INFO: task hung in vm_mmap_pgoff

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 62872f95 Merge 4.4.174 into android-4.4
git tree: android-4.4
console output: https://syzkaller.appspot.com/x/log.txt?x=11be6ea7400000
kernel config: https://syzkaller.appspot.com/x/.config?x=47bc4dd423780c4a
dashboard link: https://syzkaller.appspot.com/bug?extid=764c16cdbab5575cf0d6
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
userspace arch: i386

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+764c16...@syzkaller.appspotmail.com

Free memory is -5928kB above reserved
lowmemorykiller: Killing 'syz-executor.1' (22790) (tgid 22790), adj 1000,
to free 43740kB on behalf of 'getty' (22452) because
cache 100kB is below limit 6144kB for oom_score_adj 0
Free memory is -5928kB above reserved
INFO: task syz-executor.5:22785 blocked for more than 140 seconds.
Not tainted 4.4.174+ #17
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5 D ffff8801780b7be8 28984 22785 2125 0x20020000
ffff8801780b7be8 0000000000000006 ffff8800bb8b8000 dffffc0000000000
ffff8801780b7bd0 ffffffff811fef00 ffff8801db61f180 ffff8801db61f1a8
ffff8801db61e898 ffff8801d43717c0 ffff8800bb8b8000 ffffed002f016001
Call Trace:
[<ffffffff82709b79>] schedule+0x99/0x1d0 kernel/sched/core.c:3355
[<ffffffff827150e1>] rwsem_down_write_failed
kernel/locking/rwsem-xadd.c:489 [inline]
[<ffffffff827150e1>] rwsem_down_write_failed+0x511/0xa80
kernel/locking/rwsem-xadd.c:437
[<ffffffff81add6e3>] call_rwsem_down_write_failed+0x13/0x20
arch/x86/lib/rwsem.S:99
[<ffffffff81409d77>] vm_mmap_pgoff+0x137/0x1c0 mm/util.c:295
[<ffffffff81447b9d>] SYSC_mmap_pgoff mm/mmap.c:1523 [inline]
[<ffffffff81447b9d>] SyS_mmap_pgoff+0x14d/0x1b0 mm/mmap.c:1481
[<ffffffff8100603d>] do_syscall_32_irqs_on arch/x86/entry/common.c:330
[inline]
[<ffffffff8100603d>] do_fast_syscall_32+0x32d/0xa90
arch/x86/entry/common.c:397
[<ffffffff8271a350>] sysenter_flags_fixed+0xd/0x1a
lowmemorykiller: Killing 'syz-executor.1' (22790) (tgid 22790), adj 1000,
to free 43740kB on behalf of 'syz-fuzzer' (2075) because
cache 100kB is below limit 6144kB for oom_score_adj 0
Free memory is -5928kB above reserved
lowmemorykiller: Killing 'syz-executor.1' (22790) (tgid 22790), adj 1000,
to free 43740kB on behalf of 'syz-executor.1' (22793) because
cache 100kB is below limit 6144kB for oom_score_adj 0
Free memory is -5928kB above reserved
1 lock held by syz-executor.5/22785:
#0: (&mm->mmap_sem){++++++}, at: [<ffffffff81409d77>]
vm_mmap_pgoff+0x137/0x1c0 mm/util.c:295
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 20 Comm: khungtaskd Not tainted 4.4.174+ #17
task: ffff8801da6f4740 task.stack: ffff8800001d0000
RIP: 0010:[<ffffffff8109b617>] [<ffffffff8109b617>] _flat_send_IPI_mask
arch/x86/kernel/apic/apic_flat_64.c:62 [inline]
RIP: 0010:[<ffffffff8109b617>] [<ffffffff8109b617>]
flat_send_IPI_mask+0xf7/0x1b0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0000:ffff8800001d7c88 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fc300
RBP: ffff8800001d7cb8 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000003000000 R14: ffffffff82e5f2e0 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000040f460 CR3: 000000010ed31000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
0000000000000001 ffffffff82e5f2e0 ffffffff831a6ac0 fffffbfff0634c34
000000000001b6c0 0000000000000008 ffff8800001d7cd8 ffffffff81092bee
0000000000000008 ffffffff82924260 ffff8800001d7d30 ffffffff81ab8252
