Re: BUG: sleeping function called from invalid context in __alloc_pages_nodemask

[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit:    419593da Add linux-next specific files for 20191129
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=177a9712e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7c04b0959e75c206
dashboard link: https://syzkaller.appspot.com/bug?extid=4925d60532bf4c399608
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16148e9ce00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12a1f786e00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+4925d60532bf4c399608@xxxxxxxxxxxxxxxxxxxxxxxxx

BUG: sleeping function called from invalid context at mm/page_alloc.c:4681
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 9065, name:  
kworker/1:3
4 locks held by kworker/1:3/9065:
 #0: ffff8880aa026d28 ((wq_completion)events){+.+.}, at: __write_once_size  
include/linux/compiler.h:247 [inline]
 #0: ffff8880aa026d28 ((wq_completion)events){+.+.}, at: arch_atomic64_set  
arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff8880aa026d28 ((wq_completion)events){+.+.}, at: atomic64_set  
include/asm-generic/atomic-instrumented.h:868 [inline]
 #0: ffff8880aa026d28 ((wq_completion)events){+.+.}, at: atomic_long_set  
include/asm-generic/atomic-long.h:40 [inline]
 #0: ffff8880aa026d28 ((wq_completion)events){+.+.}, at: set_work_data  
kernel/workqueue.c:615 [inline]
 #0: ffff8880aa026d28 ((wq_completion)events){+.+.}, at:  
set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline]
 #0: ffff8880aa026d28 ((wq_completion)events){+.+.}, at:  
process_one_work+0x88b/0x1740 kernel/workqueue.c:2235
 #1: ffffc90002177dc0 (pcpu_balance_work){+.+.}, at:  
process_one_work+0x8c1/0x1740 kernel/workqueue.c:2239
 #2: ffffffff8983ff20 (pcpu_alloc_mutex){+.+.}, at:  
pcpu_balance_workfn+0xb7/0x1310 mm/percpu.c:1845
 #3: ffffffff89851b18 (vmap_area_lock){+.+.}, at: spin_lock  
include/linux/spinlock.h:338 [inline]
 #3: ffffffff89851b18 (vmap_area_lock){+.+.}, at:  
pcpu_get_vm_areas+0x3b27/0x3f00 mm/vmalloc.c:3431
Preemption disabled at:
[<ffffffff81a89ce7>] spin_lock include/linux/spinlock.h:338 [inline]
[<ffffffff81a89ce7>] pcpu_get_vm_areas+0x3b27/0x3f00 mm/vmalloc.c:3431
CPU: 1 PID: 9065 Comm: kworker/1:3 Not tainted  
5.4.0-next-20191129-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: events pcpu_balance_workfn
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 ___might_sleep.cold+0x1fb/0x23e kernel/sched/core.c:6800
 __might_sleep+0x95/0x190 kernel/sched/core.c:6753
 prepare_alloc_pages mm/page_alloc.c:4681 [inline]
 __alloc_pages_nodemask+0x523/0x910 mm/page_alloc.c:4730
 alloc_pages_current+0x107/0x210 mm/mempolicy.c:2211
 alloc_pages include/linux/gfp.h:532 [inline]
 __get_free_pages+0xc/0x40 mm/page_alloc.c:4786
 kasan_populate_vmalloc_pte mm/kasan/common.c:762 [inline]
 kasan_populate_vmalloc_pte+0x2f/0x1c0 mm/kasan/common.c:753
 apply_to_pte_range mm/memory.c:2041 [inline]
 apply_to_pmd_range mm/memory.c:2068 [inline]
 apply_to_pud_range mm/memory.c:2088 [inline]
 apply_to_p4d_range mm/memory.c:2108 [inline]
 apply_to_page_range+0x445/0x700 mm/memory.c:2133
 kasan_populate_vmalloc+0x68/0x90 mm/kasan/common.c:791
 pcpu_get_vm_areas+0x3c77/0x3f00 mm/vmalloc.c:3439
 pcpu_create_chunk+0x24e/0x7f0 mm/percpu-vm.c:340
 pcpu_balance_workfn+0xf1b/0x1310 mm/percpu.c:1934
 process_one_work+0x9af/0x1740 kernel/workqueue.c:2264
 worker_thread+0x98/0xe40 kernel/workqueue.c:2410
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352