BUG: unable to handle kernel paging request in hrtimer_update_next_event

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syzbot

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Jun 27, 2022, 9:18:33 AM6/27/22
to syzkaller-upst...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: 0966d385830d riscv: Fix auipc+jalr relocation range checks
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes
console output: https://syzkaller.appspot.com/x/log.txt?x=15ba6560080000
kernel config: https://syzkaller.appspot.com/x/.config?x=6295d67591064921
dashboard link: https://syzkaller.appspot.com/bug?extid=56ca986b9fd739fa779a
compiler: riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: riscv64
CC: [linux-...@vger.kernel.org tg...@linutronix.de]

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+56ca98...@syzkaller.appspotmail.com

Unable to handle kernel paging request at virtual address ffffffff8011115c

======================================================
WARNING: possible circular locking dependency detected
5.17.0-rc1-syzkaller-00002-g0966d385830d #0 Not tainted
------------------------------------------------------
sshd/2022 is trying to acquire lock:
ffffffff84a888e0 (console_owner){-...}-{0:0}, at: console_unlock+0x2b2/0x97a kernel/printk/printk.c:2707

but task is already holding lock:
ffffaf805a9e7418 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1689 [inline]
ffffaf805a9e7418 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x262/0xa16 kernel/time/hrtimer.c:1749

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #6 (hrtimer_bases.lock){-.-.}-{2:2}:
lock_acquire.part.0+0x1d0/0x424 kernel/locking/lockdep.c:5639
lock_acquire+0x54/0x6a kernel/locking/lockdep.c:5612
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3e/0x62 kernel/locking/spinlock.c:162
lock_hrtimer_base kernel/time/hrtimer.c:173 [inline]
hrtimer_start_range_ns+0x9e/0x6dc kernel/time/hrtimer.c:1296
hrtimer_start_expires include/linux/hrtimer.h:432 [inline]
do_start_rt_bandwidth kernel/sched/rt.c:69 [inline]
start_rt_bandwidth kernel/sched/rt.c:80 [inline]
inc_rt_group kernel/sched/rt.c:1208 [inline]
inc_rt_tasks kernel/sched/rt.c:1252 [inline]
__enqueue_rt_entity kernel/sched/rt.c:1428 [inline]
enqueue_rt_entity kernel/sched/rt.c:1474 [inline]
enqueue_task_rt+0x520/0x568 kernel/sched/rt.c:1509
enqueue_task+0x66/0x136 kernel/sched/core.c:2010
__sched_setscheduler.constprop.0+0x704/0xdd4 kernel/sched/core.c:7475
_sched_setscheduler kernel/sched/core.c:7521 [inline]
sched_setscheduler_nocheck kernel/sched/core.c:7568 [inline]
sched_set_fifo+0xc8/0x108 kernel/sched/core.c:7592
drm_vblank_worker_init+0xea/0x10c drivers/gpu/drm/drm_vblank_work.c:263
drm_vblank_init+0xec/0x24e drivers/gpu/drm/drm_vblank.c:551
vkms_create drivers/gpu/drm/vkms/vkms_drv.c:194 [inline]
vkms_init+0x272/0x45c drivers/gpu/drm/vkms/vkms_drv.c:233
do_one_initcall+0x13a/0x7ea init/main.c:1300
do_initcall_level init/main.c:1373 [inline]
do_initcalls init/main.c:1389 [inline]
do_basic_setup init/main.c:1408 [inline]
kernel_init_freeable+0x510/0x5b4 init/main.c:1613
kernel_init+0x28/0x21c init/main.c:1502
ret_from_exception+0x0/0x10

-> #5 (&rt_b->rt_runtime_lock){-...}-{2:2}:
lock_acquire.part.0+0x1d0/0x424 kernel/locking/lockdep.c:5639
lock_acquire+0x54/0x6a kernel/locking/lockdep.c:5612
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x32/0x48 kernel/locking/spinlock.c:154
__enable_runtime kernel/sched/rt.c:840 [inline]
rq_online_rt+0x78/0x1b8 kernel/sched/rt.c:2431
set_rq_online.part.0+0xaa/0xc2 kernel/sched/core.c:8965
set_rq_online kernel/sched/core.c:9075 [inline]
sched_cpu_activate+0x1c0/0x250 kernel/sched/core.c:9070
cpuhp_invoke_callback+0x282/0x504 kernel/cpu.c:191
cpuhp_thread_fun+0x2f6/0x4b0 kernel/cpu.c:791
smpboot_thread_fn+0x448/0x6cc kernel/smpboot.c:164
kthread+0x19e/0x1fa kernel/kthread.c:377
ret_from_exception+0x0/0x10

