general protection fault, probably for non-canonical address 0xdffffc00000000cd: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000668-0x000000000000066f] CPU: 0 PID: 4827 Comm: kworker/0:3 Not tainted 5.12.0-rc8-next-20210423-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: cgroup_destroy css_free_rwork_fn RIP: 0010:css_free_rwork_fn+0xe2/0x10f0 kernel/cgroup/cgroup.c:4928 Code: ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 64 04 00 00 48 8d 7d 20 8b 5b a0 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 9d 0d 00 00 4c 89 f7 ff 55 20 48 c7 c7 e0 bd fb RSP: 0018:ffffc9000b8e7cc8 EFLAGS: 00010203 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 00000000000000cd RSI: ffffffff816e6972 RDI: 000000000000066e RBP: 000000000000064e R08: 0000000000000001 R09: ffffffff90207957 R10: 0000000000000001 R11: 0000000000084087 R12: 00000870ffffea00 R13: ffff8880290a0000 R14: ffff888014528000 R15: ffff8880b9c34a80 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe2b482f6b8 CR3: 0000000024405000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Modules linked in: ---[ end trace ca06c9e83614f55b ]--- RIP: 0010:css_free_rwork_fn+0xe2/0x10f0 kernel/cgroup/cgroup.c:4928 Code: ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 64 04 00 00 48 8d 7d 20 8b 5b a0 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 9d 0d 00 00 4c 89 f7 ff 55 20 48 c7 c7 e0 bd fb RSP: 0018:ffffc9000b8e7cc8 EFLAGS: 00010203 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 00000000000000cd RSI: ffffffff816e6972 RDI: 000000000000066e RBP: 000000000000064e R08: 0000000000000001 R09: ffffffff90207957 R10: 0000000000000001 R11: 0000000000084087 R12: 00000870ffffea00 R13: ffff8880290a0000 R14: ffff888014528000 R15: ffff8880b9c34a80 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff17803f028 CR3: 0000000013177000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400