============================================
WARNING: possible recursive locking detected
5.16.0-rc2-next-20211125-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.2/18896 is trying to acquire lock:
ffffffff9079b770 (&port_lock_key){-.-.}-{2:2}, at: uart_write+0x12c/0x570 drivers/tty/serial/serial_core.c:577
but task is already holding lock:
ffffffff9079b770 (&port_lock_key){-.-.}-{2:2}, at: serial8250_handle_irq.part.0+0x21/0x3d0 drivers/tty/serial/8250/8250_port.c:1908
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&port_lock_key);
lock(&port_lock_key);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by syz-executor.2/18896:
#0: ffff888084e146d8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline]
#0: ffff888084e146d8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: zap_pte_range mm/memory.c:1323 [inline]
#0: ffff888084e146d8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: zap_pmd_range mm/memory.c:1467 [inline]
#0: ffff888084e146d8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: zap_pud_range mm/memory.c:1496 [inline]
#0: ffff888084e146d8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: zap_p4d_range mm/memory.c:1517 [inline]
#0: ffff888084e146d8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: unmap_page_range+0x86a/0x32e0 mm/memory.c:1538
#1: ffff888019aad8b0 (&i->lock){-.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline]
#1: ffff888019aad8b0 (&i->lock){-.-.}-{2:2}, at: serial8250_interrupt+0x3a/0x200 drivers/tty/serial/8250/8250_core.c:116
#2: ffffffff9079b770 (&port_lock_key){-.-.}-{2:2}, at: serial8250_handle_irq.part.0+0x21/0x3d0 drivers/tty/serial/8250/8250_port.c:1908
#3: ffff88806db5b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1d/0x80 drivers/tty/tty_ldisc.c:273
stack backtrace:
CPU: 1 PID: 18896 Comm: syz-executor.2 Not tainted 5.16.0-rc2-next-20211125-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_deadlock_bug kernel/locking/lockdep.c:2956 [inline]
check_deadlock kernel/locking/lockdep.c:2999 [inline]
validate_chain kernel/locking/lockdep.c:3788 [inline]
__lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5027
lock_acquire kernel/locking/lockdep.c:5637 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
uart_write+0x12c/0x570 drivers/tty/serial/serial_core.c:577
n_hdlc_send_frames+0x24b/0x490 drivers/tty/n_hdlc.c:290
tty_wakeup+0xe1/0x120 drivers/tty/tty_io.c:534
tty_port_default_wakeup+0x26/0x40 drivers/tty/tty_port.c:51
serial8250_tx_chars+0x4f3/0xad0 drivers/tty/serial/8250/8250_port.c:1845
serial8250_handle_irq.part.0+0x328/0x3d0 drivers/tty/serial/8250/8250_port.c:1932
serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1905 [inline]
serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1949
serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126
__handle_irq_event_percpu+0x303/0x8f0 kernel/irq/handle.c:158
handle_irq_event_percpu kernel/irq/handle.c:198 [inline]
handle_irq_event+0x102/0x280 kernel/irq/handle.c:215
handle_edge_irq+0x25f/0xd00 kernel/irq/chip.c:822
generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
handle_irq arch/x86/kernel/irq.c:231 [inline]
__common_interrupt+0x9d/0x210 arch/x86/kernel/irq.c:250
common_interrupt+0xa4/0xc0 arch/x86/kernel/irq.c:240
asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629
RIP: 0010:rcu_read_lock_sched_held+0x45/0x70 kernel/rcu/update.c:125
Code: 00 84 c0 74 41 e8 cb 9b 00 00 84 c0 74 38 be ff ff ff ff 48 c7 c7 60 31 b8 8b e8 96 a8 eb 07 85 c0 75 d3 65 8b 05 4b ae 9f 7e ff ff ff 7f 75 c5 9c 41 5c 49 c1 ec 09 49 83 f4 01 41 83 e4 01
RSP: 0018:ffffc90005b175c0 EFLAGS: 00000246
RAX: 0000000080000002 RBX: 1ffff92000b62ebc RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8d914ad7
R10: fffffbfff1b2295a R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: ffffffff8bb83220 R15: 0000000000000000
trace_lock_acquire include/trace/events/lock.h:13 [inline]
lock_acquire+0x442/0x510 kernel/locking/lockdep.c:5608
rcu_lock_acquire include/linux/rcupdate.h:268 [inline]
rcu_read_lock include/linux/rcupdate.h:694 [inline]
folio_memcg_lock+0x3a/0x6c0 mm/memcontrol.c:2034
page_remove_rmap+0x25/0x1d10 mm/rmap.c:1348
zap_pte_range mm/memory.c:1357 [inline]
zap_pmd_range mm/memory.c:1467 [inline]
zap_pud_range mm/memory.c:1496 [inline]
zap_p4d_range mm/memory.c:1517 [inline]
unmap_page_range+0xe51/0x32e0 mm/memory.c:1538
unmap_single_vma+0x198/0x310 mm/memory.c:1583
unmap_vmas+0x16b/0x2f0 mm/memory.c:1615
exit_mmap+0x1d0/0x630 mm/mmap.c:3176
__mmput+0x122/0x4b0 kernel/fork.c:1115
mmput+0x56/0x60 kernel/fork.c:1136
exit_mm kernel/exit.c:507 [inline]
do_exit+0xb27/0x2c20 kernel/exit.c:819
do_group_exit+0x125/0x310 kernel/exit.c:929
get_signal+0x34c/0x28b0 kernel/signal.c:2859
arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868
handle_signal_work kernel/entry/common.c:148 [inline]
exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f156e404ae9
Code: Unable to access opcode bytes at RIP 0x7f156e404abf.
RSP: 002b:00007f156b97a218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007f156e517f68 RCX: 00007f156e404ae9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f156e517f6c
RBP: 00007f156e517f60 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f156e517f6c
R13: 00007ffc1a46ec5f R14: 00007f156b97a300 R15: 0000000000022000
----------------
Code disassembly (best guess):
0: 00 84 c0 74 41 e8 cb add %al,-0x3417be8c(%rax,%rax,8)
7: 9b fwait
8: 00 00 add %al,(%rax)
a: 84 c0 test %al,%al
c: 74 38 je 0x46
e: be ff ff ff ff mov $0xffffffff,%esi
13: 48 c7 c7 60 31 b8 8b mov $0xffffffff8bb83160,%rdi
1a: e8 96 a8 eb 07 callq 0x7eba8b5
1f: 85 c0 test %eax,%eax
21: 75 d3 jne 0xfffffff6
23: 65 8b 05 4b ae 9f 7e mov %gs:0x7e9fae4b(%rip),%eax # 0x7e9fae75
* 2a: a9 ff ff ff 7f test $0x7fffffff,%eax <-- trapping instruction
2f: 75 c5 jne 0xfffffff6
31: 9c pushfq
32: 41 5c pop %r12
34: 49 c1 ec 09 shr $0x9,%r12
38: 49 83 f4 01 xor $0x1,%r12
3c: 41 83 e4 01 and $0x1,%r12d