netlink: 1 bytes leftover after parsing attributes in process `syz-executor2'.

======================================================
WARNING: possible circular locking dependency detected
4.15.0-rc3+ #218 Not tainted
------------------------------------------------------
syz-executor4/20910 is trying to acquire lock:
 (&ctx->mutex){+.+.}, at: [<0000000098558e62>] perf_event_ctx_lock_nested+0x21b/0x450 kernel/events/core.c:1249

but task is already holding lock:
 (&pipe->mutex/1){+.+.}, at: [<000000007fb99618>] pipe_lock_nested fs/pipe.c:67 [inline]
 (&pipe->mutex/1){+.+.}, at: [<000000007fb99618>] pipe_lock+0x56/0x70 fs/pipe.c:75

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #8 (&pipe->mutex/1){+.+.}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
       pipe_lock_nested fs/pipe.c:67 [inline]
       pipe_lock+0x56/0x70 fs/pipe.c:75
       iter_file_splice_write+0x264/0xf30 fs/splice.c:699
       do_splice_from fs/splice.c:851 [inline]
       do_splice fs/splice.c:1147 [inline]
       SYSC_splice fs/splice.c:1402 [inline]
       SyS_splice+0x7d5/0x1630 fs/splice.c:1382
       entry_SYSCALL_64_fastpath+0x1f/0x96

-> #7 (sb_writers){.+.+}:
       complete+0x18/0x80 kernel/sched/completion.c:35
       devtmpfsd+0x29b/0x4b0 drivers/base/devtmpfs.c:401
       kthread+0x37a/0x440 kernel/kthread.c:238
       ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:441
       0xffffffffffffffff

-> #6 ((completion)&req.done){+.+.}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       complete_acquire include/linux/completion.h:40 [inline]
       __wait_for_common kernel/sched/completion.c:109 [inline]
       wait_for_common kernel/sched/completion.c:123 [inline]
       wait_for_completion+0xcb/0x7b0 kernel/sched/completion.c:144
       devtmpfs_create_node+0x32b/0x4a0 drivers/base/devtmpfs.c:115
       device_add+0x120f/0x1640 drivers/base/core.c:1824
       device_create_groups_vargs+0x1f3/0x250 drivers/base/core.c:2430
       device_create_vargs drivers/base/core.c:2470 [inline]
       device_create+0xda/0x110 drivers/base/core.c:2506
       msr_device_create+0x26/0x40 arch/x86/kernel/msr.c:188
       cpuhp_invoke_callback+0x2ea/0x1d20 kernel/cpu.c:182
       cpuhp_thread_fun+0x48e/0x7e0 kernel/cpu.c:571
       smpboot_thread_fn+0x450/0x7c0 kernel/smpboot.c:164
       kthread+0x37a/0x440 kernel/kthread.c:238
       ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:441

-> #5 (cpuhp_state-up){+.+.}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       cpuhp_lock_acquire kernel/cpu.c:85 [inline]
       cpuhp_invoke_ap_callback kernel/cpu.c:605 [inline]
       cpuhp_issue_call+0x1e5/0x520 kernel/cpu.c:1495
       __cpuhp_setup_state_cpuslocked+0x282/0x600 kernel/cpu.c:1642
       __cpuhp_setup_state+0xb0/0x140 kernel/cpu.c:1671
       cpuhp_setup_state include/linux/cpuhotplug.h:201 [inline]
       page_writeback_init+0x4d/0x71 mm/page-writeback.c:2081
       pagecache_init+0x48/0x4f mm/filemap.c:977
       start_kernel+0x6bc/0x74f init/main.c:695
       x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378
       x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359
       secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237

-> #4 (cpuhp_state_mutex){+.+.}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
       __cpuhp_setup_state_cpuslocked+0x5b/0x600 kernel/cpu.c:1617
       __cpuhp_setup_state+0xb0/0x140 kernel/cpu.c:1671
       cpuhp_setup_state_nocalls include/linux/cpuhotplug.h:229 [inline]
       kvm_guest_init+0x1f3/0x20f arch/x86/kernel/kvm.c:528
       setup_arch+0x17e8/0x1a02 arch/x86/kernel/setup.c:1266
       start_kernel+0xa5/0x74f init/main.c:530
       x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378
       x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359
       secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237

