WARNING in __local_bh_enable_ip (2)

[syzbot]

Hello,

syzbot hit the following crash on net-next commit
be9fc0971a5c27b791608cf9705a04fe96dbd395 (Tue Mar 13 11:44:53 2018 +0000)
net: fix sysctl_fb_tunnels_only_for_init_net link error

So far this crash happened 2 times on net-next.
Unfortunately, I don't have any reproducer for this crash yet.
Raw console output is attached.
compiler: gcc (GCC) 7.1.1 20170620
.config is attached.

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Reported-by: syzbot+c68e51...@syzkaller.appspotmail.com
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------------[ cut here ]------------
IRQs not enabled as expected
WARNING: CPU: 1 PID: 21587 at kernel/softirq.c:162
__local_bh_enable_ip+0x1bb/0x230 kernel/softirq.c:162
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 21587 Comm: syz-executor6 Not tainted 4.16.0-rc4+ #264
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
panic+0x1e4/0x41c kernel/panic.c:183
__warn+0x1dc/0x200 kernel/panic.c:547
syz-executor7: vmalloc: allocation failure: 17045651456 bytes,
mode:0x14080c0(GFP_KERNEL|__GFP_ZERO), nodemask=(null)
report_bug+0x211/0x2d0 lib/bug.c:184
fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178
fixup_bug arch/x86/kernel/traps.c:247 [inline]
do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296
syz-executor7 cpuset=
/
do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
mems_allowed=0
invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986
RIP: 0010:__local_bh_enable_ip+0x1bb/0x230 kernel/softirq.c:162
RSP: 0018:ffff8801c95f71e0 EFLAGS: 00010082
RAX: dffffc0000000008 RBX: 0000000000000201 RCX: ffffffff815abf2e
RDX: 00000000000037b0 RSI: ffffc900045ec000 RDI: 1ffff100392bedc1
RBP: ffff8801c95f71f8 R08: 0000000000000000 R09: 1ffff100392bed93
R10: ffff8801c95f70d8 R11: 0000000000000002 R12: ffffffff85638c44
R13: ffff8801bb9fc080 R14: ffff8801c95f7290 R15: 1ffff100392bee4a
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline]
_raw_spin_unlock_bh+0x30/0x40 kernel/locking/spinlock.c:200
spin_unlock_bh include/linux/spinlock.h:355 [inline]
rds_tcp_conn_free+0xa4/0x2d0 net/rds/tcp.c:281
__rds_conn_create+0x148f/0x1b60 net/rds/connection.c:277
rds_conn_create_outgoing+0x3f/0x50 net/rds/connection.c:309
rds_sendmsg+0xe63/0x2590 net/rds/send.c:1156
sock_sendmsg_nosec net/socket.c:629 [inline]
sock_sendmsg+0xca/0x110 net/socket.c:639
___sys_sendmsg+0x767/0x8b0 net/socket.c:2047
__sys_sendmsg+0xe5/0x210 net/socket.c:2081
SYSC_sendmsg net/socket.c:2092 [inline]
SyS_sendmsg+0x2d/0x50 net/socket.c:2088
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x453e69
RSP: 002b:00007f102cbd0c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f102cbd16d4 RCX: 0000000000453e69
RDX: 0000000000000000 RSI: 0000000020001580 RDI: 0000000000000014
RBP: 000000000072bf58 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000004b9 R14: 00000000006f71f8 R15: 0000000000000001
CPU: 0 PID: 21594 Comm: syz-executor7 Not tainted 4.16.0-rc4+ #264
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
warn_alloc+0x19a/0x2b0 mm/page_alloc.c:3310
__vmalloc_node_range+0x4f0/0x650 mm/vmalloc.c:1775
__vmalloc_node mm/vmalloc.c:1804 [inline]
__vmalloc_node_flags_caller+0x50/0x60 mm/vmalloc.c:1826
kvmalloc_node+0x82/0xd0 mm/util.c:428
kvmalloc include/linux/mm.h:541 [inline]
kvmalloc_array include/linux/mm.h:557 [inline]
xt_alloc_entry_offsets+0x21/0x30 net/netfilter/x_tables.c:778
translate_table+0x235/0x1690 net/ipv6/netfilter/ip6_tables.c:703
do_replace net/ipv6/netfilter/ip6_tables.c:1164 [inline]
do_ip6t_set_ctl+0x370/0x5f0 net/ipv6/netfilter/ip6_tables.c:1690
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ipv6_setsockopt+0x10b/0x130 net/ipv6/ipv6_sockglue.c:927
tcp_setsockopt+0x82/0xd0 net/ipv4/tcp.c:2878
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2980
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x453e69
RSP: 002b:00007f0cd3439c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f0cd343a6d4 RCX: 0000000000453e69
RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000014
RBP: 000000000072bea0 R08: 0000000000000004 R09: 0000000000000000
R10: 0000000020001fde R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000520 R14: 00000000006f7ba0 R15: 0000000000000000
Dumping ftrace buffer:
(ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..


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[Eric Dumazet]

spin_lock_bh(&rds_tcp_conn_lock);/spin_unlock_bh(&rds_tcp_conn_lock);
in rds_tcp_conn_free()

is in conflict with the spin_lock_irqsave(&rds_conn_lock, flags);
in __rds_conn_create()

Hard to understand why RDS is messing with hard irqs really.

[Sowmini Varadhan]

On (03/14/18 14:28), Eric Dumazet wrote:
>
>
> spin_lock_bh(&rds_tcp_conn_lock);/spin_unlock_bh(&rds_tcp_conn_lock); in
> rds_tcp_conn_free()
>
> is in conflict with the spin_lock_irqsave(&rds_conn_lock, flags);
> in __rds_conn_create()

yes I was going to look into this and fix it later.

> Hard to understand why RDS is messing with hard irqs really.

some of it comes from the rds_rdma history: some parts of
the common rds and rds_rdma module get called in various
driver contexts for infiniband.

--Sowmini