-> #4 (&rq->__lock){-.-.}-{2:2}:
lock_acquire.part.0+0x1d0/0x424 kernel/locking/lockdep.c:5639
lock_acquire+0x54/0x6a kernel/locking/lockdep.c:5612
_raw_spin_lock_nested+0x36/0x4e kernel/locking/spinlock.c:378
raw_spin_rq_lock_nested+0x22/0x34 kernel/sched/core.c:489
raw_spin_rq_lock kernel/sched/sched.h:1318 [inline]
rq_lock kernel/sched/sched.h:1616 [inline]
task_fork_fair+0xa8/0x218 kernel/sched/fair.c:11146
sched_post_fork+0x16e/0x196 kernel/sched/core.c:4462
copy_process+0x3378/0x3c34 kernel/fork.c:2379
kernel_clone+0xee/0x920 kernel/fork.c:2555
kernel_thread+0xf8/0x130 kernel/fork.c:2607
rest_init+0x34/0x3f2 init/main.c:690
arch_call_rest_init+0x18/0x20 init/main.c:881
start_kernel+0x66a/0x698 init/main.c:1138

-> #3 (&p->pi_lock){-.-.}-{2:2}:
lock_acquire.part.0+0x1d0/0x424 kernel/locking/lockdep.c:5639
lock_acquire+0x54/0x6a kernel/locking/lockdep.c:5612
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3e/0x62 kernel/locking/spinlock.c:162
try_to_wake_up+0xa4/0x748 kernel/sched/core.c:4017
default_wake_function+0x28/0x36 kernel/sched/core.c:6723
woken_wake_function+0x38/0x48 kernel/sched/wait.c:481
__wake_up_common+0xb6/0x236 kernel/sched/wait.c:108
__wake_up_common_lock+0xd6/0x136 kernel/sched/wait.c:138
__wake_up+0x10/0x18 kernel/sched/wait.c:157
tty_wakeup+0x58/0xbe drivers/tty/tty_io.c:534
tty_port_default_wakeup+0x2c/0x44 drivers/tty/tty_port.c:51
tty_port_tty_wakeup+0x3a/0x46 drivers/tty/tty_port.c:413
uart_write_wakeup+0x34/0x48 drivers/tty/serial/serial_core.c:106
serial8250_tx_chars+0x322/0x592 drivers/tty/serial/8250/8250_port.c:1845
serial8250_handle_irq.part.0+0x284/0x286 drivers/tty/serial/8250/8250_port.c:1932
serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1905 [inline]
serial8250_default_handle_irq+0xac/0x142 drivers/tty/serial/8250/8250_port.c:1949
serial8250_interrupt+0xbe/0x1a6 drivers/tty/serial/8250/8250_core.c:126
__handle_irq_event_percpu+0x16e/0x6ec kernel/irq/handle.c:158
handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
handle_irq_event+0x6a/0xfa kernel/irq/handle.c:210
handle_fasteoi_irq+0x1c0/0x4d6 kernel/irq/chip.c:715
generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
handle_irq_desc kernel/irq/irqdesc.c:646 [inline]
generic_handle_domain_irq+0x7c/0x9c kernel/irq/irqdesc.c:680
plic_handle_irq+0x122/0x242 drivers/irqchip/irq-sifive-plic.c:242
generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
handle_irq_desc kernel/irq/irqdesc.c:646 [inline]
generic_handle_domain_irq+0x7c/0x9c kernel/irq/irqdesc.c:680
riscv_intc_irq+0x7e/0xc8 drivers/irqchip/irq-riscv-intc.c:40
generic_handle_arch_irq+0x36/0x54 kernel/irq/handle.c:238
ret_from_exception+0x0/0x10
rcu_gp_cleanup+0x182/0xa90 kernel/rcu/tree.c:2036