-> #3 (cpu_hotplug_lock.rw_sem){++++}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline]
       percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
       cpus_read_lock+0x42/0x90 kernel/cpu.c:293
       static_key_slow_inc+0x9d/0x3c0 kernel/jump_label.c:123
       tracepoint_add_func kernel/tracepoint.c:223 [inline]
       tracepoint_probe_register_prio+0x80d/0x9a0 kernel/tracepoint.c:283
       tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:304
       trace_event_reg+0x167/0x320 kernel/trace/trace_events.c:305
       perf_trace_event_reg kernel/trace/trace_event_perf.c:122 [inline]
       perf_trace_event_init kernel/trace/trace_event_perf.c:197 [inline]
       perf_trace_init+0x4ef/0xab0 kernel/trace/trace_event_perf.c:221
       perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:7956
       perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9182
       perf_init_event kernel/events/core.c:9220 [inline]
       perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9484
       SYSC_perf_event_open+0x842/0x2f10 kernel/events/core.c:9939
       SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9825
       entry_SYSCALL_64_fastpath+0x1f/0x96

-> #2 (tracepoints_mutex){+.+.}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
       tracepoint_probe_register_prio+0xa0/0x9a0 kernel/tracepoint.c:279
       tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:304
       trace_event_reg+0x167/0x320 kernel/trace/trace_events.c:305
       perf_trace_event_reg kernel/trace/trace_event_perf.c:122 [inline]
       perf_trace_event_init kernel/trace/trace_event_perf.c:197 [inline]
       perf_trace_init+0x4ef/0xab0 kernel/trace/trace_event_perf.c:221
       perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:7956
       perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9182
       perf_init_event kernel/events/core.c:9220 [inline]
       perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9484
       SYSC_perf_event_open+0x842/0x2f10 kernel/events/core.c:9939
       SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9825
       entry_SYSCALL_64_fastpath+0x1f/0x96

-> #1 (event_mutex){+.+.}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
       perf_trace_init+0x58/0xab0 kernel/trace/trace_event_perf.c:216
       perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:7956
       perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9182
       perf_init_event kernel/events/core.c:9204 [inline]
       perf_event_alloc+0x1005/0x2b00 kernel/events/core.c:9484
       inherit_event.isra.92+0x15b/0x920 kernel/events/core.c:10698
       inherit_group kernel/events/core.c:10789 [inline]
       inherit_task_group.isra.94.part.95+0x73/0x240 kernel/events/core.c:10847
       inherit_task_group kernel/events/core.c:10827 [inline]
       perf_event_init_context kernel/events/core.c:10898 [inline]
       perf_event_init_task+0x348/0x890 kernel/events/core.c:10966
       copy_process.part.36+0x173b/0x4ae0 kernel/fork.c:1727
       copy_process kernel/fork.c:1566 [inline]
       _do_fork+0x1ef/0xff0 kernel/fork.c:2045
       SYSC_clone kernel/fork.c:2155 [inline]
       SyS_clone+0x37/0x50 kernel/fork.c:2149
       do_syscall_64+0x26c/0x920 arch/x86/entry/common.c:285
       return_from_SYSCALL_64+0x0/0x75

-> #0 (&ctx->mutex){+.+.}:
       check_prevs_add kernel/locking/lockdep.c:2031 [inline]
       validate_chain kernel/locking/lockdep.c:2473 [inline]
       __lock_acquire+0x3498/0x47f0 kernel/locking/lockdep.c:3500
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
       perf_event_ctx_lock_nested+0x21b/0x450 kernel/events/core.c:1249
       perf_event_ctx_lock kernel/events/core.c:1262 [inline]
       perf_read+0xb9/0x970 kernel/events/core.c:4507
       do_loop_readv_writev fs/read_write.c:673 [inline]
       do_iter_read+0x3db/0x5b0 fs/read_write.c:897
       vfs_readv+0x121/0x1c0 fs/read_write.c:959
       kernel_readv fs/splice.c:361 [inline]
       default_file_splice_read+0x508/0xae0 fs/splice.c:416
       do_splice_to+0x110/0x170 fs/splice.c:880
       do_splice fs/splice.c:1173 [inline]
       SYSC_splice fs/splice.c:1402 [inline]
       SyS_splice+0x11a8/0x1630 fs/splice.c:1382
       entry_SYSCALL_64_fastpath+0x1f/0x96

other info that might help us debug this:

Chain exists of:
  &ctx->mutex --> sb_writers --> &pipe->mutex/1

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&pipe->mutex/1);
                               lock(sb_writers);
                               lock(&pipe->mutex/1);
  lock(&ctx->mutex);

