possible deadlock in perf_trace_init (2)

[syzbot]

Hello,

syzkaller hit the following crash on
d127129e85a020879f334154300ddd3f7ec21c1e
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master
compiler: gcc (GCC) 7.1.1 20170620
.config is attached
Raw console output is attached.

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



======================================================
WARNING: possible circular locking dependency detected
4.15.0-rc1-next-20171129+ #55 Not tainted
------------------------------------------------------
syz-executor1/4270 is trying to acquire lock:
(event_mutex){+.+.}, at: [<ffffffff817809f8>] perf_trace_init+0x58/0xab0
kernel/trace/trace_event_perf.c:216

but task is already holding lock:
(&ctx->mutex){+.+.}, at: [<ffffffff818740eb>] perf_event_init_context
kernel/events/core.c:10898 [inline]
(&ctx->mutex){+.+.}, at: [<ffffffff818740eb>]
perf_event_init_task+0x25b/0x890 kernel/events/core.c:10973

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #8 (&ctx->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_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

-> #7 (&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

-> #6 (sb_writers){.+.+}:
finish_lock_switch kernel/sched/sched.h:1360 [inline]
finish_task_switch+0x1aa/0x740 kernel/sched/core.c:2667

-> #5 ((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:517

-> #4 (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:976
start_kernel+0x6bc/0x74f init/main.c:698
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 (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:533
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

-> #2 (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:222 [inline]
tracepoint_probe_register_prio+0x80d/0x9a0 kernel/tracepoint.c:282
tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:303
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:9189
perf_init_event kernel/events/core.c:9227 [inline]
perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9491
SYSC_perf_event_open+0x84e/0x2e00 kernel/events/core.c:9946
SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9832
entry_SYSCALL_64_fastpath+0x1f/0x96

-> #1 (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:278
tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:303
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:9189
perf_init_event kernel/events/core.c:9227 [inline]
perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9491
SYSC_perf_event_open+0x84e/0x2e00 kernel/events/core.c:9946
SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9832
entry_SYSCALL_64_fastpath+0x1f/0x96

-> #0 (event_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_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:9189
perf_init_event kernel/events/core.c:9211 [inline]
perf_event_alloc+0x1005/0x2b00 kernel/events/core.c:9491
inherit_event.isra.92+0x15b/0x920 kernel/events/core.c:10705
inherit_group kernel/events/core.c:10796 [inline]
inherit_task_group.isra.94.part.95+0x73/0x240
kernel/events/core.c:10854
inherit_task_group kernel/events/core.c:10834 [inline]
perf_event_init_context kernel/events/core.c:10905 [inline]
perf_event_init_task+0x348/0x890 kernel/events/core.c:10973
copy_process.part.35+0x1748/0x4b30 kernel/fork.c:1776
copy_process kernel/fork.c:1615 [inline]
_do_fork+0x1ef/0xf10 kernel/fork.c:2096
SYSC_clone kernel/fork.c:2203 [inline]
SyS_clone+0x37/0x50 kernel/fork.c:2197
do_syscall_64+0x26c/0x920 arch/x86/entry/common.c:285
return_from_SYSCALL_64+0x0/0x75

other info that might help us debug this:

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

Possible unsafe locking scenario:

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

*** DEADLOCK ***

2 locks held by syz-executor1/4270:
#0: (&ctx->mutex){+.+.}, at: [<ffffffff818740eb>] perf_event_init_context
kernel/events/core.c:10898 [inline]
#0: (&ctx->mutex){+.+.}, at: [<ffffffff818740eb>]
perf_event_init_task+0x25b/0x890 kernel/events/core.c:10973
#1: (&pmus_srcu){....}, at: [<ffffffff818570b5>]
perf_event_alloc+0xf55/0x2b00 kernel/events/core.c:9487