-> #2 (&tty->write_wait){-.-.}-{2:2}:
lock_acquire.part.0+0x1d0/0x424 kernel/locking/lockdep.c:5639
lock_acquire+0x54/0x6a kernel/locking/lockdep.c:5612
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3e/0x62 kernel/locking/spinlock.c:162
__wake_up_common_lock+0xc4/0x136 kernel/sched/wait.c:137
__wake_up+0x10/0x18 kernel/sched/wait.c:157
tty_wakeup+0x58/0xbe drivers/tty/tty_io.c:534
tty_port_default_wakeup+0x2c/0x44 drivers/tty/tty_port.c:51
tty_port_tty_wakeup+0x3a/0x46 drivers/tty/tty_port.c:413
uart_write_wakeup+0x34/0x48 drivers/tty/serial/serial_core.c:106
serial8250_tx_chars+0x322/0x592 drivers/tty/serial/8250/8250_port.c:1845
serial8250_handle_irq.part.0+0x284/0x286 drivers/tty/serial/8250/8250_port.c:1932
serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1905 [inline]
serial8250_default_handle_irq+0xac/0x142 drivers/tty/serial/8250/8250_port.c:1949
serial8250_interrupt+0xbe/0x1a6 drivers/tty/serial/8250/8250_core.c:126
__handle_irq_event_percpu+0x16e/0x6ec kernel/irq/handle.c:158
handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
handle_irq_event+0x6a/0xfa kernel/irq/handle.c:210
handle_fasteoi_irq+0x1c0/0x4d6 kernel/irq/chip.c:715
generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
handle_irq_desc kernel/irq/irqdesc.c:646 [inline]
generic_handle_domain_irq+0x7c/0x9c kernel/irq/irqdesc.c:680
plic_handle_irq+0x122/0x242 drivers/irqchip/irq-sifive-plic.c:242
generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
handle_irq_desc kernel/irq/irqdesc.c:646 [inline]
generic_handle_domain_irq+0x7c/0x9c kernel/irq/irqdesc.c:680
riscv_intc_irq+0x7e/0xc8 drivers/irqchip/irq-riscv-intc.c:40
generic_handle_arch_irq+0x36/0x54 kernel/irq/handle.c:238
ret_from_exception+0x0/0x10
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
_raw_spin_unlock_irqrestore+0x68/0x98 kernel/locking/spinlock.c:194

-> #1 (&port_lock_key){-.-.}-{2:2}:
lock_acquire.part.0+0x1d0/0x424 kernel/locking/lockdep.c:5639
lock_acquire+0x54/0x6a kernel/locking/lockdep.c:5612
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3e/0x62 kernel/locking/spinlock.c:162
serial8250_console_write+0x848/0x8e6 drivers/tty/serial/8250/8250_port.c:3387
univ8250_console_write+0x46/0x54 drivers/tty/serial/8250/8250_core.c:575
call_console_drivers kernel/printk/printk.c:1929 [inline]
console_unlock+0x666/0x97a kernel/printk/printk.c:2711
register_console+0x250/0x534 kernel/printk/printk.c:3054
uart_configure_port drivers/tty/serial/serial_core.c:2402 [inline]
uart_add_one_port+0xbf2/0xc14 drivers/tty/serial/serial_core.c:2917
serial8250_register_8250_port+0x8ce/0xc6e drivers/tty/serial/8250/8250_core.c:1082
of_platform_serial_probe+0x7ae/0xa9c drivers/tty/serial/8250/8250_of.c:232
platform_probe+0xc8/0x172 drivers/base/platform.c:1416
call_driver_probe drivers/base/dd.c:517 [inline]
really_probe+0x1a6/0x89e drivers/base/dd.c:596
__driver_probe_device+0x24a/0x2d4 drivers/base/dd.c:752
driver_probe_device+0x60/0x1a4 drivers/base/dd.c:782
__driver_attach+0x178/0x33e drivers/base/dd.c:1141
bus_for_each_dev+0x122/0x194 drivers/base/bus.c:301
driver_attach+0x32/0x3c drivers/base/dd.c:1158
bus_add_driver+0x2c6/0x41a drivers/base/bus.c:618
driver_register+0x144/0x286 drivers/base/driver.c:171
__platform_driver_register+0x46/0x52 drivers/base/platform.c:863
of_platform_serial_driver_init+0x22/0x2a drivers/tty/serial/8250/8250_of.c:341
do_one_initcall+0x13a/0x7ea init/main.c:1300
do_initcall_level init/main.c:1373 [inline]
do_initcalls init/main.c:1389 [inline]
do_basic_setup init/main.c:1408 [inline]
kernel_init_freeable+0x510/0x5b4 init/main.c:1613
kernel_init+0x28/0x21c init/main.c:1502
ret_from_exception+0x0/0x10