 *** DEADLOCK ***

1 lock held by syz-executor4/20910:
 #0:  (&pipe->mutex/1){+.+.}, at: [<000000007fb99618>] pipe_lock_nested fs/pipe.c:67 [inline]
 #0:  (&pipe->mutex/1){+.+.}, at: [<000000007fb99618>] pipe_lock+0x56/0x70 fs/pipe.c:75

stack backtrace:
CPU: 0 PID: 20910 Comm: syz-executor4 Not tainted 4.15.0-rc3+ #218
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+0x194/0x257 lib/dump_stack.c:53
 print_circular_bug+0x42d/0x610 kernel/locking/lockdep.c:1271
 check_prev_add+0x666/0x15f0 kernel/locking/lockdep.c:1914
 check_prevs_add kernel/locking/lockdep.c:2031 [inline]
 validate_chain kernel/locking/lockdep.c:2473 [inline]
 __lock_acquire+0x3498/0x47f0 kernel/locking/lockdep.c:3500
 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
 __mutex_lock_common kernel/locking/mutex.c:756 [inline]
 __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
 perf_event_ctx_lock_nested+0x21b/0x450 kernel/events/core.c:1249
 perf_event_ctx_lock kernel/events/core.c:1262 [inline]
 perf_read+0xb9/0x970 kernel/events/core.c:4507
 do_loop_readv_writev fs/read_write.c:673 [inline]
 do_iter_read+0x3db/0x5b0 fs/read_write.c:897
 vfs_readv+0x121/0x1c0 fs/read_write.c:959
 kernel_readv fs/splice.c:361 [inline]
 default_file_splice_read+0x508/0xae0 fs/splice.c:416
 do_splice_to+0x110/0x170 fs/splice.c:880
 do_splice fs/splice.c:1173 [inline]
 SYSC_splice fs/splice.c:1402 [inline]
 SyS_splice+0x11a8/0x1630 fs/splice.c:1382
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a39
RSP: 002b:00007f47437b4c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39
RDX: 0000000000000017 RSI: 0000000000000000 RDI: 0000000000000018
RBP: 00000000000001f7 R08: 0000000100000001 R09: 000000000000000e
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f0fc8
R13: 00000000ffffffff R14: 00007f47437b56d4 R15: 0000000000000000
QAT: Invalid ioctl
QAT: Invalid ioctl
netlink: 1 bytes leftover after parsing attributes in process `syz-executor2'.
dccp_invalid_packet: P.CsCov 5 exceeds packet length 552
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=21048 comm=syz-executor7
dccp_invalid_packet: P.CsCov 5 exceeds packet length 552
print_req_error: I/O error, dev loop3, sector 0
Buffer I/O error on dev loop3, logical block 0, lost async page write
print_req_error: I/O error, dev loop3, sector 1
Buffer I/O error on dev loop3, logical block 1, lost async page write
print_req_error: I/O error, dev loop3, sector 2
Buffer I/O error on dev loop3, logical block 2, lost async page write
print_req_error: I/O error, dev loop3, sector 3
Buffer I/O error on dev loop3, logical block 3, lost async page write
print_req_error: I/O error, dev loop3, sector 4
Buffer I/O error on dev loop3, logical block 4, lost async page write
print_req_error: I/O error, dev loop3, sector 5
Buffer I/O error on dev loop3, logical block 5, lost async page write
print_req_error: I/O error, dev loop3, sector 6
Buffer I/O error on dev loop3, logical block 6, lost async page write
print_req_error: I/O error, dev loop3, sector 7
Buffer I/O error on dev loop3, logical block 7, lost async page write
print_req_error: I/O error, dev loop3, sector 8
Buffer I/O error on dev loop3, logical block 8, lost async page write
print_req_error: I/O error, dev loop3, sector 9
Buffer I/O error on dev loop3, logical block 9, lost async page write
netlink: 1 bytes leftover after parsing attributes in process `syz-executor3'.
sg_write: data in/out 1562545402/1 bytes for SCSI command 0x0-- guessing data in;
   program syz-executor5 not setting count and/or reply_len properly
sg_write: data in/out 822404280/197 bytes for SCSI command 0x12-- guessing data in;
   program syz-executor5 not setting count and/or reply_len properly
sg_write: data in/out 1562545402/1 bytes for SCSI command 0x0-- guessing data in;
   program syz-executor5 not setting count and/or reply_len properly
sg_write: data in/out 822404280/197 bytes for SCSI command 0x12-- guessing data in;
   program syz-executor5 not setting count and/or reply_len properly
netlink: 1 bytes leftover after parsing attributes in process `syz-executor3'.
sctp: [Deprecated]: syz-executor4 (pid 21199) Use of int in maxseg socket option.
Use struct sctp_assoc_value instead
sctp: [Deprecated]: syz-executor4 (pid 21212) Use of int in maxseg socket option.
