Messages in this thread | | | Date | Sun, 13 May 2018 14:40:52 -0700 | From | Eric Biggers <> | Subject | Re: general protection fault in account_system_index_time |
| |
On Wed, Mar 28, 2018 at 12:01:02AM -0700, syzbot wrote: > Hello, > > syzbot hit the following crash on upstream commit > 3eb2ce825ea1ad89d20f7a3b5780df850e4be274 (Sun Mar 25 22:44:30 2018 +0000) > Linux 4.16-rc7 > syzbot dashboard link: > https://syzkaller.appspot.com/bug?extid=bab86ea70f6f74bd9199 > > So far this crash happened 2 times on upstream. > C reproducer: https://syzkaller.appspot.com/x/repro.c?id=4644092092874752 > syzkaller reproducer: > https://syzkaller.appspot.com/x/repro.syz?id=4728333984071680 > Raw console output: > https://syzkaller.appspot.com/x/log.txt?id=6080200710291456 > Kernel config: > https://syzkaller.appspot.com/x/.config?id=-8440362230543204781 > compiler: gcc (GCC) 7.1.1 20170620 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+bab86ea70f6f74bd9199@syzkaller.appspotmail.com > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. > > IPVS: ftp: loaded support on port[0] = 21 > kasan: CONFIG_KASAN_INLINE enabled > kasan: CONFIG_KASAN_INLINE enabled > kasan: GPF could be caused by NULL-ptr deref or user memory access > kasan: GPF could be caused by NULL-ptr deref or user memory access > general protection fault: 0000 [#1] SMP KASAN > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 0 PID: 164097 Comm: � Not tainted 4.16.0-rc7+ #368 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline] > RIP: 0010:get_running_cputimer include/linux/sched/cputime.h:85 [inline] > RIP: 0010:account_group_system_time include/linux/sched/cputime.h:149 > [inline] > RIP: 0010:account_system_index_time+0xdd/0x5e0 kernel/sched/cputime.c:172 > RSP: 0018:ffff8801db207930 EFLAGS: 00010006 > RAX: 0002810100028101 RBX: ffff8801b22d0300 RCX: 0000502020005047 > RDX: dffffc0000000000 RSI: 00000000000f4240 RDI: 0002810100028239 > RBP: ffff8801db207a10 R08: 0000000000028101 R09: fffffbfff0f6a2bb > R10: ffff8801db2079e8 R11: fffffbfff0f6a2ba R12: 1ffff1003b640f29 > R13: 000000000002c5c0 R14: 00000000000f4240 R15: 0000000000000002 > FS: 00000000019fd880(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000421d60 CR3: 00000001b1963003 CR4: 00000000001606f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <IRQ> > account_system_time+0x7f/0xb0 kernel/sched/cputime.c:203 > account_process_tick+0xd4/0x3e0 kernel/sched/cputime.c:502 > update_process_times+0x23/0x60 kernel/time/timer.c:1634 > tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:162 > tick_sched_timer+0x42/0x120 kernel/time/tick-sched.c:1194 > __run_hrtimer kernel/time/hrtimer.c:1349 [inline] > __hrtimer_run_queues+0x39c/0xec0 kernel/time/hrtimer.c:1411 > hrtimer_interrupt+0x2a5/0x6f0 kernel/time/hrtimer.c:1469 > 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+0xf/0x20 arch/x86/entry/entry_64.S:857 > </IRQ> > Code: ea 03 80 3c 02 00 0f 85 8b 04 00 00 48 8b 83 f8 06 00 00 48 ba 00 00 > 00 00 00 fc ff df 48 8d b8 38 01 00 00 48 89 f9 48 c1 e9 03 <0f> b6 14 11 48 > 89 f9 83 e1 07 38 ca 7f 08 84 d2 0f 85 90 03 00 > RIP: __read_once_size include/linux/compiler.h:188 [inline] RSP: > ffff8801db207930 > RIP: get_running_cputimer include/linux/sched/cputime.h:85 [inline] RSP: > ffff8801db207930 > RIP: account_group_system_time include/linux/sched/cputime.h:149 [inline] > RSP: ffff8801db207930 > RIP: account_system_index_time+0xdd/0x5e0 kernel/sched/cputime.c:172 RSP: > ffff8801db207930 > > ====================================================== > WARNING: possible circular locking dependency detected > 4.16.0-rc7+ #368 Not tainted > ------------------------------------------------------ > rcu_sched/8 is trying to acquire lock: > ((console_sem).lock){..