RAX: ffffffffffffffda RBX: 00007effca6f7c90 RCX: 0000000000457ec9
RDX: 0000000020000180 RSI: 0000000020000080 RDI: 0000000000000000
RBP: 000000000073bf00 R08: 0000000020000500 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007effca6f86d4
R13: 00000000004c3a5a R14: 00000000004d66a0 R15: 0000000000000007
BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
#PF error: [WRITE]
PGD 8d086067 P4D 8d086067 PUD 8d087067 PMD 0 
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 12996 Comm: syz-executor1 Not tainted 4.20.0+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:init_arraycache mm/slab.c:562 [inline]
RIP: 0010:__alloc_alien_cache mm/slab.c:669 [inline]
RIP: 0010:alloc_alien_cache mm/slab.c:689 [inline]
RIP: 0010:setup_kmem_cache_node+0x1f9/0x420 mm/slab.c:910
Code: 48 0f a3 05 51 22 96 08 73 5a 48 8b 4d b0 44 89 e2 44 89 f6 48 8b 7d a0 4c 8d 2c c1 e8 40 ea ff ff 48 83 f8 c8 49 89 c7 74 17 <c7> 40 38 00 00 00 00 8b 45 b8 41 89 47 3c b8 0d f0 ad ba 49 89 47
RSP: 0018:ffff88804d857500 EFLAGS: 00010213
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000200000
RDX: 000000000c3ff180 RSI: 00000000000000a8 RDI: ffff88812c3f0040
RBP: ffff88804d857568 R08: ffff88804f352600 R09: ffffed1015ce5b90
R10: ffffed1015ce5b8f R11: ffff8880ae72dc7b R12: 0000000000000000
R13: ffff888092e81608 R14: 00000000006000c0 R15: 0000000000000000
FS:  00007effca6f8700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000038 CR3: 000000009865b000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 setup_kmem_cache_nodes mm/slab.c:3819 [inline]
 __do_tune_cpucache+0x161/0x220 mm/slab.c:3889
 do_tune_cpucache+0x25/0xd0 mm/slab.c:3898
 enable_cpucache+0x3e/0xd0 mm/slab.c:3979
 setup_cpu_cache+0xd4/0x1e0 mm/slab.c:1821
 __kmem_cache_create+0x1bb/0x270 mm/slab.c:2134
 create_cache+0xd4/0x200 mm/slab_common.c:391
 kmem_cache_create_usercopy+0x1a5/0x260 mm/slab_common.c:489
 p9_client_create+0xd78/0x16e1 net/9p/client.c:1054
 v9fs_session_init+0x1f3/0x1be0 fs/9p/v9fs.c:421
 v9fs_mount+0x7d/0x920 fs/9p/vfs_super.c:135
 mount_fs+0xae/0x331 fs/super.c:1261
 vfs_kern_mount.part.0+0xdb/0x570 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2469 [inline]
 do_mount+0x576/0x3110 fs/namespace.c:2801
 ksys_mount+0xdb/0x150 fs/namespace.c:3017
 __do_sys_mount fs/namespace.c:3031 [inline]
 __se_sys_mount fs/namespace.c:3028 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3028
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457ec9
Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007effca6f7c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007effca6f7c90 RCX: 0000000000457ec9
RDX: 0000000020000180 RSI: 0000000020000080 RDI: 0000000000000000
RBP: 000000000073bf00 R08: 0000000020000500 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007effca6f86d4
R13: 00000000004c3a5a R14: 00000000004d66a0 R15: 0000000000000007
Modules linked in:
CR2: 0000000000000038
---[ end trace 7c15d8533d03031b ]---
RIP: 0010:init_arraycache mm/slab.c:562 [inline]
RIP: 0010:__alloc_alien_cache mm/slab.c:669 [inline]
RIP: 0010:alloc_alien_cache mm/slab.c:689 [inline]
RIP: 0010:setup_kmem_cache_node+0x1f9/0x420 mm/slab.c:910
kobject: 'rx-0' (000000005c5ff364): kobject_cleanup, parent 00000000e9e937b5
Code: 48 0f a3 05 51 22 96 08 73 5a 48 8b 4d b0 44 89 e2 44 89 f6 48 8b 7d a0 4c 8d 2c c1 e8 40 ea ff ff 48 83 f8 c8 49 89 c7 74 17 <c7> 40 38 00 00 00 00 8b 45 b8 41 89 47 3c b8 0d f0 ad ba 49 89 47
kobject: 'rx-0' (000000005c5ff364): auto cleanup 'remove' event
RSP: 0018:ffff88804d857500 EFLAGS: 00010213
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000200000
kobject: 'rx-0' (000000005c5ff364): kobject_uevent_env
RDX: 000000000c3ff180 RSI: 00000000000000a8 RDI: ffff88812c3f0040
kobject: 'rx-0' (000000005c5ff364): kobject_uevent_env: uevent_suppress caused the event to drop!
RBP: ffff88804d857568 R08: ffff88804f352600 R09: ffffed1015ce5b90
R10: ffffed1015ce5b8f R11: ffff8880ae72dc7b R12: 0000000000000000
R13: ffff888092e81608 R14: 00000000006000c0 R15: 0000000000000000
FS:  00007effca6f8700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000038 CR3: 000000009865b000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400