Use struct sctp_assoc_value instead
rfkill: input handler disabled
rfkill: input handler enabled
binder: BINDER_SET_CONTEXT_MGR already set
binder: 21261:21275 ioctl 40046207 0 returned -16
device gre0 entered promiscuous mode
QAT: Invalid ioctl
QAT: Invalid ioctl
SELinux: unrecognized netlink message: protocol=9 nlmsg_type=25 sclass=netlink_audit_socket pig=21555 comm=syz-executor2
QAT: Invalid ioctl
QAT: Invalid ioctl
SELinux: unrecognized netlink message: protocol=9 nlmsg_type=25 sclass=netlink_audit_socket pig=21567 comm=syz-executor2
device gre0 entered promiscuous mode
loop_reread_partitions: partition scan of loop0 (2°]€fI¸Òæ¶Ì”B±!S,›ùDÏ') failed (rc=-13)
loop_reread_partitions: partition scan of loop0 () failed (rc=-13)
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 22461 Comm: syz-executor1 Not tainted 4.15.0-rc3+ #218
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+0x194/0x257 lib/dump_stack.c:53
 fail_dump lib/fault-inject.c:51 [inline]
 should_fail+0x8c0/0xa40 lib/fault-inject.c:149
 should_failslab+0xec/0x120 mm/failslab.c:32
 slab_pre_alloc_hook mm/slab.h:421 [inline]
 slab_alloc mm/slab.c:3371 [inline]
 kmem_cache_alloc+0x47/0x760 mm/slab.c:3545
 kmem_cache_zalloc include/linux/slab.h:678 [inline]
 locks_alloc_lock+0x86/0x260 fs/locks.c:312
 lease_alloc+0x20/0x2b0 fs/locks.c:581
 do_fcntl_add_lease fs/locks.c:1894 [inline]
 fcntl_setlease+0xaa/0x350 fs/locks.c:1927
 do_fcntl+0x58c/0x1160 fs/fcntl.c:410
 SYSC_fcntl fs/fcntl.c:463 [inline]
 SyS_fcntl+0xdc/0x120 fs/fcntl.c:448
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a39
RSP: 002b:00007fb06c24ec58 EFLAGS: 00000212 ORIG_RAX: 0000000000000048
RAX: ffffffffffffffda RBX: 00007fb06c24eaa0 RCX: 0000000000452a39
RDX: 0000000000000000 RSI: 0000000000000400 RDI: 0000000000000014
RBP: 00007fb06c24ea90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000004b75fb
R13: 00007fb06c24ebc8 R14: 00000000004b75fb R15: 0000000000000000
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 22510 Comm: syz-executor4 Not tainted 4.15.0-rc3+ #218
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+0x194/0x257 lib/dump_stack.c:53
 fail_dump lib/fault-inject.c:51 [inline]
 should_fail+0x8c0/0xa40 lib/fault-inject.c:149
 should_failslab+0xec/0x120 mm/failslab.c:32
 slab_pre_alloc_hook mm/slab.h:421 [inline]
 slab_alloc mm/slab.c:3371 [inline]
 kmem_cache_alloc+0x47/0x760 mm/slab.c:3545
 create_nsproxy kernel/nsproxy.c:53 [inline]
 create_new_namespaces+0x88/0x880 kernel/nsproxy.c:71
 SYSC_setns kernel/nsproxy.c:254 [inline]
 SyS_setns+0x1b3/0x2d0 kernel/nsproxy.c:237
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a39
RSP: 002b:00007f47437b4c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000134
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000013
RBP: 00000000000005bf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f6a88
R13: 00000000ffffffff R14: 00007f47437b56d4 R15: 0000000000000000
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 22714 Comm: syz-executor7 Not tainted 4.15.0-rc3+ #218
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+0x194/0x257 lib/dump_stack.c:53
 fail_dump lib/fault-inject.c:51 [inline]
 should_fail+0x8c0/0xa40 lib/fault-inject.c:149
 should_failslab+0xec/0x120 mm/failslab.c:32
 slab_pre_alloc_hook mm/slab.h:421 [inline]
 slab_alloc mm/slab.c:3371 [inline]
 kmem_cache_alloc+0x47/0x760 mm/slab.c:3545
 create_nsproxy kernel/nsproxy.c:53 [inline]
 create_new_namespaces+0x88/0x880 kernel/nsproxy.c:71
 SYSC_setns kernel/nsproxy.c:254 [inline]
 SyS_setns+0x1b3/0x2d0 kernel/nsproxy.c:237
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a39
RSP: 002b:00007f17185b9c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000134
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000014
RBP: 00000000000005bf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f6a88
R13: 00000000ffffffff R14: 00007f17185ba6d4 R15: 0000000000000000
kauditd_printk_skb: 135 callbacks suppressed
audit: type=1400 audit(1513050210.944:2244): avc:  denied  { map } for  pid=23150 comm="syz-executor4" path="mnt:[4026532427]" dev="nsfs" ino=4026532427 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:unlabeled_t:s0 tclass=file permissive=1