------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.3.3209/16262 is trying to acquire lock:
ffffffff8e126620 (console_owner){-.-.}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:339 [inline]
ffffffff8e126620 (console_owner){-.-.}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline]
ffffffff8e126620 (console_owner){-.-.}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:292 [inline]
ffffffff8e126620 (console_owner){-.-.}-{0:0}, at: console_flush_all+0x10b/0xcf0 kernel/printk/printk.c:2992
but task is already holding lock:
ffff8880b8c3c258 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x9c/0x130 kernel/sched/core.c:578
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&rq->__lock){-.-.}-{2:2}:
_raw_spin_lock_nested+0x32/0x50 kernel/locking/spinlock.c:378
raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:570
raw_spin_rq_lock kernel/sched/sched.h:1380 [inline]
rq_lock kernel/sched/sched.h:1689 [inline]
task_fork_fair+0x62/0x1f0 kernel/sched/fair.c:12738
sched_cgroup_fork+0x352/0x3e0 kernel/sched/core.c:4829
copy_process+0x21fd/0x3da0 kernel/fork.c:2619
kernel_clone+0x24b/0x8a0 kernel/fork.c:2919
user_mode_thread+0x111/0x180 kernel/fork.c:2997
rest_init+0x27/0x300 init/main.c:675
arch_call_rest_init+0xe/0x10 init/main.c:806
start_kernel+0x461/0x4e0 init/main.c:1051
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
copy_bootdata+0x0/0xd0 arch/x86/kernel/head64.c:536
secondary_startup_64_no_verify+0x179/0x17b
-> #3 (&p->pi_lock){-.-.}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:523 [inline]
try_to_wake_up+0x5b/0x10e0 kernel/sched/core.c:4244
__wake_up_common+0x28e/0x4d0 kernel/sched/wait.c:107
__wake_up_common_lock kernel/sched/wait.c:138 [inline]
__wake_up+0x125/0x1a0 kernel/sched/wait.c:160
tty_port_default_wakeup+0xa2/0xf0 drivers/tty/tty_port.c:69
serial8250_tx_chars+0x6a2/0x8b0 drivers/tty/serial/8250/8250_port.c:1837
serial8250_handle_irq+0x6c3/0x8c0 drivers/tty/serial/8250/8250_port.c:1951
serial8250_default_handle_irq+0xb8/0x1a0 drivers/tty/serial/8250/8250_port.c:1971
serial8250_interrupt+0x9f/0x1c0 drivers/tty/serial/8250/8250_core.c:127
__handle_irq_event_percpu+0x271/0x940 kernel/irq/handle.c:158
handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:210
handle_edge_irq+0x246/0xb20 kernel/irq/chip.c:831
generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
handle_irq arch/x86/kernel/irq.c:240 [inline]
__common_interrupt+0x13b/0x230 arch/x86/kernel/irq.c:259
common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:249
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:678
native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:147
arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:753
default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
cpuidle_idle_call kernel/sched/idle.c:178 [inline]
do_idle+0x334/0x5c0 kernel/sched/idle.c:302
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401
start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323
secondary_startup_64_no_verify+0x179/0x17b
-> #2 (&tty->write_wait){-.-.}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
__wake_up_common_lock kernel/sched/wait.c:137 [inline]
__wake_up+0x10b/0x1a0 kernel/sched/wait.c:160
tty_port_default_wakeup+0xa2/0xf0 drivers/tty/tty_port.c:69
serial8250_tx_chars+0x6a2/0x8b0 drivers/tty/serial/8250/8250_port.c:1837
serial8250_handle_irq+0x6c3/0x8c0 drivers/tty/serial/8250/8250_port.c:1951
serial8250_default_handle_irq+0xb8/0x1a0 drivers/tty/serial/8250/8250_port.c:1971
serial8250_interrupt+0x9f/0x1c0 drivers/tty/serial/8250/8250_core.c:127
__handle_irq_event_percpu+0x271/0x940 kernel/irq/handle.c:158
handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:210
handle_edge_irq+0x246/0xb20 kernel/irq/chip.c:831
generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
handle_irq arch/x86/kernel/irq.c:240 [inline]
__common_interrupt+0x13b/0x230 arch/x86/kernel/irq.c:259
common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:249
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:678
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
uart_write+0x45b/0x5d0 drivers/tty/serial/serial_core.c:634
process_output_block drivers/tty/n_tty.c:580 [inline]
n_tty_write+0xd3d/0x11e0 drivers/tty/n_tty.c:2395
iterate_tty_write drivers/tty/tty_io.c:1019 [inline]
file_tty_write+0x529/0x960 drivers/tty/tty_io.c:1090
call_write_iter include/linux/fs.h:2019 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x474/0x9a0 fs/read_write.c:584
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
-> #1 (&port_lock_key){-.-.}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
serial8250_console_write+0x181/0x18b0 drivers/tty/serial/8250/8250_port.c:3446
