On Sat, Dec 23, 2017 at 12:48 AM, syzbot <bot+4e86372b8cb60e44613ff63e5dd1dcaffa7a4d29@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > syzkaller has found reproducer for the following crash on > 37759fa6d0fa9e4d6036d19ac12f555bfc0aeafd > git://git.cmpxchg.org/linux-mmots.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached. > C reproducer is attached > syzkaller reproducer is attached. See https://goo.gl/kgGztJ > for information about syzkaller reproducers I think this is fixed with: #syz fix: n_tty: fix EXTPROC vs ICANON interaction with TIOCINQ (aka FIONREAD) > INFO: rcu_sched self-detected stall on CPU > 1-...!: (124998 ticks this GP) idle=1aa/1/4611686018427387906 > softirq=6401/6401 fqs=178 > (t=125000 jiffies g=3233 c=3232 q=384) > rcu_sched kthread starved for 124263 jiffies! g3233 c3232 f0x0 > RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 > rcu_sched R running task 23272 8 2 0x80000000 > Call Trace: > context_switch kernel/sched/core.c:2800 [inline] > __schedule+0x8eb/0x2060 kernel/sched/core.c:3376 > schedule+0xf5/0x430 kernel/sched/core.c:3435 > schedule_timeout+0x13e/0x6f0 kernel/time/timer.c:1818 > rcu_gp_kthread+0x9dd/0x18e0 kernel/rcu/tree.c:2231 > kthread+0x33c/0x400 kernel/kthread.c:238 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524 > NMI backtrace for cpu 1 > CPU: 1 PID: 3169 Comm: syzkaller626814 Not tainted 4.15.0-rc4-mm1+ #49 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > <IRQ> > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x257 lib/dump_stack.c:53 > nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 > nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:62 > arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 > trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline] > rcu_dump_cpu_stacks+0x186/0x1de kernel/rcu/tree.c:1375 > print_cpu_stall kernel/rcu/tree.c:1524 [inline] > check_cpu_stall.isra.62+0xbb8/0x15b0 kernel/rcu/tree.c:1592 > __rcu_pending kernel/rcu/tree.c:3362 [inline] > rcu_pending kernel/rcu/tree.c:3424 [inline] > rcu_check_callbacks+0x238/0xd20 kernel/rcu/tree.c:2764 > update_process_times+0x30/0x60 kernel/time/timer.c:1630 > tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:162 > tick_sched_timer+0x42/0x120 kernel/time/tick-sched.c:1148 > __run_hrtimer kernel/time/hrtimer.c:1210 [inline] > __hrtimer_run_queues+0x358/0xe20 kernel/time/hrtimer.c:1274 > hrtimer_interrupt+0x1c2/0x5e0 kernel/time/hrtimer.c:1308 > local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline] > smp_apic_timer_interrupt+0x14a/0x700 arch/x86/kernel/apic/apic.c:1050 > apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:920 > </IRQ> > RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:332 [inline] > RIP: 0010:inq_canon drivers/tty/n_tty.c:2409 [inline] > RIP: 0010:n_tty_ioctl+0x218/0x2d0 drivers/tty/n_tty.c:2429 > RSP: 0018:ffff8801c914fb48 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff11 > RAX: 0000000000000643 RBX: ffffc900018c3060 RCX: ffffffff8293be5c > RDX: 0000000000000000 RSI: 00000000749d30db RDI: ffffc900018c4260 > RBP: ffff8801c914fb88 R08: 1ffff10039229e99 R09: 0000000000000004 > R10: ffff8801c914f988 R11: 0000000000000003 R12: ffffc900018c2000 > R13: 00000002e0efd643 R14: 0000000020a6bffc R15: ffff8801c8493938 > tty_ioctl+0x336/0x1610 drivers/tty/tty_io.c:2640 > vfs_ioctl fs/ioctl.c:46 [inline] > do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 > SYSC_ioctl fs/ioctl.c:701 [inline] > SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 > entry_SYSCALL_64_fastpath+0x1f/0x96 > RIP: 0033:0x445b39 > RSP: 002b:00007f6ed1479d18 EFLAGS: 00000293 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 00000000006dac3c RCX: 0000000000445b39 > RDX: 0000000020a6bffc RSI: 000000000000541b RDI: 0000000000000013 > RBP: 00000000006dac38 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000293 R12: 6d74702f7665642f > R13: 00007ffe16e1657f R14: 00007f6ed147a9c0 R15: 0000000000000008 > > -- > 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@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit > https://groups.google.com/d/msgid/syzkaller-bugs/089e082bdf106667a50560f672cc%40google.com. > > For more options, visit https://groups.google.com/d/optout. -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
