* kernel BUG at mm/page_alloc.c:LINE!
@ 2019-01-17 2:33 syzbot
2019-01-17 8:33 ` Vlastimil Babka
0 siblings, 1 reply; 4+ messages in thread
From: syzbot @ 2019-01-17 2:33 UTC (permalink / raw)
To: akpm, iamjoonsoo.kim, linux-kernel, linux-mm, mgorman, mhocko,
sfr, syzkaller-bugs, vbabka
Hello,
syzbot found the following crash on:
HEAD commit: b808822a75a3 Add linux-next specific files for 20190111
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=16a471d8c00000
kernel config: https://syzkaller.appspot.com/x/.config?x=c052ead0aed5001b
dashboard link: https://syzkaller.appspot.com/bug?extid=80dd4798c16c634daf15
compiler: gcc (GCC) 9.0.0 20181231 (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+80dd4798c16c634daf15@syzkaller.appspotmail.com
------------[ cut here ]------------
kernel BUG at mm/page_alloc.c:3112!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 1043 Comm: kcompactd0 Not tainted 5.0.0-rc1-next-20190111 #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__isolate_free_page+0x4a8/0x680 mm/page_alloc.c:3112
Code: 4c 39 e3 77 c0 0f b6 8d 74 ff ff ff b8 01 00 00 00 48 d3 e0 e9 11 fd
ff ff 48 c7 c6 a0 63 52 88 4c 89 e7 e8 6a 14 10 00 0f 0b <0f> 0b 48 c7 c6
c0 64 52 88 4c 89 e7 e8 57 14 10 00 0f 0b 48 89 cf
RSP: 0000:ffff8880a78e6f58 EFLAGS: 00010007
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88812fffc7e0
RDX: 1ffff11025fff8fc RSI: 0000000000000007 RDI: ffff88812fffc7b0
RBP: ffff8880a78e7018 R08: ffff8880a78ce000 R09: ffffed1014f1cdf2
R10: ffffed1014f1cdf1 R11: 0000000000000003 R12: ffff88812fffc7b0
R13: 1ffff11014f1cdf2 R14: ffff88812fffc7b0 R15: ffff8880a78e6ff0
FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000438ca0 CR3: 0000000009871000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
fast_isolate_freepages mm/compaction.c:1356 [inline]
isolate_freepages mm/compaction.c:1429 [inline]
compaction_alloc+0xd05/0x2970 mm/compaction.c:1541
unmap_and_move mm/migrate.c:1177 [inline]
migrate_pages+0x48e/0x2cc0 mm/migrate.c:1417
compact_zone+0x2207/0x3e90 mm/compaction.c:2173
kcompactd_do_work+0x6de/0x1200 mm/compaction.c:2564
kcompactd+0x251/0x970 mm/compaction.c:2657
kthread+0x357/0x430 kernel/kthread.c:247
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Modules linked in:
======================================================
WARNING: possible circular locking dependency detected
5.0.0-rc1-next-20190111 #10 Not tainted
------------------------------------------------------
kcompactd0/1043 is trying to acquire lock:
00000000a0848583 (console_owner){-.-.}, at: log_next
kernel/printk/printk.c:499 [inline]
00000000a0848583 (console_owner){-.-.}, at: console_unlock+0x4ac/0x1040
kernel/printk/printk.c:2442
but task is already holding lock:
00000000c8e67de2 (&(&zone->lock)->rlock){..-.}, at: fast_isolate_freepages
mm/compaction.c:1313 [inline]
00000000c8e67de2 (&(&zone->lock)->rlock){..-.}, at: isolate_freepages
mm/compaction.c:1429 [inline]
00000000c8e67de2 (&(&zone->lock)->rlock){..-.}, at:
compaction_alloc+0x6f3/0x2970 mm/compaction.c:1541
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&(&zone->lock)->rlock){..-.}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152
rmqueue mm/page_alloc.c:3253 [inline]
get_page_from_freelist+0xf6c/0x4870 mm/page_alloc.c:3668
__alloc_pages_nodemask+0x4fd/0xdc0 mm/page_alloc.c:4714
alloc_pages_current+0x107/0x210 mm/mempolicy.c:2106
alloc_pages include/linux/gfp.h:509 [inline]
depot_save_stack+0x3da/0x460 lib/stackdepot.c:260
