INFO: task hung in ovs_dp_cmd_new

From: syzbot
Date: Tue Sep 17 2019 - 02:54:09 EST


Hello,

syzbot found the following crash on:

HEAD commit: 2339cd6c bpf: fix precision tracking of stack slots
git tree: bpf
console output: https://syzkaller.appspot.com/x/log.txt?x=14707b01600000
kernel config: https://syzkaller.appspot.com/x/.config?x=b89bb446a3faaba4
dashboard link: https://syzkaller.appspot.com/bug?extid=a9d62dbe662772066f3c
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+a9d62dbe662772066f3c@xxxxxxxxxxxxxxxxxxxxxxxxx

INFO: task syz-executor.0:3410 blocked for more than 143 seconds.
Not tainted 5.3.0-rc7+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0 D26056 3410 18433 0x00000004
Call Trace:
context_switch kernel/sched/core.c:3254 [inline]
__schedule+0x755/0x1580 kernel/sched/core.c:3880
schedule+0xd9/0x260 kernel/sched/core.c:3947
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4006
__mutex_lock_common kernel/locking/mutex.c:1007 [inline]
__mutex_lock+0x7b0/0x13c0 kernel/locking/mutex.c:1077
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1092
ovs_lock net/openvswitch/datapath.c:105 [inline]
ovs_dp_cmd_new+0x579/0xea0 net/openvswitch/datapath.c:1613
genl_family_rcv_msg+0x74b/0xf90 net/netlink/genetlink.c:629
genl_rcv_msg+0xca/0x170 net/netlink/genetlink.c:654
netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
genl_rcv+0x29/0x40 net/netlink/genetlink.c:665
netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1328
netlink_sendmsg+0x8a5/0xd60 net/netlink/af_netlink.c:1917
sock_sendmsg_nosec net/socket.c:637 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:657
___sys_sendmsg+0x803/0x920 net/socket.c:2311
__sys_sendmsg+0x105/0x1d0 net/socket.c:2356
__do_sys_sendmsg net/socket.c:2365 [inline]
__se_sys_sendmsg net/socket.c:2363 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2363
do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4598e9
Code: Bad RIP value.
RSP: 002b:00007fa2501cdc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004598e9
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000004
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa2501ce6d4
R13: 00000000004c7777 R14: 00000000004dcfd8 R15: 00000000ffffffff
INFO: task syz-executor.0:3414 blocked for more than 143 seconds.
Not tainted 5.3.0-rc7+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0 D26136 3414 18433 0x00000004
Call Trace:
context_switch kernel/sched/core.c:3254 [inline]
__schedule+0x755/0x1580 kernel/sched/core.c:3880
schedule+0xd9/0x260 kernel/sched/core.c:3947
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4006
__mutex_lock_common kernel/locking/mutex.c:1007 [inline]
__mutex_lock+0x7b0/0x13c0 kernel/locking/mutex.c:1077
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1092
ovs_lock net/openvswitch/datapath.c:105 [inline]
ovs_dp_cmd_new+0x579/0xea0 net/openvswitch/datapath.c:1613
genl_family_rcv_msg+0x74b/0xf90 net/netlink/genetlink.c:629
genl_rcv_msg+0xca/0x170 net/netlink/genetlink.c:654
netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
genl_rcv+0x29/0x40 net/netlink/genetlink.c:665
netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1328
netlink_sendmsg+0x8a5/0xd60 net/netlink/af_netlink.c:1917
sock_sendmsg_nosec net/socket.c:637 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:657
___sys_sendmsg+0x803/0x920 net/socket.c:2311
__sys_sendmsg+0x105/0x1d0 net/socket.c:2356
__do_sys_sendmsg net/socket.c:2365 [inline]
__se_sys_sendmsg net/socket.c:2363 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2363
do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4598e9
Code: Bad RIP value.
RSP: 002b:00007fa2501acc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004598e9
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000006
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa2501ad6d4
R13: 00000000004c7777 R14: 00000000004dcfd8 R15: 00000000ffffffff
INFO: task syz-executor.0:3416 blocked for more than 144 seconds.
Not tainted 5.3.0-rc7+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0 D25968 3416 18433 0x00000004
Call Trace:
context_switch kernel/sched/core.c:3254 [inline]
__schedule+0x755/0x1580 kernel/sched/core.c:3880
schedule+0xd9/0x260 kernel/sched/core.c:3947
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4006
__mutex_lock_common kernel/locking/mutex.c:1007 [inline]
__mutex_lock+0x7b0/0x13c0 kernel/locking/mutex.c:1077
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1092
ovs_lock net/openvswitch/datapath.c:105 [inline]
ovs_dp_cmd_new+0x579/0xea0 net/openvswitch/datapath.c:1613
genl_family_rcv_msg+0x74b/0xf90 net/netlink/genetlink.c:629
genl_rcv_msg+0xca/0x170 net/netlink/genetlink.c:654
netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
genl_rcv+0x29/0x40 net/netlink/genetlink.c:665
netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1328
netlink_sendmsg+0x8a5/0xd60 net/netlink/af_netlink.c:1917
sock_sendmsg_nosec net/socket.c:637 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:657
___sys_sendmsg+0x803/0x920 net/socket.c:2311
__sys_sendmsg+0x105/0x1d0 net/socket.c:2356
__do_sys_sendmsg net/socket.c:2365 [inline]
__se_sys_sendmsg net/socket.c:2363 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2363
do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4598e9
Code: 24 18 0f b6 05 2f d1 3b 01 3c 01 76 0a 48 8b 6c 24 18 48 83 c4 20 c3 75 07 e8 63 08 fd ff 0f 0b c6 05 11 d1 3b 01 01 48 b8 00 <00> 00 00 00 00 f0 7f 48 89 04 24 e8 a7 dd fa ff f2 0f 10 44 24 08
RSP: 002b:00007fa25018bc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004598e9
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000007
RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa25018c6d4
R13: 00000000004c7777 R14: 00000000004dcfd8 R15: 00000000ffffffff
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 PID: 1057 Comm: khungtaskd Not tainted 5.3.0-rc7+ #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+0x172/0x1f0 lib/dump_stack.c:113
nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
watchdog+0x9d0/0xef0 kernel/hung_task.c:289
kthread+0x361/0x430 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60


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