WARNING in pcpu_alloc

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 09eb2ba5 ANDROID: x86_64_cuttlefish_defconfig: Enable lz4 ..
git tree: android-4.9
console output: https://syzkaller.appspot.com/x/log.txt?x=12b5cce1400000
kernel config: https://syzkaller.appspot.com/x/.config?x=18438f2a4429a3c4
dashboard link: https://syzkaller.appspot.com/bug?extid=5e34ec0c4a00d39535f9
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15ca207c400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1537ae0a400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+5e34ec...@syzkaller.appspotmail.com

random: crng init done
------------[ cut here ]------------
WARNING: CPU: 0 PID: 2113 at mm/percpu.c:892 pcpu_alloc+0x7aa/0xad0
mm/percpu.c:891
illegal size (32816) or align (8) for percpu allocation
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 2113 Comm: syz-executor146 Not tainted 4.9.124+ #32
ffff8801ca1b79a0 ffffffff81af4529 ffffffff82838de0 00000000ffffffff
0000000000000000 0000000000000000 000000000000037c ffff8801ca1b7a60
ffffffff813f1b55 0000000041b58ab3 ffffffff82c2889b ffffffff813f1996
Call Trace:
[<ffffffff81af4529>] __dump_stack lib/dump_stack.c:15 [inline]
[<ffffffff81af4529>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
[<ffffffff813f1b55>] panic+0x1bf/0x39f kernel/panic.c:179
[<ffffffff813f1e24>] __warn.cold.9+0xc1/0x17f kernel/panic.c:542
[<ffffffff810dcd52>] warn_slowpath_fmt+0xc2/0x100 kernel/panic.c:565
[<ffffffff8146ca1a>] pcpu_alloc+0x7aa/0xad0 mm/percpu.c:891
[<ffffffff8146cd67>] __alloc_percpu_gfp+0x27/0x30 mm/percpu.c:1066
[<ffffffff813adb3f>] alloc_extra_elems kernel/bpf/hashtab.c:133 [inline]
[<ffffffff813adb3f>] htab_map_alloc+0x75f/0xec0 kernel/bpf/hashtab.c:243
[<ffffffff8139871a>] find_and_alloc_map kernel/bpf/syscall.c:38 [inline]
[<ffffffff8139871a>] map_create kernel/bpf/syscall.c:259 [inline]
[<ffffffff8139871a>] SYSC_bpf kernel/bpf/syscall.c:1019 [inline]
[<ffffffff8139871a>] SyS_bpf+0x16ba/0x2620 kernel/bpf/syscall.c:972
[<ffffffff8100554f>] do_syscall_64+0x19f/0x480 arch/x86/entry/common.c:282
[<ffffffff8278ba53>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Dumping ftrace buffer:
(ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..


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