save_stack+0xa9/0xd0 mm/kasan/common.c:79
set_track mm/kasan/common.c:85 [inline]
__kasan_kmalloc mm/kasan/common.c:496 [inline]
__kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469
kasan_kmalloc mm/kasan/common.c:504 [inline]
kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:411
slab_post_alloc_hook mm/slab.h:440 [inline]
slab_alloc mm/slab.c:3381 [inline]
__do_kmalloc mm/slab.c:3709 [inline]
__kmalloc+0x145/0x740 mm/slab.c:3720
kmalloc include/linux/slab.h:550 [inline]
tty_buffer_alloc drivers/tty/tty_buffer.c:175 [inline]
__tty_buffer_request_room+0x2bf/0x7e0 drivers/tty/tty_buffer.c:273
tty_insert_flip_string_fixed_flag+0x93/0x1f0
drivers/tty/tty_buffer.c:318
tty_insert_flip_string include/linux/tty_flip.h:37 [inline]
pty_write+0x133/0x200 drivers/tty/pty.c:122
tty_put_char+0x137/0x160 drivers/tty/tty_io.c:3022
__process_echoes+0x5c8/0xa40 drivers/tty/n_tty.c:726
flush_echoes drivers/tty/n_tty.c:827 [inline]
__receive_buf drivers/tty/n_tty.c:1646 [inline]
n_tty_receive_buf_common+0xc2c/0x2f30 drivers/tty/n_tty.c:1740
n_tty_receive_buf2+0x34/0x40 drivers/tty/n_tty.c:1775
tty_ldisc_receive_buf+0xaf/0x1c0 drivers/tty/tty_buffer.c:461
tty_port_default_receive_buf+0x114/0x190 drivers/tty/tty_port.c:38
receive_buf drivers/tty/tty_buffer.c:481 [inline]
flush_to_ldisc+0x3b2/0x590 drivers/tty/tty_buffer.c:533
process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153
worker_thread+0x143/0x14a0 kernel/workqueue.c:2296
kthread+0x357/0x430 kernel/kthread.c:247
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
-> #2 (&(&port->lock)->rlock){-.-.}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152
tty_port_tty_get+0x22/0x80 drivers/tty/tty_port.c:287
tty_port_default_wakeup+0x16/0x40 drivers/tty/tty_port.c:47
tty_port_tty_wakeup+0x5d/0x70 drivers/tty/tty_port.c:387
uart_write_wakeup+0x46/0x70 drivers/tty/serial/serial_core.c:103
serial8250_tx_chars+0x4a4/0xb20
drivers/tty/serial/8250/8250_port.c:1806
serial8250_handle_irq.part.0+0x1be/0x2e0
drivers/tty/serial/8250/8250_port.c:1879
serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1865
[inline]
serial8250_default_handle_irq+0xc5/0x150
drivers/tty/serial/8250/8250_port.c:1895
serial8250_interrupt+0xfb/0x1a0
drivers/tty/serial/8250/8250_core.c:125
__handle_irq_event_percpu+0x1c6/0xb10 kernel/irq/handle.c:149
handle_irq_event_percpu+0xa0/0x1d0 kernel/irq/handle.c:189
handle_irq_event+0xa7/0x134 kernel/irq/handle.c:206
handle_edge_irq+0x232/0x8a0 kernel/irq/chip.c:791
generic_handle_irq_desc include/linux/irqdesc.h:154 [inline]
handle_irq+0x252/0x3d8 arch/x86/kernel/irq_64.c:78
do_IRQ+0x99/0x1d0 arch/x86/kernel/irq.c:246
ret_from_intr+0x0/0x1e
native_safe_halt+0x2/0x10 arch/x86/include/asm/irqflags.h:57
arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:555
default_idle_call+0x36/0x90 kernel/sched/idle.c:93
cpuidle_idle_call kernel/sched/idle.c:153 [inline]
do_idle+0x386/0x5d0 kernel/sched/idle.c:262
cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:353
start_secondary+0x435/0x620 arch/x86/kernel/smpboot.c:272
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243
-> #1 (&port_lock_key){-.-.}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152
serial8250_console_write+0x253/0xab0
drivers/tty/serial/8250/8250_port.c:3245
univ8250_console_write+0x5f/0x70
drivers/tty/serial/8250/8250_core.c:586
call_console_drivers kernel/printk/printk.c:1784 [inline]
console_unlock+0xc9a/0x1040 kernel/printk/printk.c:2455
vprintk_emit+0x370/0x960 kernel/printk/printk.c:1978
