sp0: Synchronizing with TNC ------------[ cut here ]------------ ====================================================== WARNING: possible circular locking dependency detected 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0 Not tainted ------------------------------------------------------ syz-executor.3/6219 is trying to acquire lock: ffffffff8dac2860 (console_owner){....}-{0:0}, at: console_lock_spinning_enable kernel/printk/printk.c:1870 [inline] ffffffff8dac2860 (console_owner){....}-{0:0}, at: console_emit_next_record kernel/printk/printk.c:2922 [inline] ffffffff8dac2860 (console_owner){....}-{0:0}, at: console_flush_all+0x4ff/0xd70 kernel/printk/printk.c:2994 but task is already holding lock: ffffffff94d61bd8 (&port_lock_key){-.-.}-{2:2}, at: uart_port_lock_irqsave include/linux/serial_core.h:618 [inline] ffffffff94d61bd8 (&port_lock_key){-.-.}-{2:2}, at: uart_write+0x134/0x3e0 drivers/tty/serial/serial_core.c:624 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&port_lock_key){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 uart_port_lock_irqsave include/linux/serial_core.h:618 [inline] serial8250_console_write+0xaa6/0x1090 drivers/tty/serial/8250/8250_port.c:3352 console_emit_next_record kernel/printk/printk.c:2928 [inline] console_flush_all+0x53f/0xd70 kernel/printk/printk.c:2994 console_unlock+0xae/0x290 kernel/printk/printk.c:3063 vprintk_emit kernel/printk/printk.c:2345 [inline] vprintk_emit+0x11a/0x5a0 kernel/printk/printk.c:2300 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:45 _printk+0xc8/0x100 kernel/printk/printk.c:2370 register_console+0xa88/0x10a0 kernel/printk/printk.c:3596 univ8250_console_init+0x35/0x50 drivers/tty/serial/8250/8250_core.c:719 console_init+0xcc/0x680 kernel/printk/printk.c:3742 start_kernel+0x295/0x4c0 init/main.c:1038 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x148 -> #0 (console_owner){....}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 console_lock_spinning_enable kernel/printk/printk.c:1870 [inline] console_emit_next_record kernel/printk/printk.c:2922 [inline] console_flush_all+0x514/0xd70 kernel/printk/printk.c:2994 console_unlock+0xae/0x290 kernel/printk/printk.c:3063 vprintk_emit kernel/printk/printk.c:2345 [inline] vprintk_emit+0x11a/0x5a0 kernel/printk/printk.c:2300 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:45 _printk+0xc8/0x100 kernel/printk/printk.c:2370 __report_bug lib/bug.c:195 [inline] report_bug+0x4ac/0x580 lib/bug.c:219 handle_bug+0x3d/0x70 arch/x86/kernel/traps.c:239 exc_invalid_op+0x17/0x50 arch/x86/kernel/traps.c:260 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621 uart_write+0x2bf/0x3e0 drivers/tty/serial/serial_core.c:625 tnc_init drivers/net/hamradio/6pack.c:531 [inline] sixpack_open+0x93b/0xb30 drivers/net/hamradio/6pack.c:628 tty_ldisc_open+0x9c/0x120 drivers/tty/tty_ldisc.c:432 tty_set_ldisc+0x318/0x720 drivers/tty/tty_ldisc.c:563 tiocsetd drivers/tty/tty_io.c:2439 [inline] tty_ioctl+0xc2e/0x1650 drivers/tty/tty_io.c:2739 tty_compat_ioctl+0x25c/0x4f0 drivers/tty/tty_io.c:2953 __do_compat_sys_ioctl+0x2c3/0x330 fs/ioctl.c:1007 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&port_lock_key); lock(console_owner); lock(&port_lock_key); lock(console_owner); *** DEADLOCK *** 5 locks held by syz-executor.3/6219: #0: ffff888021f551c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_set_ldisc+0x8b/0x720 drivers/tty/tty_ldisc.c:528 #1: ffff888021f550a0 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:289 [inline] #1: ffff888021f550a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock+0x65/0xb0 drivers/tty/tty_ldisc.c:313 #2: ffffffff94d61bd8 (&port_lock_key){-.-.}-{2:2}, at: uart_port_lock_irqsave include/linux/serial_core.h:618 [inline] #2: ffffffff94d61bd8 (&port_lock_key){-.-.}-{2:2}, at: uart_write+0x134/0x3e0 drivers/tty/serial/serial_core.c:624 #3: ffffffff8dba2ca0 (console_lock){+.+.}-{0:0}, at: vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:45 #4: ffffffff8dba2d10 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:334 [inline] #4: ffffffff8dba2d10 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline] #4: ffffffff8dba2d10 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:286 [inline] #4: ffffffff8dba2d10 (console_srcu){....