Call Trace:
[<ffffffff81092bee>] nmi_raise_cpu_backtrace+0x5e/0x80
arch/x86/kernel/apic/hw_nmi.c:33
[<ffffffff81ab8252>] nmi_trigger_all_cpu_backtrace.cold+0xa1/0xae
lib/nmi_backtrace.c:85
[<ffffffff81092ca4>] arch_trigger_all_cpu_backtrace+0x14/0x20
arch/x86/kernel/apic/hw_nmi.c:38
[<ffffffff813b4762>] trigger_all_cpu_backtrace include/linux/nmi.h:44
[inline]
[<ffffffff813b4762>] check_hung_task kernel/hung_task.c:125 [inline]
[<ffffffff813b4762>] check_hung_uninterruptible_tasks
kernel/hung_task.c:182 [inline]
[<ffffffff813b4762>] watchdog.cold+0xd3/0xee kernel/hung_task.c:238
[<ffffffff811342c3>] kthread+0x273/0x310 kernel/kthread.c:211
[<ffffffff82718fc5>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:537
Code: 00 c3 5f ff 80 e6 10 75 e1 41 c1 e5 18 44 89 2c 25 10 c3 5f ff 44 89
fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 c3 5f ff <41> f7 c4 00
02 00 00 75 1e 4c 89 e7 57 9d 0f 1f 44 00 00 e8 f1
NMI backtrace for cpu 1
CPU: 1 PID: 22452 Comm: getty Not tainted 4.4.174+ #17
task: ffff8800bae28000 task.stack: ffff880107970000
RIP: 0010:[<ffffffff81205faf>] [<ffffffff81205faf>] arch_local_irq_restore
arch/x86/include/asm/paravirt.h:812 [inline]
RIP: 0010:[<ffffffff81205faf>] [<ffffffff81205faf>]
lock_acquire+0x19f/0x450 kernel/locking/lockdep.c:3595
RSP: 0018:ffff8801079772d0 EFLAGS: 00000246
RAX: 0000000000000007 RBX: ffff8800bae28000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000246
RBP: ffff880107977340 R08: 0000000000000004 R09: ffff8800bae28988
R10: ffffffff82836880 R11: 0000000000000000 R12: ffffffff82ea73a0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002
FS: 00007fd5cd3a4700(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000040320a CR3: 0000000108cc0000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
0000000000000000 ffffffff813c27e0 0000000500000000 ffff880000000000
0000000000000246 ffffffff00000000 ffff880100000006 0000000000000000
0000000000000246 ffff8801d89aaf80 dffffc0000000000 ffff8801d89aaf80
Call Trace:
[<ffffffff813c2826>] rcu_lock_acquire include/linux/rcupdate.h:477 [inline]
[<ffffffff813c2826>] rcu_read_lock include/linux/rcupdate.h:861 [inline]
[<ffffffff813c2826>] find_lock_task_mm+0x46/0x280 mm/oom_kill.c:106
[<ffffffff8211e7cb>] lowmem_scan+0x45b/0xbf0
drivers/staging/android/lowmemorykiller.c:132
[<ffffffff813ee8e2>] do_shrink_slab mm/vmscan.c:357 [inline]
[<ffffffff813ee8e2>] shrink_slab.part.0+0x402/0xb30 mm/vmscan.c:455
[<ffffffff813f742c>] shrink_slab mm/vmscan.c:425 [inline]
[<ffffffff813f742c>] shrink_zone+0x4bc/0x610 mm/vmscan.c:2448
[<ffffffff813f7bef>] shrink_zones mm/vmscan.c:2603 [inline]
[<ffffffff813f7bef>] do_try_to_free_pages mm/vmscan.c:2653 [inline]
[<ffffffff813f7bef>] try_to_free_pages+0x66f/0x1260 mm/vmscan.c:2861
[<ffffffff813d09af>] __perform_reclaim mm/page_alloc.c:2915 [inline]
[<ffffffff813d09af>] __alloc_pages_direct_reclaim mm/page_alloc.c:2936
[inline]
[<ffffffff813d09af>] __alloc_pages_slowpath mm/page_alloc.c:3201 [inline]
[<ffffffff813d09af>] __alloc_pages_nodemask+0x8af/0x14b0
mm/page_alloc.c:3313
[<ffffffff813dc242>] __alloc_pages include/linux/gfp.h:415 [inline]
[<ffffffff813dc242>] __alloc_pages_node include/linux/gfp.h:428 [inline]
[<ffffffff813dc242>] alloc_pages_node include/linux/gfp.h:442 [inline]
[<ffffffff813dc242>] __page_cache_alloc include/linux/pagemap.h:226
[inline]
[<ffffffff813dc242>] page_cache_alloc_readahead
include/linux/pagemap.h:242 [inline]
