general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] CPU: 0 PID: 17853 Comm: syz-executor.0 Not tainted 5.15.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:pcpu_get_page_chunk mm/percpu.c:266 [inline] RIP: 0010:pcpu_chunk_addr_search mm/percpu.c:1622 [inline] RIP: 0010:free_percpu mm/percpu.c:2281 [inline] RIP: 0010:free_percpu+0x182/0x10b0 mm/percpu.c:2264 Code: 80 3c 02 00 0f 85 8e 0e 00 00 48 8b 3b 48 01 ef e8 e3 22 0a 00 48 ba 00 00 00 00 00 fc ff df 48 8d 78 20 48 89 f9 48 c1 e9 03 <80> 3c 11 00 0f 85 36 0e 00 00 48 8b 58 20 48 b8 00 00 00 00 00 fc RSP: 0018:ffffc90004267c18 EFLAGS: 00010002 RAX: 0000000000000000 RBX: ffff88823ffe3c00 RCX: 0000000000000004 RDX: dffffc0000000000 RSI: ffffffff81b155ff RDI: 0000000000000020 RBP: ffffe8ffffafff60 R08: 0000000000000000 R09: 0000000000000003 R10: ffffffff81b15780 R11: 0000000000000002 R12: ffff8880b9c33000 R13: 0000607f45efff60 R14: ffff88823ffe3a08 R15: 0000000000000003 FS: 00007f5a93b4f700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7c167e0382 CR3: 0000000053345000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: tun_free_netdev+0x78/0x140 drivers/net/tun.c:2203 netdev_run_todo+0x6b4/0xa80 net/core/dev.c:10593 __tun_chr_ioctl.isra.0+0x993/0x4230 drivers/net/tun.c:3297 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f5a965d8709 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5a93b4f188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5a966dcf60 RCX: 00007f5a965d8709 RDX: 0000000020000000 RSI: 00000000400454ca RDI: 0000000000000006 RBP: 00007f5a96632cb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffea7a6e0f R14: 00007f5a93b4f300 R15: 0000000000022000 Modules linked in: ---[ end trace 475788eb04e33d06 ]--- RIP: 0010:pcpu_get_page_chunk mm/percpu.c:266 [inline] RIP: 0010:pcpu_chunk_addr_search mm/percpu.c:1622 [inline] RIP: 0010:free_percpu mm/percpu.c:2281 [inline] RIP: 0010:free_percpu+0x182/0x10b0 mm/percpu.c:2264 Code: 80 3c 02 00 0f 85 8e 0e 00 00 48 8b 3b 48 01 ef e8 e3 22 0a 00 48 ba 00 00 00 00 00 fc ff df 48 8d 78 20 48 89 f9 48 c1 e9 03 <80> 3c 11 00 0f 85 36 0e 00 00 48 8b 58 20 48 b8 00 00 00 00 00 fc RSP: 0018:ffffc90004267c18 EFLAGS: 00010002 RAX: 0000000000000000 RBX: ffff88823ffe3c00 RCX: 0000000000000004 RDX: dffffc0000000000 RSI: ffffffff81b155ff RDI: 0000000000000020 RBP: ffffe8ffffafff60 R08: 0000000000000000 R09: 0000000000000003 R10: ffffffff81b15780 R11: 0000000000000002 R12: ffff8880b9c33000 R13: 0000607f45efff60 R14: ffff88823ffe3a08 R15: 0000000000000003 FS: 00007f5a93b4f700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7c167e0382 CR3: 0000000053345000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 4: 0f 85 8e 0e 00 00 jne 0xe98 a: 48 8b 3b mov (%rbx),%rdi d: 48 01 ef add %rbp,%rdi 10: e8 e3 22 0a 00 callq 0xa22f8 15: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 1c: fc ff df 1f: 48 8d 78 20 lea 0x20(%rax),%rdi 23: 48 89 f9 mov %rdi,%rcx 26: 48 c1 e9 03 shr $0x3,%rcx * 2a: 80 3c 11 00 cmpb $0x0,(%rcx,%rdx,1) <-- trapping instruction 2e: 0f 85 36 0e 00 00 jne 0xe6a 34: 48 8b 58 20 mov 0x20(%rax),%rbx 38: 48 rex.W 39: b8 00 00 00 00 mov $0x0,%eax 3e: 00 fc add %bh,%ah