console_emit_next_record kernel/printk/printk.c:2944 [inline]
console_flush_all+0x6ad/0xcf0 kernel/printk/printk.c:3000
console_unlock+0xad/0x350 kernel/printk/printk.c:3069
vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
_printk+0xde/0x130 kernel/printk/printk.c:2366
register_console+0xb96/0xf00 kernel/printk/printk.c:3583
univ8250_console_init+0x45/0x50 drivers/tty/serial/8250/8250_core.c:717
console_init+0x17b/0x5d0 kernel/printk/printk.c:3726
start_kernel+0x2c8/0x4e0 init/main.c:987
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
copy_bootdata+0x0/0xd0 arch/x86/kernel/head64.c:536
secondary_startup_64_no_verify+0x179/0x17b
-> #0 (console_owner){-.-.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3162 [inline]
check_prevs_add kernel/locking/lockdep.c:3281 [inline]
validate_chain kernel/locking/lockdep.c:3897 [inline]
__lock_acquire+0x3a07/0x7eb0 kernel/locking/lockdep.c:5171
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5790
console_lock_spinning_enable kernel/printk/printk.c:1871 [inline]
console_emit_next_record kernel/printk/printk.c:2938 [inline]
console_flush_all+0x676/0xcf0 kernel/printk/printk.c:3000
console_unlock+0xad/0x350 kernel/printk/printk.c:3069
vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
_printk+0xde/0x130 kernel/printk/printk.c:2366
__report_bug lib/bug.c:195 [inline]
report_bug+0x34e/0x4f0 lib/bug.c:219
handle_bug+0xcf/0x120 arch/x86/kernel/traps.c:310
exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:345
asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:606
update_rq_clock+0x32e/0x4b0 kernel/sched/core.c:783
pick_next_task kernel/sched/core.c:6200 [inline]
__schedule+0x2ca1/0x4700 kernel/sched/core.c:6684
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6889
preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6913
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1523 [inline]
zap_pmd_range mm/memory.c:1571 [inline]
zap_pud_range mm/memory.c:1600 [inline]
zap_p4d_range mm/memory.c:1621 [inline]
unmap_page_range+0x2577/0x32f0 mm/memory.c:1642
unmap_vmas+0x286/0x3f0 mm/memory.c:1732
exit_mmap+0x238/0xb90 mm/mmap.c:3310
__mmput+0x118/0x3a0 kernel/fork.c:1362
exit_mm+0x23f/0x340 kernel/exit.c:576
do_exit+0x909/0x2530 kernel/exit.c:877
do_group_exit+0x22d/0x2f0 kernel/exit.c:1032
get_signal+0x12a6/0x1390 kernel/signal.c:2927
arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213
__syscall_exit_to_user_mode_work kernel/entry/common.c:294 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:305
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
other info that might help us debug this:
Chain exists of:
console_owner --> &p->pi_lock --> &rq->__lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&rq->__lock);
lock(&p->pi_lock);
lock(&rq->__lock);
lock(console_owner);
*** DEADLOCK ***
5 locks held by syz.3.3209/16262:
#0: ffff888020b94da0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:146 [inline]
#0: ffff888020b94da0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x182/0xb90 mm/mmap.c:3295
#1: ffffffff8e1322e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#1: ffffffff8e1322e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#1: ffffffff8e1322e0 (rcu_read_lock){....}-{1:2}, at: __pte_offset_map+0x2c/0x280 mm/pgtable-generic.c:287
#2: ffff8880b8c3c258 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x9c/0x130 kernel/sched/core.c:578
#3: ffffffff8e126700 (console_lock){+.+.}-{0:0}, at: _printk+0xde/0x130 kernel/printk/printk.c:2366
#4: ffffffff8e00df10 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:339 [inline]
#4: ffffffff8e00df10 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline]
#4: ffffffff8e00df10 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:292 [inline]
#4: ffffffff8e00df10 (console_srcu){....}-{0:0}, at: console_flush_all+0x10b/0xcf0 kernel/printk/printk.c:2992
stack backtrace:
CPU: 0 PID: 16262 Comm: syz.3.3209 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2215
check_prev_add kernel/locking/lockdep.c:3162 [inline]
check_prevs_add kernel/locking/lockdep.c:3281 [inline]
validate_chain kernel/locking/lockdep.c:3897 [inline]
__lock_acquire+0x3a07/0x7eb0 kernel/locking/lockdep.c:5171
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5790
console_lock_spinning_enable kernel/printk/printk.c:1871 [inline]
console_emit_next_record kernel/printk/printk.c:2938 [inline]
console_flush_all+0x676/0xcf0 kernel/printk/printk.c:3000
console_unlock+0xad/0x350 kernel/printk/printk.c:3069
vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
_printk+0xde/0x130 kernel/printk/printk.c:2366
__report_bug lib/bug.c:195 [inline]
report_bug+0x34e/0x4f0 lib/bug.c:219