-> #0 (console_owner){-...}-{0:0}:
check_noncircular+0x1de/0x1fe kernel/locking/lockdep.c:2143
check_prev_add kernel/locking/lockdep.c:3063 [inline]
check_prevs_add kernel/locking/lockdep.c:3186 [inline]
validate_chain kernel/locking/lockdep.c:3801 [inline]
__lock_acquire+0x19a4/0x333e kernel/locking/lockdep.c:5027
lock_acquire.part.0+0x1d0/0x424 kernel/locking/lockdep.c:5639
lock_acquire+0x54/0x6a kernel/locking/lockdep.c:5612
console_lock_spinning_enable kernel/printk/printk.c:1781 [inline]
console_unlock+0x304/0x97a kernel/printk/printk.c:2708
vprintk_emit+0xd2/0x416 kernel/printk/printk.c:2245
vprintk_default+0x22/0x2e kernel/printk/printk.c:2256
vprintk+0x108/0x13e kernel/printk/printk_safe.c:50
_printk+0xa0/0xc8 kernel/printk/printk.c:2266
die_kernel_fault+0x3a/0x60 arch/riscv/mm/fault.c:29
no_context arch/riscv/mm/fault.c:58 [inline]
no_context arch/riscv/mm/fault.c:37 [inline]
mm_fault_error arch/riscv/mm/fault.c:77 [inline]
do_page_fault+0x5b2/0xa3c arch/riscv/mm/fault.c:348
ret_from_exception+0x0/0x10
__hrtimer_get_next_event kernel/time/hrtimer.c:577 [inline]
hrtimer_update_next_event+0x9e/0x12c kernel/time/hrtimer.c:604

other info that might help us debug this:

Chain exists of:
console_owner --> &rt_b->rt_runtime_lock --> hrtimer_bases.lock

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(hrtimer_bases.lock);
lock(&rt_b->rt_runtime_lock);
lock(hrtimer_bases.lock);
lock(console_owner);

*** DEADLOCK ***

2 locks held by sshd/2022:
#0: ffffaf805a9e7418 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1689 [inline]
#0: ffffaf805a9e7418 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x262/0xa16 kernel/time/hrtimer.c:1749
#1: ffffffff84a88600 (console_lock){+.+.}-{0:0}, at: vprintk_default+0x22/0x2e kernel/printk/printk.c:2256