[<ffffffff813dc242>] __do_page_cache_readahead+0x222/0x840
mm/readahead.c:184
[<ffffffff813bf6de>] ra_submit mm/internal.h:55 [inline]
[<ffffffff813bf6de>] do_sync_mmap_readahead mm/filemap.c:1917 [inline]
[<ffffffff813bf6de>] filemap_fault+0x74e/0xc10 mm/filemap.c:1994
[<ffffffff81665ed2>] ext4_filemap_fault+0x72/0xa0 fs/ext4/inode.c:5558
[<ffffffff8142e82a>] __do_fault+0x1ca/0x350 mm/memory.c:2822
[<ffffffff8143b9cc>] do_read_fault mm/memory.c:3012 [inline]
[<ffffffff8143b9cc>] do_fault mm/memory.c:3177 [inline]
[<ffffffff8143b9cc>] handle_pte_fault mm/memory.c:3346 [inline]
[<ffffffff8143b9cc>] __handle_mm_fault mm/memory.c:3474 [inline]
[<ffffffff8143b9cc>] handle_mm_fault+0x1cfc/0x3140 mm/memory.c:3503
[<ffffffff810aaa4e>] __do_page_fault+0x28e/0x7f0 arch/x86/mm/fault.c:1243
[<ffffffff810ab008>] do_page_fault+0x28/0x30 arch/x86/mm/fault.c:1306
[<ffffffff82719e35>] page_fault+0x25/0x30 arch/x86/entry/entry_64.S:1064
Code: ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85
d9 01 00 00 c7 83 c4 08 00 00 00 00 00 00 48 8b 7d d0 57 9d <0f> 1f 44 00
00 48 83 c4 48 5b 41 5c 41 5d 41 5e 41 5f 5d c3 65
lowmemorykiller: Killing 'syz-executor.1' (22790) (tgid 22790), adj 1000,
to free 43740kB on behalf of 'getty' (22451) because
cache 100kB is below limit 6144kB for oom_score_adj 0
Free memory is -5928kB above reserved
lowmemorykiller: Killing 'syz-executor.1' (22790) (tgid 22790), adj 1000,
to free 43740kB on behalf of 'syz-executor.4' (22795) because
cache 100kB is below limit 6144kB for oom_score_adj 0
Free memory is -5928kB above reserved
lowmemorykiller: Killing 'syz-executor.1' (22790) (tgid 22790), adj 1000,
to free 43740kB on behalf of 'getty' (22448) because
cache 100kB is below limit 6144kB for oom_score_adj 0
Free memory is -5928kB above reserved
lowmemorykiller: Killing 'syz-executor.1' (22790) (tgid 22790), adj 1000,
to free 43740kB on behalf of 'getty' (22450) because
cache 100kB is below limit 6144kB for oom_score_adj 0
Free memory is -5928kB above reserved
lowmemorykiller: Killing 'syz-executor.1' (22790) (tgid 22790), adj 1000,
to free 43740kB on behalf of 'syz-executor.2' (22770) because
cache 100kB is below limit 6144kB for oom_score_adj 0
Free memory is -5928kB above reserved
lowmemorykiller: Killing 'syz-executor.1' (22790) (tgid 22790), adj 1000,
to free 43740kB on behalf of 'getty' (22447) because
cache 100kB is below limit 6144kB for oom_score_adj 0
Free memory is -5928kB above reserved
lowmemorykiller: Killing 'syz-executor.1' (22790) (tgid 22790), adj 1000,
to free 43740kB on behalf of 'syz-executor.0' (22771) because
cache 100kB is below limit 6144kB for oom_score_adj 0
Free memory is -5928kB above reserved
lowmemorykiller: Killing 'syz-executor.1' (22790) (tgid 22790), adj 1000,
to free 43740kB on behalf of 'syz-fuzzer' (2073) because
cache 100kB is below limit 6144kB for oom_score_adj 0
Free memory is -5928kB above reserved
lowmemorykiller: Killing 'syz-executor.1' (22790) (tgid 22790), adj 1000,
to free 43740kB on behalf of 'syz-executor.1' (22793) because
cache 100kB is below limit 6144kB for oom_score_adj 0
Free memory is -5928kB above reserved
lowmemorykiller: Killing 'syz-executor.1' (22790) (tgid 22790), adj 1000,
to free 43740kB on behalf of 'udevd' (468) because
cache 100kB is below limit 6144kB for oom_score_adj 0
Free memory is -5928kB above reserved


---
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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.