-.}, at: [<0000000011a525fb>] down_trylock+0x13/0x70 > kernel/locking/semaphore.c:136 > > but task is already holding lock: > (&rq->lock){-.-.}, at: [<000000004637b5ed>] rq_lock_irqsave > kernel/sched/sched.h:1744 [inline] > (&rq->lock){-.-.}, at: [<000000004637b5ed>] load_balance+0xb10/0x34c0 > kernel/sched/fair.c:8548 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #2 (&rq->lock){-.-.}: > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144 > rq_lock kernel/sched/sched.h:1760 [inline] > task_fork_fair+0x7a/0x690 kernel/sched/fair.c:9471 > sched_fork+0x450/0xc10 kernel/sched/core.c:2405 > copy_process.part.38+0x17c9/0x4bd0 kernel/fork.c:1763 > copy_process kernel/fork.c:1606 [inline] > _do_fork+0x1f7/0xf70 kernel/fork.c:2087 > kernel_thread+0x34/0x40 kernel/fork.c:2146 > rest_init+0x22/0xf0 init/main.c:403 > start_kernel+0x7f1/0x819 init/main.c:717 > x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378 > x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 > secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:239 > > -> #1 (&p->pi_lock){-.-.}: > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 > try_to_wake_up+0xbc/0x15f0 kernel/sched/core.c:1989 > wake_up_process+0x10/0x20 kernel/sched/core.c:2152 > __up.isra.0+0x1cc/0x2c0 kernel/locking/semaphore.c:262 > up+0x13b/0x1d0 kernel/locking/semaphore.c:187 > __up_console_sem+0xb2/0x1a0 kernel/printk/printk.c:242 > console_unlock+0x5af/0xfb0 kernel/printk/printk.c:2417 > do_con_write+0x106e/0x1f70 drivers/tty/vt/vt.c:2433 > con_write+0x25/0xb0 drivers/tty/vt/vt.c:2782 > process_output_block drivers/tty/n_tty.c:579 [inline] > n_tty_write+0x5ef/0xec0 drivers/tty/n_tty.c:2308 > do_tty_write drivers/tty/tty_io.c:958 [inline] > tty_write+0x3fa/0x840 drivers/tty/tty_io.c:1042 > __vfs_write+0xef/0x970 fs/read_write.c:480 > vfs_write+0x189/0x510 fs/read_write.c:544 > SYSC_write fs/read_write.c:589 [inline] > SyS_write+0xef/0x220 fs/read_write.c:581 > do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > > -> #0 ((console_sem).lock){..-.}: > lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 > down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 > __down_trylock_console_sem+0xa2/0x1e0 kernel/printk/printk.c:225 > console_trylock+0x15/0x70 kernel/printk/printk.c:2229 > console_trylock_spinning kernel/printk/printk.c:1643 [inline] > vprintk_emit+0x5b5/0xb90 kernel/printk/printk.c:1906 > vprintk_default+0x28/0x30 kernel/printk/printk.c:1947 > vprintk_func+0x57/0xc0 kernel/printk/printk_safe.c:379 > printk+0xaa/0xca kernel/printk/printk.c:1980 > kasan_die_handler+0x31/0x3f arch/x86/mm/kasan_init_64.c:247 > notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93 > __atomic_notifier_call_chain kernel/notifier.c:183 [inline] > atomic_notifier_call_chain+0x77/0x140 kernel/notifier.c:193 > notify_die+0x18c/0x280 kernel/notifier.c:549 > do_general_protection+0x331/0x3e0 arch/x86/kernel/traps.c:558 > general_protection+0x25/0x50 arch/x86/entry/entry_64.S:1150 > task_group kernel/sched/sched.h:1203 [inline] > can_migrate_task+0xe2/0x1c20 kernel/sched/fair.c:7102 > detach_tasks kernel/sched/fair.c:7251 [inline] > load_balance+0xdab/0x34c0 kernel/sched/fair.c:8555 > idle_balance kernel/sched/fair.c:8837 [inline] > pick_next_task_fair+0xe03/0x1630 kernel/sched/fair.c:6757 > pick_next_task kernel/sched/core.c:3286 [inline] > __schedule+0x4fc/0x1ec0 kernel/sched/core.c:3414 > schedule+0xf5/0x430 kernel/sched/core.c:3499 > schedule_timeout+0x118/0x230 kernel/time/timer.c:1801 > rcu_gp_kthread+0x9dd/0x18e0 kernel/rcu/tree.c:2230 > kthread+0x33c/0x400 kernel/kthread.c:238 > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 > > other info that might help us debug this: > > Chain exists of: > (console_sem).lock --> &p->pi_lock --> &rq->lock > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(&rq->lock); > lock(&p->pi_lock); > lock(&rq->lock); > lock((console_sem).lock); > > *** DEADLOCK *** > > 3 locks held by rcu_sched/8: > #0: (rcu_read_lock){....