stack backtrace:
CPU: 1 PID: 4270 Comm: syz-executor1 Not tainted 4.15.0-rc1-next-20171129+
#55
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_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:9189
perf_init_event kernel/events/core.c:9211 [inline]
perf_event_alloc+0x1005/0x2b00 kernel/events/core.c:9491
inherit_event.isra.92+0x15b/0x920 kernel/events/core.c:10705
inherit_group kernel/events/core.c:10796 [inline]
inherit_task_group.isra.94.part.95+0x73/0x240 kernel/events/core.c:10854
inherit_task_group kernel/events/core.c:10834 [inline]
perf_event_init_context kernel/events/core.c:10905 [inline]
perf_event_init_task+0x348/0x890 kernel/events/core.c:10973
copy_process.part.35+0x1748/0x4b30 kernel/fork.c:1776
copy_process kernel/fork.c:1615 [inline]
_do_fork+0x1ef/0xf10 kernel/fork.c:2096
SYSC_clone kernel/fork.c:2203 [inline]
SyS_clone+0x37/0x50 kernel/fork.c:2197
do_syscall_64+0x26c/0x920 arch/x86/entry/common.c:285
entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x455369
RSP: 002b:0000000000a6f748 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f790b89c700 RCX: 0000000000455369
RDX: 00007f790b89c9d0 RSI: 00007f790b89bdb0 RDI: 00000000003d0f00
RBP: 0000000000a6f880 R08: 00007f790b89c700 R09: 00007f790b89c700
R10: 00007f790b89c9d0 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000a6f7ff R14: 00007f790b89c9c0 R15: 0000000000000014
rfkill: input handler disabled
rfkill: input handler enabled
device lo entered promiscuous mode
encrypted_key: insufficient parameters specified
encrypted_key: insufficient parameters specified
device gre0 entered promiscuous mode
print_req_error: I/O error, dev loop0, sector 4
print_req_error: I/O error, dev loop0, sector 4
binder: 4590:4594 transaction failed 29189/-22, size 0-32 line 2832
binder: 4590:4594 transaction failed 29189/-22, size 0-32 line 2832
kauditd_printk_skb: 427 callbacks suppressed
audit: type=1326 audit(1511971831.715:438): auid=4294967295 uid=0 gid=0
ses=4294967295 subj=kernel pid=4761 comm="syz-executor0"
exe="/root/syz-executor0" sig=31 arch=c000003e syscall=202 compat=0
ip=0x4529d9 code=0xffff0000
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4825 comm=syz-executor0
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4834 comm=syz-executor0
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4834 comm=syz-executor0
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4834 comm=syz-executor0
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4834 comm=syz-executor0
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4834 comm=syz-executor0
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 1
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4888 comm=syz-executor0
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4888 comm=syz-executor0
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4888 comm=syz-executor0
CPU: 1 PID: 4882 Comm: syz-executor1 Not tainted 4.15.0-rc1-next-20171129+
#55
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:425 [inline]
slab_alloc mm/slab.c:3372 [inline]
kmem_cache_alloc+0x47/0x760 mm/slab.c:3546
ptlock_alloc+0x24/0x70 mm/memory.c:4673
ptlock_init include/linux/mm.h:1790 [inline]
pgtable_page_ctor include/linux/mm.h:1824 [inline]
pte_alloc_one+0x59/0x100 arch/x86/mm/pgtable.c:32
do_huge_pmd_anonymous_page+0xbbe/0x19e0 mm/huge_memory.c:692
create_huge_pmd mm/memory.c:3816 [inline]
__handle_mm_fault+0x1bd6/0x3e60 mm/memory.c:4019
handle_mm_fault+0x38f/0x930 mm/memory.c:4085