vprintk_default+0x28/0x30 kernel/printk/printk.c:2005
vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398
printk+0xba/0xed kernel/printk/printk.c:2038
register_console+0x74d/0xb50 kernel/printk/printk.c:2770
univ8250_console_init+0x3e/0x4b
drivers/tty/serial/8250/8250_core.c:681
console_init+0x6b7/0x9fe kernel/printk/printk.c:2856
start_kernel+0x5df/0x8bd init/main.c:667
x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470
x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:451
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243
-> #0 (console_owner){-.-.}:
lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3860
console_lock_spinning_enable kernel/printk/printk.c:1647 [inline]
console_unlock+0x516/0x1040 kernel/printk/printk.c:2452
vprintk_emit+0x370/0x960 kernel/printk/printk.c:1978
vprintk_default+0x28/0x30 kernel/printk/printk.c:2005
vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398
printk+0xba/0xed kernel/printk/printk.c:2038
report_bug.cold+0x11/0x5e lib/bug.c:191
fixup_bug arch/x86/kernel/traps.c:178 [inline]
fixup_bug arch/x86/kernel/traps.c:173 [inline]
do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:290
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
__ClearPageBuddy include/linux/page-flags.h:706 [inline]
rmv_page_order mm/page_alloc.c:744 [inline]
rmv_page_order mm/page_alloc.c:742 [inline]
__isolate_free_page+0x4a8/0x680 mm/page_alloc.c:3134
fast_isolate_freepages mm/compaction.c:1356 [inline]
isolate_freepages mm/compaction.c:1429 [inline]
compaction_alloc+0xd05/0x2970 mm/compaction.c:1541
unmap_and_move mm/migrate.c:1177 [inline]
migrate_pages+0x48e/0x2cc0 mm/migrate.c:1417
compact_zone+0x2207/0x3e90 mm/compaction.c:2173
kcompactd_do_work+0x6de/0x1200 mm/compaction.c:2564
kcompactd+0x251/0x970 mm/compaction.c:2657
kthread+0x357/0x430 kernel/kthread.c:247
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
other info that might help us debug this:
Chain exists of:
console_owner --> &(&port->lock)->rlock --> &(&zone->lock)->rlock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&(&zone->lock)->rlock);
lock(&(&port->lock)->rlock);
lock(&(&zone->lock)->rlock);
lock(console_owner);
*** DEADLOCK ***
2 locks held by kcompactd0/1043:
#0: 00000000c8e67de2 (&(&zone->lock)->rlock){..-.}, at:
fast_isolate_freepages mm/compaction.c:1313 [inline]
#0: 00000000c8e67de2 (&(&zone->lock)->rlock){..-.}, at: isolate_freepages
mm/compaction.c:1429 [inline]
#0: 00000000c8e67de2 (&(&zone->lock)->rlock){..-.}, at:
compaction_alloc+0x6f3/0x2970 mm/compaction.c:1541
#1: 0000000001912981 (console_lock){+.+.}, at: console_trylock_spinning
kernel/printk/printk.c:1709 [inline]
#1: 0000000001912981 (console_lock){+.+.}, at: vprintk_emit+0x351/0x960
kernel/printk/printk.c:1977
stack backtrace:
CPU: 0 PID: 1043 Comm: kcompactd0 Not tainted 5.0.0-rc1-next-20190111 #10
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+0x1db/0x2d0 lib/dump_stack.c:113
print_circular_bug.isra.0.cold+0x1cc/0x28f kernel/locking/lockdep.c:1225
check_prev_add kernel/locking/lockdep.c:1867 [inline]
check_prevs_add kernel/locking/lockdep.c:1980 [inline]
validate_chain kernel/locking/lockdep.c:2351 [inline]
__lock_acquire+0x2fed/0x4a10 kernel/locking/lockdep.c:3339
lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3860
console_lock_spinning_enable kernel/printk/printk.c:1647 [inline]
console_unlock+0x516/0x1040 kernel/printk/printk.c:2452
vprintk_emit+0x370/0x960 kernel/printk/printk.c:1978