}, at: [<0000000024de6645>] rcu_read_lock+0x0/0x70 > include/linux/compiler.h:188 > #1: (&rq->lock){-.-.}, at: [<000000004637b5ed>] rq_lock_irqsave > kernel/sched/sched.h:1744 [inline] > #1: (&rq->lock){-.-.}, at: [<000000004637b5ed>] load_balance+0xb10/0x34c0 > kernel/sched/fair.c:8548 > #2: (rcu_read_lock){....}, at: [<00000000c60bf25c>] rcu_read_unlock > include/linux/rcupdate.h:682 [inline] > #2: (rcu_read_lock){....}, at: [<00000000c60bf25c>] > atomic_notifier_call_chain+0x0/0x140 kernel/notifier.c:184 > > stack backtrace: > CPU: 1 PID: 8 Comm: rcu_sched Not tainted 4.16.0-rc7+ #368 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x24d lib/dump_stack.c:53 > print_circular_bug.isra.38+0x2cd/0x2dc kernel/locking/lockdep.c:1223 > check_prev_add kernel/locking/lockdep.c:1863 [inline] > check_prevs_add kernel/locking/lockdep.c:1976 [inline] > validate_chain kernel/locking/lockdep.c:2417 [inline] > __lock_acquire+0x30a8/0x3e00 kernel/locking/lockdep.c:3431 > lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 > down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 > __down_trylock_console_sem+0xa2/0x1e0 kernel/printk/printk.c:225 > console_trylock+0x15/0x70 kernel/printk/printk.c:2229 > console_trylock_spinning kernel/printk/printk.c:1643 [inline] > vprintk_emit+0x5b5/0xb90 kernel/printk/printk.c:1906 > vprintk_default+0x28/0x30 kernel/printk/printk.c:1947 > vprintk_func+0x57/0xc0 kernel/printk/printk_safe.c:379 > printk+0xaa/0xca kernel/printk/printk.c:1980 > kasan_die_handler+0x31/0x3f arch/x86/mm/kasan_init_64.c:247 > notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93 > __atomic_notifier_call_chain kernel/notifier.c:183 [inline] > atomic_notifier_call_chain+0x77/0x140 kernel/notifier.c:193 > notify_die+0x18c/0x280 kernel/notifier.c:549 > do_general_protection+0x331/0x3e0 arch/x86/kernel/traps.c:558 > general_protection+0x25/0x50 arch/x86/entry/entry_64.S:1150 > RIP: 0010:task_group kernel/sched/sched.h:1203 [inline] > RIP: 0010:can_migrate_task+0xe2/0x1c20 kernel/sched/fair.c:7102 > RSP: 0018:ffff8801d9af6c88 EFLAGS: 00010006 > RAX: dffffc0000000000 RBX: 0002810100028101 RCX: ffff8801d9af7098 > RDX: ffff8801d9af6d30 RSI: 000050202000503c RDI: 00028101000281e1 > RBP: ffff8801d9af6d58 R08: 1ffff1003b35ed9a R09: ffff88021fff8048 > R10: 0000000000000001 R11: ffff88021fff805d R12: ffff8801b22d0300 > R13: ffffffff87d5df20 R14: ffff8801b22d0300 R15: ffff8801b22d03f0 > detach_tasks kernel/sched/fair.c:7251 [inline] > load_balance+0xdab/0x34c0 kernel/sched/fair.c:8555 > idle_balance kernel/sched/fair.c:8837 [inline] > pick_next_task_fair+0xe03/0x1630 kernel/sched/fair.c:6757 > pick_next_task kernel/sched/core.c:3286 [inline] > __schedule+0x4fc/0x1ec0 kernel/sched/core.c:3414 > schedule+0xf5/0x430 kernel/sched/core.c:3499 > schedule_timeout+0x118/0x230 kernel/time/timer.c:1801 > rcu_gp_kthread+0x9dd/0x18e0 kernel/rcu/tree.c:2230 > ? __schedule+0x1 > Lost 10 message(s)! > ---[ end trace 948581b189460493 ]--- > general protection fault: 0000 [#2] SMP KASAN > Dumping ftrace buffer: > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@googlegroups.com. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug is > merged > into any tree, please reply to this email with: > #syz fix: exact-commit-title
This was fixed by commit ae4745730cf8e69:
#syz fix: net: Fix untag for vlan packets without ethernet header
- Eric
| |