__do_page_fault+0x5c9/0xc90 arch/x86/mm/fault.c:1429
do_page_fault+0xee/0x720 arch/x86/mm/fault.c:1504
page_fault+0x4c/0x60 arch/x86/entry/entry_64.S:1230
RIP: 0033:0x401819
RSP: 002b:00007f790b8bcb90 EFLAGS: 00010246
RAX: 0000000020000000 RBX: 000000000000004a RCX: 0000000000000000
RDX: 209c2a81117b8a5f RSI: 0000000000000000 RDI: 00007f790b8bd608
RBP: 000000002078d000 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000004a R11: 0000000000000000 R12: 00000000006f54e8
R13: 0000000000000013 R14: 00007f790b8bd6d4 R15: ffffffffffffffff
oom_reaper: reaped process 4882 (syz-executor1), now anon-rss:0kB,
file-rss:0kB, shmem-rss:0kB
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4888 comm=syz-executor0
QAT: Invalid ioctl
QAT: Invalid ioctl
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 5697 Comm: syz-executor7 Not tainted 4.15.0-rc1-next-20171129+
#55
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:425 [inline]
slab_alloc mm/slab.c:3372 [inline]
kmem_cache_alloc+0x47/0x760 mm/slab.c:3546
ptlock_alloc+0x24/0x70 mm/memory.c:4673
ptlock_init include/linux/mm.h:1790 [inline]
pgtable_page_ctor include/linux/mm.h:1824 [inline]
pte_alloc_one+0x59/0x100 arch/x86/mm/pgtable.c:32
__do_huge_pmd_anonymous_page mm/huge_memory.c:567 [inline]
do_huge_pmd_anonymous_page+0x554/0x19e0 mm/huge_memory.c:731
create_huge_pmd mm/memory.c:3816 [inline]
__handle_mm_fault+0x1bd6/0x3e60 mm/memory.c:4019
handle_mm_fault+0x38f/0x930 mm/memory.c:4085
__do_page_fault+0x5c9/0xc90 arch/x86/mm/fault.c:1429
do_page_fault+0xee/0x720 arch/x86/mm/fault.c:1504
page_fault+0x2c/0x60 arch/x86/entry/entry_64.S:1230
RIP: 0010:copy_user_enhanced_fast_string+0xe/0x20
arch/x86/lib/copy_user_64.S:180
RSP: 0018:ffff8801c917fd88 EFLAGS: 00010202
RAX: ffffed003922ffda RBX: 0000000000000078 RCX: 0000000000000078
RDX: 0000000000000078 RSI: ffff8801c917fe58 RDI: 0000000020dcbfbc
RBP: ffff8801c917fdb8 R08: ffffed003922ffda R09: ffffed003922ffda
R10: 000000000000000f R11: ffffed003922ffd9 R12: 0000000020dcbfbc
R13: ffff8801c917fe58 R14: 00007ffffffff000 R15: 0000000020dcc034
copy_to_user include/linux/uaccess.h:155 [inline]
copy_msqid_to_user.constprop.9+0x22/0x30 ipc/msg.c:288
SYSC_msgctl+0x212/0x290 ipc/msg.c:557
SyS_msgctl+0x24/0x30 ipc/msg.c:528
entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x4529d9
RSP: 002b:00007f7af2813c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000047
RAX: ffffffffffffffda RBX: 00007f7af2813aa0 RCX: 00000000004529d9
RDX: 0000000020dcbfbc RSI: 0000000000000002 RDI: 0000000000000000
RBP: 00007f7af2813a90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000004b759b
R13: 00007f7af2813bc8 R14: 00000000004b759b R15: 0000000000000000
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 5810 Comm: syz-executor2 Not tainted 4.15.0-rc1-next-20171129+
#55
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:425 [inline]
slab_alloc mm/slab.c:3372 [inline]
kmem_cache_alloc+0x47/0x760 mm/slab.c:3546
__sigqueue_alloc+0x329/0x660 kernel/signal.c:386
__send_signal+0x2e8/0x17a0 kernel/signal.c:1041
send_signal+0x4a/0xc0 kernel/signal.c:1107
specific_send_sig_info kernel/signal.c:1152 [inline]
force_sig_info+0x242/0x340 kernel/signal.c:1204
force_sig_info_fault.constprop.32+0x289/0x450 arch/x86/mm/fault.c:223
__bad_area_nosemaphore+0x1d2/0x3e0 arch/x86/mm/fault.c:923
__bad_area+0x151/0x1f0 arch/x86/mm/fault.c:957
bad_area_access_error+0x166/0x240 arch/x86/mm/fault.c:996