vprintk_default+0x28/0x30 kernel/printk/printk.c:2005
vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398
printk+0xba/0xed kernel/printk/printk.c:2038
report_bug.cold+0x11/0x5e lib/bug.c:191
fixup_bug arch/x86/kernel/traps.c:178 [inline]
fixup_bug arch/x86/kernel/traps.c:173 [inline]
do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:290
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
RIP: 0010:__isolate_free_page+0x4a8/0x680 mm/page_alloc.c:3112
Code: 4c 39 e3 77 c0 0f b6 8d 74 ff ff ff b8 01 00 00 00 48 d3 e0 e9 11 fd
ff ff 48 c7 c6 a0 63 52 88 4c 89 e7 e8 6a 14 10 00 0f 0b <0f> 0b 48 c7 c6
c0 64 52 88 4c 89 e7 e8 57 14 10 00 0f 0b 48 89 cf
RSP: 0000:ffff8880a78e6f58 EFLAGS: 00010007
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88812fffc7e0
RDX: 1ffff11025fff8fc RSI: 0000000000000007 RDI: ffff88812fffc7b0
RBP: ffff8880a78e7018 R08: ffff8880a78ce000 R09: ffffed1014f1cdf2
R10: ffffed1014f1cdf1 R11: 0000000000000003 R12: ffff88812fffc7b0
R13: 1ffff11014f1cdf2 R14: ffff88812fffc7b0 R15: ffff8880a78e6ff0
fast_isolate_freepages mm/compaction.c:1356 [inline]
isolate_freepages mm/compaction.c:1429 [inline]
compaction_alloc+0xd05/0x2970 mm/compaction.c:1541
unmap_and_move mm/migrate.c:1177 [inline]
migrate_pages+0x48e/0x2cc0 mm/migrate.c:1417
compact_zone+0x2207/0x3e90 mm/compaction.c:2173
Lost 33 message(s)!
---[ end trace b088aebfc4c7ea50 ]---
RIP: 0010:__isolate_free_page+0x4a8/0x680 mm/page_alloc.c:3112
Code: 4c 39 e3 77 c0 0f b6 8d 74 ff ff ff b8 01 00 00 00 48 d3 e0 e9 11 fd
ff ff 48 c7 c6 a0 63 52 88 4c 89 e7 e8 6a 14 10 00 0f 0b <0f> 0b 48 c7 c6
c0 64 52 88 4c 89 e7 e8 57 14 10 00 0f 0b 48 89 cf
RSP: 0000:ffff8880a78e6f58 EFLAGS: 00010007
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88812fffc7e0
RDX: 1ffff11025fff8fc RSI: 0000000000000007 RDI: ffff88812fffc7b0
RBP: ffff8880a78e7018 R08: ffff8880a78ce000 R09: ffffed1014f1cdf2
R10: ffffed1014f1cdf1 R11: 0000000000000003 R12: ffff88812fffc7b0
R13: 1ffff11014f1cdf2 R14: ffff88812fffc7b0 R15: ffff8880a78e6ff0
FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000438ca0 CR3: 0000000009871000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: kernel BUG at mm/page_alloc.c:LINE!
2019-01-17 2:33 kernel BUG at mm/page_alloc.c:LINE! syzbot
@ 2019-01-17 8:33 ` Vlastimil Babka
2019-01-17 9:58 ` Dmitry Vyukov
2019-01-17 10:43 ` Mel Gorman
0 siblings, 2 replies; 4+ messages in thread
From: Vlastimil Babka @ 2019-01-17 8:33 UTC (permalink / raw)
To: syzbot, akpm, iamjoonsoo.kim, linux-kernel, linux-mm, mgorman,
mhocko, sfr, syzkaller-bugs
On 1/17/19 3:33 AM, syzbot wrote:
> Hello> syzbot found the following crash on:
>
> HEAD commit: b808822a75a3 Add linux-next specific files for 20190111
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=16a471d8c00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=c052ead0aed5001b
> dashboard link: https://syzkaller.appspot.com/bug?extid=80dd4798c16c634daf15
> compiler: gcc (GCC) 9.0.0 20181231 (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+80dd4798c16c634daf15@syzkaller.appspotmail.com
>
> ------------[ cut here ]------------
> kernel BUG at mm/page_alloc.c:3112!
Why does the mail subject say LINE, anyway?
> invalid opcode: 0000 [#1] PREEMPT SMP KASAN
> CPU: 0 PID: 1043 Comm: kcompactd0 Not tainted 5.0.0-rc1-next-20190111 #10
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> RIP: 0010:__isolate_free_page+0x4a8/0x680 mm/page_alloc.c:3112
That's BUG_ON(!PageBuddy(page)); in __isolate_free_page().