stack backtrace:
CPU: 1 PID: 2022 Comm: sshd Not tainted 5.17.0-rc1-syzkaller-00002-g0966d385830d #0
Hardware name: riscv-virtio,qemu (DT)
Call Trace:
[<ffffffff8000a228>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:113
[<ffffffff831668cc>] show_stack+0x34/0x40 arch/riscv/kernel/stacktrace.c:119
[<ffffffff831756ba>] __dump_stack lib/dump_stack.c:88 [inline]
[<ffffffff831756ba>] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:106
[<ffffffff83175742>] dump_stack+0x1c/0x24 lib/dump_stack.c:113
[<ffffffff8010f7b8>] print_circular_bug+0x34e/0x3d8 kernel/locking/lockdep.c:2021
[<ffffffff8010fa20>] check_noncircular+0x1de/0x1fe kernel/locking/lockdep.c:2143
[<ffffffff80113c26>] check_prev_add kernel/locking/lockdep.c:3063 [inline]
[<ffffffff80113c26>] check_prevs_add kernel/locking/lockdep.c:3186 [inline]
[<ffffffff80113c26>] validate_chain kernel/locking/lockdep.c:3801 [inline]
[<ffffffff80113c26>] __lock_acquire+0x19a4/0x333e kernel/locking/lockdep.c:5027
[<ffffffff80116582>] lock_acquire.part.0+0x1d0/0x424 kernel/locking/lockdep.c:5639
[<ffffffff8011682a>] lock_acquire+0x54/0x6a kernel/locking/lockdep.c:5612
[<ffffffff8011ee1c>] console_lock_spinning_enable kernel/printk/printk.c:1781 [inline]
[<ffffffff8011ee1c>] console_unlock+0x304/0x97a kernel/printk/printk.c:2708
[<ffffffff8012183e>] vprintk_emit+0xd2/0x416 kernel/printk/printk.c:2245
[<ffffffff80121ba4>] vprintk_default+0x22/0x2e kernel/printk/printk.c:2256
[<ffffffff8012254a>] vprintk+0x108/0x13e kernel/printk/printk_safe.c:50
[<ffffffff83169c5c>] _printk+0xa0/0xc8 kernel/printk/printk.c:2266
[<ffffffff80011232>] die_kernel_fault+0x3a/0x60 arch/riscv/mm/fault.c:29
[<ffffffff80011b38>] no_context arch/riscv/mm/fault.c:58 [inline]
[<ffffffff80011b38>] no_context arch/riscv/mm/fault.c:37 [inline]
[<ffffffff80011b38>] mm_fault_error arch/riscv/mm/fault.c:77 [inline]
[<ffffffff80011b38>] do_page_fault+0x5b2/0xa3c arch/riscv/mm/fault.c:348
[<ffffffff80005724>] ret_from_exception+0x0/0x10
[<ffffffff8016c636>] __hrtimer_get_next_event kernel/time/hrtimer.c:577 [inline]
[<ffffffff8016c636>] hrtimer_update_next_event+0x9e/0x12c kernel/time/hrtimer.c:604
Oops [#1]
Modules linked in:
CPU: 1 PID: 2022 Comm: sshd Not tainted 5.17.0-rc1-syzkaller-00002-g0966d385830d #0
Hardware name: riscv-virtio,qemu (DT)
epc : __hrtimer_get_next_event kernel/time/hrtimer.c:577 [inline]
epc : hrtimer_update_next_event+0xaa/0x12c kernel/time/hrtimer.c:604
ra : __hrtimer_get_next_event kernel/time/hrtimer.c:577 [inline]
ra : hrtimer_update_next_event+0x9e/0x12c kernel/time/hrtimer.c:604
epc : ffffffff8016c642 ra : ffffffff8016c636 sp : ffffaf800cb936b0
gp : ffffffff85863ac0 tp : ffffaf800cf5c8c0 t0 : 0000000000046000
t1 : 3bc8d578b96e3e00 t2 : ffffffff83604ca0 s0 : ffffaf800cb936f0
s1 : ffffffff801110e4 a0 : 0000000000000000 a1 : 0000000000000000
a2 : 0000000000000050 a3 : 7fffffffffffffff a4 : 0000000000000000
a5 : ffffffff8011115c a6 : 0000000000f00000 a7 : ffffffff80b09d26
s2 : 0000000000000000 s3 : ffffffff80111128 s4 : 000000007bb67b56
s5 : ffffffff8011115c s6 : ffffffffffffffff s7 : ffffffff801110e4
s8 : ffffaf800cb93860 s9 : ffffaf805a9e7460 s10: ffffaf805a9e7768
s11: ffffaf805a9e7448 t3 : fffffffff3f3f300 t4 : ffffffff80112282
t5 : 1ffff5f001972638 t6 : 0000000000040000
status: 0000000000000100 badaddr: ffffffff8011115c cause: 000000000000000f
[<ffffffff8016f4ae>] hrtimer_interrupt+0x1da/0x3ea kernel/time/hrtimer.c:1814
[<ffffffff823375da>] riscv_timer_interrupt+0x5c/0x6a drivers/clocksource/timer-riscv.c:97


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unread,
Sep 21, 2022, 9:03:33 AM9/21/22
to syzkaller-upst...@googlegroups.com
Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.
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