__do_page_fault+0x3d1/0xc90 arch/x86/mm/fault.c:1409
do_page_fault+0xee/0x720 arch/x86/mm/fault.c:1504
page_fault+0x4c/0x60 arch/x86/entry/entry_64.S:1230
RIP: 0033:0x44c5a0
RSP: 002b:00007f771dbdd788 EFLAGS: 00010206
RAX: 00007f771dbdd830 RBX: 0000000000758020 RCX: 0000000000000003
RDX: 0000000000000400 RSI: 0000000020fd7ff0 RDI: 00007f771dbdd830
RBP: 00000000000005a5 R08: 0000000000000400 R09: 0000000000000000
R10: 0000000020fd7ff3 R11: 0000000000000000 R12: 00000000006f5818
R13: 0000000000000014 R14: 00007f771dbde6d4 R15: ffffffffffffffff
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 5826 Comm: syz-executor2 Not tainted 4.15.0-rc1-next-20171129+
#55
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:425 [inline]
slab_alloc mm/slab.c:3372 [inline]
kmem_cache_alloc+0x47/0x760 mm/slab.c:3546
getname_flags+0xcb/0x580 fs/namei.c:138
getname+0x19/0x20 fs/namei.c:209
do_sys_open+0x2e7/0x6d0 fs/open.c:1053
SYSC_open fs/open.c:1077 [inline]
SyS_open+0x2d/0x40 fs/open.c:1072
entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x40cd11
RSP: 002b:00007f771dbdd780 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 000000000040cd11
RDX: 0000000000000000 RSI: 0000000072be4c3d RDI: 00007f771dbdd830
RBP: 00000000000005a5 R08: 00007f771dbdd790 R09: 00000000000005a5
R10: 0000000020fd7ff3 R11: 0000000000000293 R12: 00000000006f5818
R13: 0000000000000014 R14: 00007f771dbde6d4 R15: ffffffffffffffff
FAULT_INJECTION: forcing a failure.
name fail_page_alloc, interval 1, probability 0, space 0, times 1
CPU: 1 PID: 5857 Comm: syz-executor2 Not tainted 4.15.0-rc1-next-20171129+
#55
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_fail_alloc_page mm/page_alloc.c:2943 [inline]
prepare_alloc_pages mm/page_alloc.c:4196 [inline]
__alloc_pages_nodemask+0x338/0xd80 mm/page_alloc.c:4235
__alloc_pages include/linux/gfp.h:456 [inline]
__alloc_pages_node include/linux/gfp.h:469 [inline]
kmem_getpages mm/slab.c:1414 [inline]
cache_grow_begin+0x72/0x570 mm/slab.c:2672
cache_alloc_refill mm/slab.c:3039 [inline]
____cache_alloc mm/slab.c:3121 [inline]
__do_cache_alloc mm/slab.c:3343 [inline]
slab_alloc mm/slab.c:3378 [inline]
kmem_cache_alloc+0x403/0x760 mm/slab.c:3546
getname_flags+0xcb/0x580 fs/namei.c:138
getname+0x19/0x20 fs/namei.c:209
do_sys_open+0x2e7/0x6d0 fs/open.c:1053
SYSC_open fs/open.c:1077 [inline]
SyS_open+0x2d/0x40 fs/open.c:1072
entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x40cd11
RSP: 002b:00007f771dbdd780 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 000000000040cd11
RDX: 0000000000000000 RSI: 0000000072be4c3d RDI: 00007f771dbdd830
RBP: 00000000000005a5 R08: 00007f771dbdd790 R09: 00000000000005a5
R10: 0000000020fd7ff3 R11: 0000000000000293 R12: 00000000006f5818
R13: 0000000000000014 R14: 00007f771dbde6d4 R15: ffffffffffffffff


---
This bug is generated by a dumb bot. It may contain errors.
See https://goo.gl/tpsmEJ for details.
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[Dmitry Vyukov]

On Sun, Dec 3, 2017 at 6:49 PM, syzbot
<bot+7e57fd0c3d95aeefc7...@syzkaller.appspotmail.com>
wrote:

> Hello,
>
> syzkaller hit the following crash on
> d127129e85a020879f334154300ddd3f7ec21c1e
> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
>
> Unfortunately, I don't have any reproducer for this bug yet.

Another perf deadlock that involves splice, so:

#syz dup: possible deadlock in perf_event_ctx_lock_nested

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