> Code: 4c 39 e3 77 c0 0f b6 8d 74 ff ff ff b8 01 00 00 00 48 d3 e0 e9 11 fd
> ff ff 48 c7 c6 a0 63 52 88 4c 89 e7 e8 6a 14 10 00 0f 0b <0f> 0b 48 c7 c6
> c0 64 52 88 4c 89 e7 e8 57 14 10 00 0f 0b 48 89 cf
> RSP: 0000:ffff8880a78e6f58 EFLAGS: 00010007
> RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88812fffc7e0
> RDX: 1ffff11025fff8fc RSI: 0000000000000007 RDI: ffff88812fffc7b0
> RBP: ffff8880a78e7018 R08: ffff8880a78ce000 R09: ffffed1014f1cdf2
> R10: ffffed1014f1cdf1 R11: 0000000000000003 R12: ffff88812fffc7b0
> R13: 1ffff11014f1cdf2 R14: ffff88812fffc7b0 R15: ffff8880a78e6ff0
> FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000438ca0 CR3: 0000000009871000 CR4: 00000000001426f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
> Call Trace:
> fast_isolate_freepages mm/compaction.c:1356 [inline]
Mel's new code... but might be just a victim of e.g. bad struct page
initialization?
> isolate_freepages mm/compaction.c:1429 [inline]
> compaction_alloc+0xd05/0x2970 mm/compaction.c:1541
> unmap_and_move mm/migrate.c:1177 [inline]
> migrate_pages+0x48e/0x2cc0 mm/migrate.c:1417
> compact_zone+0x2207/0x3e90 mm/compaction.c:2173
> kcompactd_do_work+0x6de/0x1200 mm/compaction.c:2564
> kcompactd+0x251/0x970 mm/compaction.c:2657
> kthread+0x357/0x430 kernel/kthread.c:247
> ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
> Modules linked in:
>
> ======================================================
> WARNING: possible circular locking dependency detected
> 5.0.0-rc1-next-20190111 #10 Not tainted
> ------------------------------------------------------
Dunno about that, but doesn't seem to be the root cause anyway.
> -> #0 (console_owner){-.-.}:
> lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3860
> console_lock_spinning_enable kernel/printk/printk.c:1647 [inline]
> console_unlock+0x516/0x1040 kernel/printk/printk.c:2452
> vprintk_emit+0x370/0x960 kernel/printk/printk.c:1978
> vprintk_default+0x28/0x30 kernel/printk/printk.c:2005
> vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398
> printk+0xba/0xed kernel/printk/printk.c:2038
> report_bug.cold+0x11/0x5e lib/bug.c:191
> fixup_bug arch/x86/kernel/traps.c:178 [inline]
> fixup_bug arch/x86/kernel/traps.c:173 [inline]
> do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
> do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:290
> invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
> __ClearPageBuddy include/linux/page-flags.h:706 [inline]
So that's VM_BUG_ON_PAGE(!Page##uname(page), page); in
__ClearPage##uname, so another problem with !PageBuddy.
> rmv_page_order mm/page_alloc.c:744 [inline]
> rmv_page_order mm/page_alloc.c:742 [inline]
> __isolate_free_page+0x4a8/0x680 mm/page_alloc.c:3134
But this is later in the function than the first BUG_ON, so something
has raced with us?
Also two kcompactd crashes with slightly different stacktraces, that
would have to be a NUMA system with multiple kcompactd's?
> fast_isolate_freepages mm/compaction.c:1356 [inline]
> isolate_freepages mm/compaction.c:1429 [inline]
> compaction_alloc+0xd05/0x2970 mm/compaction.c:1541
> unmap_and_move mm/migrate.c:1177 [inline]
> migrate_pages+0x48e/0x2cc0 mm/migrate.c:1417
> compact_zone+0x2207/0x3e90 mm/compaction.c:2173
> kcompactd_do_work+0x6de/0x1200 mm/compaction.c:2564
> kcompactd+0x251/0x970 mm/compaction.c:2657
> kthread+0x357/0x430 kernel/kthread.c:247
> ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: kernel BUG at mm/page_alloc.c:LINE!
