethernet/intel/e1000/e1000_main.c:4033 [inline]
e1000_clean_rx_irq+0x5e0/0x1490
drivers/net/ethernet/intel/e1000/e1000_main.c:4489
e1000_clean+0xb9a/0x2910 drivers/net/ethernet/intel/e1000/e1000_main.c:3834
napi_poll net/core/dev.c:5171 [inline]
net_rx_action+0xe70/0x1900 net/core/dev.c:5236
__do_softirq+0x2fb/0xb7d kernel/softirq.c:284
invoke_softirq kernel/softirq.c:364 [inline]
irq_exit+0x19e/0x1d0 kernel/softirq.c:405
exiting_irq arch/x86/include/asm/apic.h:658 [inline]
do_IRQ+0x81/0x1a0 arch/x86/kernel/irq.c:250
ret_from_intr+0x0/0x20
native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:53
arch_safe_halt arch/x86/include/asm/paravirt.h:98 [inline]
default_idle+0x8f/0x410 arch/x86/kernel/process.c:271
arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:262
default_idle_call+0x36/0x60 kernel/sched/idle.c:96
cpuidle_idle_call kernel/sched/idle.c:154 [inline]
do_idle+0x348/0x440 kernel/sched/idle.c:243
cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:345
start_secondary+0x344/0x440 arch/x86/kernel/smpboot.c:272
verify_cpu+0x0/0xfc
irq event stamp: 1741
hardirqs last enabled at (1741): [<ffffffff84d49d77>]
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160
[inline]
hardirqs last enabled at (1741): [<ffffffff84d49d77>]
_raw_spin_unlock_irqrestore+0xf7/0x1a0 kernel/locking/spinlock.c:191
hardirqs last disabled at (1740): [<ffffffff84d4a732>]
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
hardirqs last disabled at (1740): [<ffffffff84d4a732>]
_raw_spin_lock_irqsave+0xa2/0x110 kernel/locking/spinlock.c:159
softirqs last enabled at (1738): [<ffffffff84d4deff>]
__do_softirq+0x7cf/0xb7d kernel/softirq.c:310
softirqs last disabled at (1571): [<ffffffff84d4b92c>]
do_softirq_own_stack+0x1c/0x30 arch/x86/entry/entry_64.S:902

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&(&hashinfo->ehash_locks[i])->rlock);
<Interrupt>
lock(&(&hashinfo->ehash_locks[i])->rlock);

*** DEADLOCK ***

1 lock held by syz-executor0/5090:
#0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff83406b43>] lock_sock
include/net/sock.h:1460 [inline]
#0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff83406b43>]
sock_setsockopt+0x233/0x1e40 net/core/sock.c:683

stack backtrace:
CPU: 1 PID: 5090 Comm: syz-executor0 Not tainted 4.10.0+ #60
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:15 [inline]
dump_stack+0x292/0x398 lib/dump_stack.c:51
print_usage_bug+0x3ef/0x450 kernel/locking/lockdep.c:2387
valid_state kernel/locking/lockdep.c:2400 [inline]
mark_lock_irq kernel/locking/lockdep.c:2602 [inline]
mark_lock+0xf30/0x1410 kernel/locking/lockdep.c:3065
mark_irqflags kernel/locking/lockdep.c:2941 [inline]
__lock_acquire+0x6dc/0x3270 kernel/locking/lockdep.c:3295
lock_acquire+0x241/0x580 kernel/locking/lockdep.c:3753
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:299 [inline]
inet_ehash_insert+0x240/0xad0 net/ipv4/inet_hashtables.c:407
reqsk_queue_hash_req net/ipv4/inet_connection_sock.c:753 [inline]
inet_csk_reqsk_queue_hash_add+0x1b7/0x2a0 net/ipv4/inet_connection_sock.c:764
dccp_v6_conn_request+0xada/0x11b0 net/dccp/ipv6.c:380
dccp_rcv_state_process+0x51e/0x1660 net/dccp/input.c:606
dccp_v6_do_rcv+0x213/0x350 net/dccp/ipv6.c:632
sk_backlog_rcv include/net/sock.h:896 [inline]
__release_sock+0x127/0x3a0 net/core/sock.c:2052
release_sock+0xa5/0x2b0 net/core/sock.c:2539
sock_setsockopt+0x60f/0x1e40 net/core/sock.c:1016
SYSC_setsockopt net/socket.c:1782 [inline]
SyS_setsockopt+0x2fb/0x3a0 net/socket.c:1765
entry_SYSCALL_64_fastpath+0x1f/0xc2
RIP: 0033:0x4458b9
RSP: 002b:00007fe8b26c2b58 EFLAGS: 00000292 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00000000004458b9
RDX: 000000000000001a RSI: 0000000000000001 RDI: 0000000000000006
RBP: 00000000006e2110 R08: 0000000000000010 R09: 0000000000000000
R10: 00000000208c3000 R11: 0000000000000292 R12: 0000000000708000
R13: 0000000020000000 R14: 0000000000001000 R15: 0000000000000000


Attachments:
ehash-rcu-info-poc.c (10.67 kB)
.config (124.22 kB)
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2017-03-01 15:23:04

by Eric Dumazet

[permalink] [raw]
Subject: Re: net/ipv4: inconsistent lock state in tcp_conn_request/inet_ehash_insert

On Wed, Mar 1, 2017 at 6:59 AM, Andrey Konovalov <[email protected]> wrote:
> Hi,
>
> I've got the following error report while fuzzing the kernel with syzkaller.
>
> On commit e5d56efc97f8240d0b5d66c03949382b6d7e5570 (Feb 26).

SInce I probably added this bug, I will send a fix shortly, thanks for
the report.