list_add corruption. next->prev should be prev (0000000065a8bcf9), but was 00000000fa1ecf26. (next=00000000fa1ecf26).
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:25!
invalid opcode: 0000 [#1] SMP PTI
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 9497 Comm: syz-executor7 Not tainted 4.16.0+ #87
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__list_add_valid+0x275/0x450 lib/list_debug.c:23
RSP: 0018:ffff8801a9a4f160 EFLAGS: 00010082
RAX: 0000000000000075 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88021fd30418
RBP: ffff8801a9a4f1c8 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88021fffab28
R13: ffff88021fffab28 R14: 0000000000000000 R15: ffffffff8b314000
FS:  00007fc5ea7d1700(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3280447010 CR3: 00000001812cc000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __list_add include/linux/list.h:60 [inline]
 list_add include/linux/list.h:79 [inline]
 __free_one_page+0x1483/0x1800 mm/page_alloc.c:915
 free_pcppages_bulk+0x785/0xe60 mm/page_alloc.c:1168
 free_unref_page_commit+0x36a/0x530 mm/page_alloc.c:2678
 free_unref_page mm/page_alloc.c:2695 [inline]
 __free_pages+0x1b9/0x240 mm/page_alloc.c:4321
 kmsan_free_page+0x197/0x2e0 mm/kmsan/kmsan.c:938
 free_pages_prepare mm/page_alloc.c:1035 [inline]
 free_pcp_prepare mm/page_alloc.c:1099 [inline]
 free_unref_page_prepare+0x22f/0x620 mm/page_alloc.c:2641
 free_unref_page+0x82/0x120 mm/page_alloc.c:2691
 __put_single_page mm/swap.c:79 [inline]
 __put_page+0xbb/0x1e0 mm/swap.c:113
 put_page include/linux/mm.h:865 [inline]
 free_page_and_swap_cache+0x48b/0x540 mm/swap_state.c:307
 __tlb_remove_table arch/x86/include/asm/tlb.h:30 [inline]
 tlb_remove_table+0x95/0x4d0 mm/memory.c:383
 ___pte_free_tlb+0xa6/0xc0 arch/x86/mm/pgtable.c:60
 __pte_free_tlb arch/x86/include/asm/pgalloc.h:73 [inline]
 free_pte_range mm/memory.c:446 [inline]
 free_pmd_range mm/memory.c:464 [inline]
 free_pud_range mm/memory.c:498 [inline]
 free_p4d_range mm/memory.c:532 [inline]
 free_pgd_range+0xae7/0x1ad0 mm/memory.c:612
 free_pgtables+0x535/0x650 mm/memory.c:644
 exit_mmap+0x46c/0x950 mm/mmap.c:3039
 __mmput+0x16c/0x610 kernel/fork.c:961
 mmput+0xab/0xf0 kernel/fork.c:982
 exit_mm+0x6ed/0x7a0 kernel/exit.c:545
 do_exit+0xc01/0x38d0 kernel/exit.c:854
 do_group_exit+0x1a0/0x360 kernel/exit.c:970
 SYSC_exit_group+0x21/0x30 kernel/exit.c:981
 SyS_exit_group+0x25/0x30 kernel/exit.c:979
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x455389
RSP: 002b:0000000020e68a48 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000000b RCX: 0000000000455389
RDX: 0000000000455389 RSI: 0000000020e68a80 RDI: 000000000000000b
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020a46000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000051 R14: 00000000006f3838 R15: 0000000000000000
Code: 87 80 0c 00 00 00 00 00 00 41 c7 87 20 03 00 00 00 00 00 00 48 c7 c7 68 f6 82 8a 31 c0 48 89 d6 4c 89 ea 4c 89 e1 e8 fb ac 51 fd <0f> 0b 66 0f 1f 84 00 00 00 00 00 eb fe 48 8b 7d c8 e8 c5 88 cb 
RIP: __list_add_valid+0x275/0x450 lib/list_debug.c:23 RSP: ffff8801a9a4f160
---[ end trace c8438ed17c022487 ]---