2019-01-17 8:33 ` Vlastimil Babka
@ 2019-01-17 9:58 ` Dmitry Vyukov
2019-01-17 10:43 ` Mel Gorman
1 sibling, 0 replies; 4+ messages in thread
From: Dmitry Vyukov @ 2019-01-17 9:58 UTC (permalink / raw)
To: Vlastimil Babka
Cc: syzbot, Andrew Morton, Joonsoo Kim, LKML, Linux-MM, Mel Gorman,
Michal Hocko, Stephen Rothwell, syzkaller-bugs
On Thu, Jan 17, 2019 at 9:36 AM Vlastimil Babka <vbabka@suse.cz> wrote:
>
> On 1/17/19 3:33 AM, syzbot wrote:
> > Hello> syzbot found the following crash on:
> >
> > HEAD commit: b808822a75a3 Add linux-next specific files for 20190111
> > git tree: linux-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=16a471d8c00000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=c052ead0aed5001b
> > dashboard link: https://syzkaller.appspot.com/bug?extid=80dd4798c16c634daf15
> > compiler: gcc (GCC) 9.0.0 20181231 (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+80dd4798c16c634daf15@syzkaller.appspotmail.com
> >
> > ------------[ cut here ]------------
> > kernel BUG at mm/page_alloc.c:3112!
>
> Why does the mail subject say LINE, anyway?
The title is what syzbot uses as bug identity and for deduplication purposes.
We have to remove some moving parts, like lines/addresses/etc, so that
it does not create a new bug whenever the line changes:
https://github.com/google/syzkaller/blob/43689bcfed82ecb780bd0e54543609fe3c080623/pkg/report/report.go#L166-L168
> > invalid opcode: 0000 [#1] PREEMPT SMP KASAN
> > CPU: 0 PID: 1043 Comm: kcompactd0 Not tainted 5.0.0-rc1-next-20190111 #10
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> > Google 01/01/2011
> > RIP: 0010:__isolate_free_page+0x4a8/0x680 mm/page_alloc.c:3112
>
> That's BUG_ON(!PageBuddy(page)); in __isolate_free_page().
>
> > Code: 4c 39 e3 77 c0 0f b6 8d 74 ff ff ff b8 01 00 00 00 48 d3 e0 e9 11 fd
> > ff ff 48 c7 c6 a0 63 52 88 4c 89 e7 e8 6a 14 10 00 0f 0b <0f> 0b 48 c7 c6
> > c0 64 52 88 4c 89 e7 e8 57 14 10 00 0f 0b 48 89 cf
> > RSP: 0000:ffff8880a78e6f58 EFLAGS: 00010007
> > RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88812fffc7e0
> > RDX: 1ffff11025fff8fc RSI: 0000000000000007 RDI: ffff88812fffc7b0
> > RBP: ffff8880a78e7018 R08: ffff8880a78ce000 R09: ffffed1014f1cdf2
> > R10: ffffed1014f1cdf1 R11: 0000000000000003 R12: ffff88812fffc7b0
> > R13: 1ffff11014f1cdf2 R14: ffff88812fffc7b0 R15: ffff8880a78e6ff0
> > FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
> > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: 0000000000438ca0 CR3: 0000000009871000 CR4: 00000000001426f0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
> > Call Trace:
> > fast_isolate_freepages mm/compaction.c:1356 [inline]
>
> Mel's new code... but might be just a victim of e.g. bad struct page
> initialization?
>
> > isolate_freepages mm/compaction.c:1429 [inline]
> > compaction_alloc+0xd05/0x2970 mm/compaction.c:1541
> > unmap_and_move mm/migrate.c:1177 [inline]
> > migrate_pages+0x48e/0x2cc0 mm/migrate.c:1417
> > compact_zone+0x2207/0x3e90 mm/compaction.c:2173
> > kcompactd_do_work+0x6de/0x1200 mm/compaction.c:2564
> > kcompactd+0x251/0x970 mm/compaction.c:2657
> > kthread+0x357/0x430 kernel/kthread.c:247
> > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
> > Modules linked in:
> >
> > ======================================================
> > WARNING: possible circular locking dependency detected
> > 5.0.0-rc1-next-20190111 #10 Not tainted
> > ------------------------------------------------------
>
> Dunno about that, but doesn't seem to be the root cause anyway.
