Messages in this thread | | | From | Dmitry Vyukov <> | Date | Fri, 8 Jun 2018 09:50:11 +0200 | Subject | Re: possible deadlock in vprintk_emit |
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On Fri, Jun 8, 2018 at 9:38 AM, syzbot <syzbot+831ee52a258e90882b4d@syzkaller.appspotmail.com> wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 1c8c5a9d38f6 Merge git://git.kernel.org/pub/scm/linux/kern.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=131d4ddf800000 > kernel config: https://syzkaller.appspot.com/x/.config?x=4f1acdf888c9d4e9 > dashboard link: https://syzkaller.appspot.com/bug?extid=831ee52a258e90882b4d > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+831ee52a258e90882b4d@syzkaller.appspotmail.com
This is the same as that one, right?
#syz dup: possible deadlock in console_unlock
https://syzkaller.appspot.com/bug?id=39ea6caa479af471183997376dc7e90bc7d64a6a
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000016 > R13: 00000000004be500 R14: 00000000004ccad8 R15: 0000000000000000 > CPU: 0 PID: 19202 Comm: syz-executor2 Not tainted 4.17.0+ #89 > > ====================================================== > WARNING: possible circular locking dependency detected > 4.17.0+ #89 Not tainted > ------------------------------------------------------ > syz-executor6/19187 is trying to acquire lock: > 000000006e810651 (console_owner){-.-.}, at: console_trylock_spinning > kernel/printk/printk.c:1651 [inline] > 000000006e810651 (console_owner){-.-.}, at: vprintk_emit+0x826/0xde0 > kernel/printk/printk.c:1906 > > but task is already holding lock: > 000000004ec3be2c (&(&port->lock)->rlock){-.-.}, at: pty_write+0xf9/0x1f0 > drivers/tty/pty.c:119 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #2 (&(&port->lock)->rlock){-.-.}: > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 > tty_port_tty_get+0x20/0x80 drivers/tty/tty_port.c:288 > tty_port_default_wakeup+0x15/0x40 drivers/tty/tty_port.c:47 > tty_port_tty_wakeup+0x5d/0x70 drivers/tty/tty_port.c:390 > uart_write_wakeup+0x44/0x60 drivers/tty/serial/serial_core.c:103 > serial8250_tx_chars+0x4be/0xb60 > drivers/tty/serial/8250/8250_port.c:1808 > serial8250_handle_irq.part.25+0x1ee/0x280 > drivers/tty/serial/8250/8250_port.c:1881 > serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1867 > [inline] > serial8250_default_handle_irq+0xc8/0x150 > drivers/tty/serial/8250/8250_port.c:1897 > serial8250_interrupt+0xfa/0x1d0 > drivers/tty/serial/8250/8250_core.c:125 > __handle_irq_event_percpu+0x1c0/0xad0 kernel/irq/handle.c:149 > handle_irq_event_percpu+0x98/0x1c0 kernel/irq/handle.c:189 > handle_irq_event+0xa7/0x135 kernel/irq/handle.c:206 > handle_edge_irq+0x20f/0x870 kernel/irq/chip.c:791 > generic_handle_irq_desc include/linux/irqdesc.h:159 [inline] > handle_irq+0x18c/0x2e7 arch/x86/kernel/irq_64.c:77 > do_IRQ+0x78/0x190 arch/x86/kernel/irq.c:245 > ret_from_intr+0x0/0x1e > native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 > arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] > default_idle+0xc2/0x440 arch/x86/kernel/process.c:500 > arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:491 > default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 > cpuidle_idle_call kernel/sched/idle.c:153 [inline] > do_idle+0x395/0x560 kernel/sched/idle.c:262 > cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:368 > start_secondary+0x42b/0x5c0 arch/x86/kernel/smpboot.c:265 > secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242 > > -> #1 (&port_lock_key){-.-.}: > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 > serial8250_console_write+0x8d5/0xb00 > drivers/tty/serial/8250/8250_port.c:3230 > univ8250_console_write+0x5f/0x70 > drivers/tty/serial/8250/8250_core.c:590 > call_console_drivers kernel/printk/printk.c:1718 [inline] > console_unlock+0xa9d/0x10a0 kernel/printk/printk.c:2389 > vprintk_emit+0x6b2/0xde0 kernel/printk/printk.c:1907 > vprintk_default+0x28/0x30 kernel/printk/printk.c:1948 > vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:382 > printk+0x9e/0xba kernel/printk/printk.c:1981 > register_console+0x7e7/0xc00 kernel/printk/printk.c:2704 > univ8250_console_init+0x3f/0x4b > drivers/tty/serial/8250/8250_core.c:685 > console_init+0x6d9/0xa38 kernel/printk/printk.c:2788 > start_kernel+0x608/0x92d init/main.c:661 > x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:452 > x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:433 > secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242 > > -> #0 (console_owner){-.