BUG: unable to handle kernel NULL pointer dereference at 0000000000000074 PGD 16290e067 P4D 16290e067 PUD 1c9e99067 PMD 0 Oops: 0000 [#1] SMP KASAN CPU: 1 PID: 8870 Comm: syz-executor2 Tainted: G W 4.18.0-rc4-next-20180713+ #7 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:virt_to_cache mm/slab.c:400 [inline] RIP: 0010:kfree+0xb2/0x260 mm/slab.c:3809 Code: 48 89 df 48 b8 00 00 00 00 00 ea ff ff 48 c1 ea 0c 48 c1 e2 06 48 01 c2 48 8b 42 08 a8 01 48 8d 48 ff 48 0f 45 d1 4c 8b 6a 18 <49> 63 75 74 e8 e5 c0 a3 ff 49 63 75 74 48 89 df e8 d9 8f a9 01 4c RSP: 0018:ffff8801963feeb8 EFLAGS: 00010046 RAX: ffffea0000054008 RBX: ffffffff81500cc9 RCX: ffffea0000054007 RDX: ffffea0000054000 RSI: ffffffff81a635f1 RDI: ffffffff81500cc9 RBP: ffff8801963feed8 R08: ffff880191a04300 R09: ffffed003ae212a0 R10: ffffed003ae212a0 R11: ffff8801d7109507 R12: 0000000000000282 R13: 0000000000000000 R14: ffff880195d40ed8 R15: ffffffff81500cc9 FS: 00007feffa02a700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000074 CR3: 0000000195cc6000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kfree_const+0x59/0x70 mm/util.c:38 kobject_cleanup lib/kobject.c:649 [inline] kobject_release lib/kobject.c:672 [inline] kref_put include/linux/kref.h:70 [inline] kobject_put+0x1af/0x280 lib/kobject.c:689 shrink_slab_memcg mm/vmscan.c:598 [inline] shrink_slab+0x861/0xa60 mm/vmscan.c:671 shrink_node+0x429/0x16a0 mm/vmscan.c:2735 shrink_zones mm/vmscan.c:2964 [inline] do_try_to_free_pages+0x3e7/0x1290 mm/vmscan.c:3026 try_to_free_mem_cgroup_pages+0x49d/0xc90 mm/vmscan.c:3324 memory_high_write+0x283/0x310 mm/memcontrol.c:5611 cgroup_file_write+0x31f/0x840 kernel/cgroup/cgroup.c:3502 kernfs_fop_write+0x2ba/0x480 fs/kernfs/file.c:316 __vfs_write+0x117/0x9d0 fs/read_write.c:485 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455ab9 Code: 1d ba 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 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007feffa029c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007feffa02a6d4 RCX: 0000000000455ab9 RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000018 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004c2c77 R14: 00000000004d4c80 R15: 0000000000000000 Modules linked in: Dumping ftrace buffer: (ftrace buffer empty) CR2: 0000000000000074 ---[ end trace 4578d5d357e1b158 ]--- RIP: 0010:virt_to_cache mm/slab.c:400 [inline] RIP: 0010:kfree+0xb2/0x260 mm/slab.c:3809 Code: 48 89 df 48 b8 00 00 00 00 00 ea ff ff 48 c1 ea 0c 48 c1 e2 06 48 01 c2 48 8b 42 08 a8 01 48 8d 48 ff 48 0f 45 d1 4c 8b 6a 18 <49> 63 75 74 e8 e5 c0 a3 ff 49 63 75 74 48 89 df e8 d9 8f a9 01 4c RSP: 0018:ffff8801963feeb8 EFLAGS: 00010046 RAX: ffffea0000054008 RBX: ffffffff81500cc9 RCX: ffffea0000054007 RDX: ffffea0000054000 RSI: ffffffff81a635f1 RDI: ffffffff81500cc9 RBP: ffff8801963feed8 R08: ffff880191a04300 R09: ffffed003ae212a0 R10: ffffed003ae212a0 R11: ffff8801d7109507 R12: 0000000000000282 R13: 0000000000000000 R14: ffff880195d40ed8 R15: ffffffff81500cc9 FS: 00007feffa02a700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000074 CR3: 0000000195cc6000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400