>
> > -> #0 (console_owner){-.-.}:
> > lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3860
> > console_lock_spinning_enable kernel/printk/printk.c:1647 [inline]
> > console_unlock+0x516/0x1040 kernel/printk/printk.c:2452
> > vprintk_emit+0x370/0x960 kernel/printk/printk.c:1978
> > vprintk_default+0x28/0x30 kernel/printk/printk.c:2005
> > vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398
> > printk+0xba/0xed kernel/printk/printk.c:2038
> > report_bug.cold+0x11/0x5e lib/bug.c:191
> > fixup_bug arch/x86/kernel/traps.c:178 [inline]
> > fixup_bug arch/x86/kernel/traps.c:173 [inline]
> > do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
> > do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:290
> > invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
> > __ClearPageBuddy include/linux/page-flags.h:706 [inline]
>
> So that's VM_BUG_ON_PAGE(!Page##uname(page), page); in
> __ClearPage##uname, so another problem with !PageBuddy.
>
> > rmv_page_order mm/page_alloc.c:744 [inline]
> > rmv_page_order mm/page_alloc.c:742 [inline]
> > __isolate_free_page+0x4a8/0x680 mm/page_alloc.c:3134
>
> But this is later in the function than the first BUG_ON, so something
> has raced with us?
>
> Also two kcompactd crashes with slightly different stacktraces, that
> would have to be a NUMA system with multiple kcompactd's?
>
> > fast_isolate_freepages mm/compaction.c:1356 [inline]
> > isolate_freepages mm/compaction.c:1429 [inline]
> > compaction_alloc+0xd05/0x2970 mm/compaction.c:1541
> > unmap_and_move mm/migrate.c:1177 [inline]
> > migrate_pages+0x48e/0x2cc0 mm/migrate.c:1417
> > compact_zone+0x2207/0x3e90 mm/compaction.c:2173
> > kcompactd_do_work+0x6de/0x1200 mm/compaction.c:2564
> > kcompactd+0x251/0x970 mm/compaction.c:2657
> > kthread+0x357/0x430 kernel/kthread.c:247
> > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
>
> --
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: kernel BUG at mm/page_alloc.c:LINE!
2019-01-17 8:33 ` Vlastimil Babka
2019-01-17 9:58 ` Dmitry Vyukov
@ 2019-01-17 10:43 ` Mel Gorman
1 sibling, 0 replies; 4+ messages in thread
From: Mel Gorman @ 2019-01-17 10:43 UTC (permalink / raw)
To: Vlastimil Babka
Cc: syzbot, akpm, iamjoonsoo.kim, linux-kernel, linux-mm, mhocko,
sfr, syzkaller-bugs
On Thu, Jan 17, 2019 at 09:33:09AM +0100, Vlastimil Babka wrote:
> > Code: 4c 39 e3 77 c0 0f b6 8d 74 ff ff ff b8 01 00 00 00 48 d3 e0 e9 11 fd
> > ff ff 48 c7 c6 a0 63 52 88 4c 89 e7 e8 6a 14 10 00 0f 0b <0f> 0b 48 c7 c6
> > c0 64 52 88 4c 89 e7 e8 57 14 10 00 0f 0b 48 89 cf
> > RSP: 0000:ffff8880a78e6f58 EFLAGS: 00010007
> > RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88812fffc7e0
> > RDX: 1ffff11025fff8fc RSI: 0000000000000007 RDI: ffff88812fffc7b0
> > RBP: ffff8880a78e7018 R08: ffff8880a78ce000 R09: ffffed1014f1cdf2
> > R10: ffffed1014f1cdf1 R11: 0000000000000003 R12: ffff88812fffc7b0
> > R13: 1ffff11014f1cdf2 R14: ffff88812fffc7b0 R15: ffff8880a78e6ff0
> > FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
> > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: 0000000000438ca0 CR3: 0000000009871000 CR4: 00000000001426f0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
> > Call Trace:
> > fast_isolate_freepages mm/compaction.c:1356 [inline]
>
> Mel's new code... but might be just a victim of e.g. bad struct page
> initialization?
>
The error looks like compaction found a !PageBuddy on the free lists
while the zone lock was held. That seems bad no matter what. I expect
there will be a respin of the entire series relatively soon but none of
the fixes so far would be for that level of damage.
--
Mel Gorman
SUSE Labs
^ permalink raw reply [flat|nested] 4+ messages in thread
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2019-01-17 2:33 kernel BUG at mm/page_alloc.c:LINE! syzbot
2019-01-17 8:33 ` Vlastimil Babka
2019-01-17 9:58 ` Dmitry Vyukov
2019-01-17 10:43 ` Mel Gorman
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