-.}: > lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3924 > console_trylock_spinning kernel/printk/printk.c:1672 [inline] > vprintk_emit+0x884/0xde0 kernel/printk/printk.c:1906 > vprintk_default+0x28/0x30 kernel/printk/printk.c:1948 > vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:382 > printk+0x9e/0xba kernel/printk/printk.c:1981 > fail_dump lib/fault-inject.c:44 [inline] > should_fail+0x97a/0xbcd lib/fault-inject.c:149 > __should_failslab+0x124/0x180 mm/failslab.c:32 > should_failslab+0x9/0x14 mm/slab_common.c:1522 > slab_pre_alloc_hook mm/slab.h:423 [inline] > slab_alloc mm/slab.c:3378 [inline] > __do_kmalloc mm/slab.c:3716 [inline] > __kmalloc+0x63/0x760 mm/slab.c:3727 > kmalloc include/linux/slab.h:518 [inline] > tty_buffer_alloc drivers/tty/tty_buffer.c:170 [inline] > __tty_buffer_request_room+0x2d2/0x7f0 drivers/tty/tty_buffer.c:268 > tty_insert_flip_string_fixed_flag+0x8d/0x1f0 > drivers/tty/tty_buffer.c:313 > tty_insert_flip_string include/linux/tty_flip.h:37 [inline] > pty_write+0x12c/0x1f0 drivers/tty/pty.c:121 > tty_put_char+0x129/0x150 drivers/tty/tty_io.c:2865 > __process_echoes+0x4d9/0x8d0 drivers/tty/n_tty.c:703 > process_echoes+0xfc/0x170 drivers/tty/n_tty.c:781 > n_tty_set_termios+0xb56/0xe80 drivers/tty/n_tty.c:1837 > tty_set_termios+0x7a0/0xac0 drivers/tty/tty_ioctl.c:341 > set_termios+0x41e/0x7d0 drivers/tty/tty_ioctl.c:414 > tty_mode_ioctl+0x535/0xb50 drivers/tty/tty_ioctl.c:747 > n_tty_ioctl_helper+0x54/0x3b0 drivers/tty/tty_ioctl.c:940 > n_tty_ioctl+0x54/0x320 drivers/tty/n_tty.c:2441 > tty_ioctl+0x5e1/0x1870 drivers/tty/tty_io.c:2655 > vfs_ioctl fs/ioctl.c:46 [inline] > file_ioctl fs/ioctl.c:500 [inline] > do_vfs_ioctl+0x1cf/0x16f0 fs/ioctl.c:684 > ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 > __do_sys_ioctl fs/ioctl.c:708 [inline] > __se_sys_ioctl fs/ioctl.c:706 [inline] > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 > do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > other info that might help us debug this: > > Chain exists of: > console_owner --> &port_lock_key --> &(&port->lock)->rlock > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(&(&port->lock)->rlock); > lock(&port_lock_key); > lock(&(&port->lock)->rlock); > lock(console_owner); > > *** DEADLOCK *** > > 5 locks held by syz-executor6/19187: > #0: 000000007080a3ba (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 > drivers/tty/tty_ldsem.c:365 > #1: 000000006fe00659 (&o_tty->termios_rwsem/1){++++}, at: > tty_set_termios+0xfd/0xac0 drivers/tty/tty_ioctl.c:328 > #2: 000000007080a3ba (&tty->ldisc_sem){++++}, at: tty_ldisc_ref+0x22/0x90 > drivers/tty/tty_ldisc.c:284 > #3: 00000000f8d1ab16 (&ldata->output_lock){+.+.}, at: > process_echoes+0xb6/0x170 drivers/tty/n_tty.c:779 > #4: 000000004ec3be2c (&(&port->lock)->rlock){-.-.}, at: > pty_write+0xf9/0x1f0 drivers/tty/pty.c:119 > > stack backtrace: > CPU: 1 PID: 19187 Comm: syz-executor6 Not tainted 4.17.0+ #89 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x1b9/0x294 lib/dump_stack.c:113 > print_circular_bug.isra.36.cold.56+0x1bd/0x27d > kernel/locking/lockdep.c:1227 > check_prev_add kernel/locking/lockdep.c:1867 [inline] > check_prevs_add kernel/locking/lockdep.c:1980 [inline] > validate_chain kernel/locking/lockdep.c:2421 [inline] > __lock_acquire+0x343e/0x5140 kernel/locking/lockdep.c:3435 > lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3924 > console_trylock_spinning kernel/printk/printk.c:1672 [inline] > vprintk_emit+0x884/0xde0 kernel/printk/printk.c:1906 > vprintk_default+0x28/0x30 kernel/printk/printk.c:1948 > vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:382 > printk+0x9e/0xba kernel/printk/printk.c:1981 > fail_dump lib/fault-inject.c:44 [inline] > should_fail+0x97a/0xbcd lib/fault-inject.c:149 > __should_failslab+0x124/0x180 mm/failslab.c:32 > should_failslab+0x9/0x14 mm/slab_common.c:1522 > slab_pre_alloc_hook mm/slab.h:423 [inline] > slab_alloc mm/slab.c:3378 [inline] > __do_kmalloc mm/slab.c:3716 [inline] > __kmalloc+0x63/0x760 mm/slab.c:3727 > kmalloc include/linux/slab.h:518 [inline] > tty_buffer_alloc drivers/tty/tty_buffer.c:170 [inline] > __tty_buffer_request_room+0x2d2/0x7f0 drivers/tty/tty_buffer.c:268 > tty_insert_flip_string_fixed_flag+0x8d/0x1f0 drivers/tty/tty_buffer.c:313 > tty_insert_flip_string include/linux/tty_flip.h:37 [inline] > pty_write+0x12c/0x1f0 drivers/tty/pty.c:121 > tty_put_char+0x129/0x150 drivers/tty/tty_io.c:2865 > __process_echoes+0x4d9/0x8d0 drivers/tty/n_tty.c:703 > process_echoes+0xfc/0x170 drivers/tty/n_tty.c:781 > n_tty_set_termios+0xb56/0xe80 drivers/tty/n_tty.c:1837 > tty_set_termios+0x7a0/0xac0 drivers/tty/tty_ioctl.c:341 > set_termios+0x41e/0x7d0 drivers/tty/tty_ioctl.c:414 > tty_mode_ioctl+0x535/0xb50 drivers/tty/tty_ioctl.c:747 > n_tty_ioctl_helper+0x54/0x3b0 drivers/tty/tty_ioctl.c:940 > n_tty_ioctl+0x54/0x320 drivers/tty/n_tty.c:2441 > tty_ioctl+0x5e1/0x1870 drivers/tty/tty_io.c:2655 > vfs_ioctl fs/ioctl.c:46 [inline] > file_ioctl fs/ioctl.c:500 [inline] > do_vfs_ioctl+0x1cf/0x16f0 fs/ioctl.c:684 > ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 > __do_sys_ioctl fs/ioctl.c:708 [inline] > __se_sys_ioctl fs/ioctl.c:706 [inline] > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 > do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x4559f9 > Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 > 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff > Lost 23 message(s)! > IPVS: length: 236 != 24 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x1b9/0x294 lib/dump_stack.c:113 > IPVS: length: 236 != 24 > fail_dump lib/fault-inject.c:51 [inline] > should_fail.cold.4+0xa/0x1a lib/fault-inject.c:149 > __should_failslab+0x124/0x180 mm/failslab.c:32 > should_failslab+0x9/0x14 mm/slab_common.c:1522 > slab_pre_alloc_hook mm/slab.h:423 [inline] > slab_alloc_node mm/slab.c:3299 [inline] > kmem_cache_alloc_node_trace+0x26f/0x770 mm/slab.c:3661 > __do_kmalloc_node mm/slab.c:3681 [inline] > __kmalloc_node_track_caller+0x33/0x70 mm/slab.c:3696 > __kmalloc_reserve.isra.39+0x3a/0xe0 net/core/skbuff.c:137 > __alloc_skb+0x14d/0x780 net/core/skbuff.c:205 > alloc_skb include/linux/skbuff.h:987 [inline] > netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline] > netlink_sendmsg+0xb01/0xfa0 net/netlink/af_netlink.c:1876 > sock_sendmsg_nosec net/socket.c:633 [inline] > sock_sendmsg+0xd5/0x120 net/socket.c:643 > ___sys_sendmsg+0x805/0x940 net/socket.c:2149 > __sys_sendmsg+0x115/0x270 net/socket.c:2187 > __do_sys_sendmsg net/socket.c:2196 [inline] > __se_sys_sendmsg net/socket.c:2194 [inline] > __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2194 > do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x4559f9 > Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 > 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff > 0f 83 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007fe47fbe2c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e > RAX: ffffffffffffffda RBX: 00007fe47fbe36d4 RCX: 00000000004559f9 > RDX: 0000000000000000 RSI: 0000000020000900 RDI: 0000000000000014 > RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000015 > R13: 00000000004c08de R14: 00000000004d00d8 R15: 0000000000000001 > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > nla_parse: 5 callbacks suppressed > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > netlink: 8 bytes leftover after parsing attributes in process > `syz-executor2'. > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > syzbot. > > -- > You received this message because you are subscribed to the Google Groups > "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/syzkaller-bugs/000000000000d557e7056e1c7a01%40google.com. > For more options, visit https://groups.google.com/d/optout.
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