handle_bug+0xcf/0x120 arch/x86/kernel/traps.c:310
exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:345
asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:606
RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1371 [inline]
RIP: 0010:update_rq_clock+0x32e/0x4b0 kernel/sched/core.c:767
Code: 00 00 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 b4 96 83 00 48 01 2b 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 <0f> 0b e9 62 fd ff ff 48 89 df 48 83 c4 08 5b 41 5c 41 5d 41 5e 41
RSP: 0018:ffffc900042c7120 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff8880b8d3c240 RCX: 4c47a1b8d4b2c100
RDX: 0000000000000003 RSI: ffffffff8aeae2c0 RDI: ffffffff8b3c50e0
RBP: ffffc900042c7370 R08: ffff888022ee9027 R09: 0000000000000001
R10: ffff888022ee9018 R11: ffffed10045dd205 R12: ffffffff8ccbca38
R13: dffffc0000000000 R14: ffff8880b8d3cf88 R15: ffff8880b8d3c240
pick_next_task kernel/sched/core.c:6200 [inline]
__schedule+0x2ca1/0x4700 kernel/sched/core.c:6684
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6889
preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6913
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1523 [inline]
zap_pmd_range mm/memory.c:1571 [inline]
zap_pud_range mm/memory.c:1600 [inline]
zap_p4d_range mm/memory.c:1621 [inline]
unmap_page_range+0x2577/0x32f0 mm/memory.c:1642
unmap_vmas+0x286/0x3f0 mm/memory.c:1732
exit_mmap+0x238/0xb90 mm/mmap.c:3310
__mmput+0x118/0x3a0 kernel/fork.c:1362
exit_mm+0x23f/0x340 kernel/exit.c:576
do_exit+0x909/0x2530 kernel/exit.c:877
do_group_exit+0x22d/0x2f0 kernel/exit.c:1032
get_signal+0x12a6/0x1390 kernel/signal.c:2927
arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213
__syscall_exit_to_user_mode_work kernel/entry/common.c:294 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:305
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa61c19f559
Code: Unable to access opcode bytes at 0x7fa61c19f52f.
RSP: 002b:00007fa61a3d50e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fa61c426188 RCX: 00007fa61c19f559
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa61c426188
RBP: 00007fa61c426180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa61c426218 R14: 00007ffc9e9c66f0 R15: 00007ffc9e9c67d8
WARNING: CPU: 0 PID: 16262 at kernel/sched/sched.h:1371 update_rq_clock+0x32e/0x4b0 kernel/sched/core.c:783
Modules linked in:
CPU: 0 PID: 16262 Comm: syz.3.3209 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1371 [inline]
RIP: 0010:update_rq_clock+0x32e/0x4b0 kernel/sched/core.c:767
Code: 00 00 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 b4 96 83 00 48 01 2b 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 <0f> 0b e9 62 fd ff ff 48 89 df 48 83 c4 08 5b 41 5c 41 5d 41 5e 41
RSP: 0018:ffffc900042c7120 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff8880b8d3c240 RCX: 4c47a1b8d4b2c100
RDX: 0000000000000003 RSI: ffffffff8aeae2c0 RDI: ffffffff8b3c50e0
RBP: ffffc900042c7370 R08: ffff888022ee9027 R09: 0000000000000001
R10: ffff888022ee9018 R11: ffffed10045dd205 R12: ffffffff8ccbca38
R13: dffffc0000000000 R14: ffff8880b8d3cf88 R15: ffff8880b8d3c240
FS: 0000000000000000(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f659bb1d943 CR3: 000000007cfda000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000001800
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
pick_next_task kernel/sched/core.c:6200 [inline]
__schedule+0x2ca1/0x4700 kernel/sched/core.c:6684
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6889
preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6913
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1523 [inline]
zap_pmd_range mm/memory.c:1571 [inline]
zap_pud_range mm/memory.c:1600 [inline]
zap_p4d_range mm/memory.c:1621 [inline]
unmap_page_range+0x2577/0x32f0 mm/memory.c:1642
unmap_vmas+0x286/0x3f0 mm/memory.c:1732
exit_mmap+0x238/0xb90 mm/mmap.c:3310
__mmput+0x118/0x3a0 kernel/fork.c:1362
exit_mm+0x23f/0x340 kernel/exit.c:576
do_exit+0x909/0x2530 kernel/exit.c:877
do_group_exit+0x22d/0x2f0 kernel/exit.c:1032
get_signal+0x12a6/0x1390 kernel/signal.c:2927
arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213
__syscall_exit_to_user_mode_work kernel/entry/common.c:294 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:305
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa61c19f559
Code: Unable to access opcode bytes at 0x7fa61c19f52f.
RSP: 002b:00007fa61a3d50e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fa61c426188 RCX: 00007fa61c19f559
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa61c426188
RBP: 00007fa61c426180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa61c426218 R14: 00007ffc9e9c66f0 R15: 00007ffc9e9c67d8