}-{0:0}, at: console_flush_all+0x12d/0xd70 kernel/printk/printk.c:2986 stack backtrace: CPU: 0 PID: 6219 Comm: syz-executor.3 Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 console_lock_spinning_enable kernel/printk/printk.c:1870 [inline] console_emit_next_record kernel/printk/printk.c:2922 [inline] console_flush_all+0x514/0xd70 kernel/printk/printk.c:2994 console_unlock+0xae/0x290 kernel/printk/printk.c:3063 vprintk_emit kernel/printk/printk.c:2345 [inline] vprintk_emit+0x11a/0x5a0 kernel/printk/printk.c:2300 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:45 _printk+0xc8/0x100 kernel/printk/printk.c:2370 __report_bug lib/bug.c:195 [inline] report_bug+0x4ac/0x580 lib/bug.c:219 handle_bug+0x3d/0x70 arch/x86/kernel/traps.c:239 exc_invalid_op+0x17/0x50 arch/x86/kernel/traps.c:260 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621 RIP: 0010:uart_write+0x2bf/0x3e0 drivers/tty/serial/serial_core.c:625 Code: 6f fc e9 4e ff ff ff e8 0f 70 95 fc 90 0f 0b 90 49 c7 c4 d2 ff ff ff e9 39 ff ff ff e8 fa 6f 95 fc 45 31 ff e8 f2 6f 95 fc 90 <0f> 0b 90 48 85 ed 74 8c e8 e4 6f 95 fc 4c 8d a5 08 01 00 00 4c 89 RSP: 0018:ffffc90006c87b88 EFLAGS: 00010046 RAX: 0000000000040000 RBX: ffff88801dd48be8 RCX: ffffc9002ae03000 RDX: 0000000000040000 RSI: ffffffff84f91fde RDI: ffff88801dd48f48 RBP: ffffffff94d61bc0 R08: 0000000000000001 R09: fffff52000d90f5f R10: 0000000000000003 R11: 0000000000000002 R12: 0000000000000001 R13: 0000000000000001 R14: ffff88804c364f01 R15: 0000000000000246 tnc_init drivers/net/hamradio/6pack.c:531 [inline] sixpack_open+0x93b/0xb30 drivers/net/hamradio/6pack.c:628 tty_ldisc_open+0x9c/0x120 drivers/tty/tty_ldisc.c:432 tty_set_ldisc+0x318/0x720 drivers/tty/tty_ldisc.c:563 tiocsetd drivers/tty/tty_io.c:2439 [inline] tty_ioctl+0xc2e/0x1650 drivers/tty/tty_io.c:2739 tty_compat_ioctl+0x25c/0x4f0 drivers/tty/tty_io.c:2953 __do_compat_sys_ioctl+0x2c3/0x330 fs/ioctl.c:1007 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7275579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f5e675ac EFLAGS: 00000292 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000005423 RDX: 0000000020000040 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 WARNING: CPU: 0 PID: 6219 at drivers/tty/serial/serial_core.c:625 uart_write+0x2bf/0x3e0 drivers/tty/serial/serial_core.c:625 Modules linked in: CPU: 0 PID: 6219 Comm: syz-executor.3 Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:uart_write+0x2bf/0x3e0 drivers/tty/serial/serial_core.c:625 Code: 6f fc e9 4e ff ff ff e8 0f 70 95 fc 90 0f 0b 90 49 c7 c4 d2 ff ff ff e9 39 ff ff ff e8 fa 6f 95 fc 45 31 ff e8 f2 6f 95 fc 90 <0f> 0b 90 48 85 ed 74 8c e8 e4 6f 95 fc 4c 8d a5 08 01 00 00 4c 89 RSP: 0018:ffffc90006c87b88 EFLAGS: 00010046 RAX: 0000000000040000 RBX: ffff88801dd48be8 RCX: ffffc9002ae03000 RDX: 0000000000040000 RSI: ffffffff84f91fde RDI: ffff88801dd48f48 RBP: ffffffff94d61bc0 R08: 0000000000000001 R09: fffff52000d90f5f R10: 0000000000000003 R11: 0000000000000002 R12: 0000000000000001 R13: 0000000000000001 R14: ffff88804c364f01 R15: 0000000000000246 FS: 0000000000000000(0000) GS:ffff88802c000000(0063) knlGS:00000000f5e67b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f73f1fc8 CR3: 000000005af3c000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tnc_init drivers/net/hamradio/6pack.c:531 [inline] sixpack_open+0x93b/0xb30 drivers/net/hamradio/6pack.c:628 tty_ldisc_open+0x9c/0x120 drivers/tty/tty_ldisc.c:432 tty_set_ldisc+0x318/0x720 drivers/tty/tty_ldisc.c:563 tiocsetd drivers/tty/tty_io.c:2439 [inline] tty_ioctl+0xc2e/0x1650 drivers/tty/tty_io.c:2739 tty_compat_ioctl+0x25c/0x4f0 drivers/tty/tty_io.c:2953 __do_compat_sys_ioctl+0x2c3/0x330 fs/ioctl.c:1007 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7275579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f5e675ac EFLAGS: 00000292 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000005423 RDX: 0000000020000040 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi