general protection fault, probably for non-canonical address 0xdffffc000000008f: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000478-0x000000000000047f] CPU: 0 PID: 9060 Comm: syz-executor.0 Not tainted 5.6.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:hlist_add_head_rcu include/linux/rculist.h:538 [inline] RIP: 0010:qdisc_hash_add.part.0+0xc3/0x260 net/sched/sch_api.c:279 Code: 69 6b 38 47 86 c8 61 4c 8d 7b 28 48 b8 00 00 00 00 00 fc ff df c1 ed 1c 4d 8d ac ee 78 04 00 00 4c 89 ea 4c 89 ef 48 c1 ea 03 <80> 3c 02 00 0f 85 7b 01 00 00 4c 89 fa 49 8b ac ee 78 04 00 00 48 RSP: 0018:ffffc9000874fb48 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffffffff8a387fc0 RCX: ffffc9000a4fb000 RDX: 000000000000008f RSI: ffffffff86278e92 RDI: 0000000000000478 RBP: 0000000000000000 R08: ffff8880a846a300 R09: fffffbfff1469d6d R10: fffffbfff1469d6c R11: ffffffff8a34eb67 R12: 0000000000000000 R13: 0000000000000478 R14: 0000000000000000 R15: ffffffff8a387fe8 FS: 00007fdb5a656700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d33c000 CR3: 00000000a863e000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: qdisc_hash_add+0xa5/0xc0 net/sched/sch_api.c:283 dev_qdisc_set_real_num_tx_queues+0x19b/0x250 net/sched/sch_generic.c:1287 netif_set_real_num_tx_queues+0x25b/0x700 net/core/dev.c:2878 tun_set_real_num_queues drivers/net/tun.c:598 [inline] tun_attach+0x549/0x1550 drivers/net/tun.c:845 tun_set_iff drivers/net/tun.c:2704 [inline] __tun_chr_ioctl+0x1ff7/0x4120 drivers/net/tun.c:3043 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c679 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fdb5a655c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fdb5a6566d4 RCX: 000000000045c679 RDX: 0000000020000040 RSI: 00000000400454ca RDI: 0000000000000004 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000005a2 R14: 00000000004c81e0 R15: 000000000076bf0c Modules linked in: ---[ end trace 8425aade7660b28a ]--- RIP: 0010:hlist_add_head_rcu include/linux/rculist.h:538 [inline] RIP: 0010:qdisc_hash_add.part.0+0xc3/0x260 net/sched/sch_api.c:279 Code: 69 6b 38 47 86 c8 61 4c 8d 7b 28 48 b8 00 00 00 00 00 fc ff df c1 ed 1c 4d 8d ac ee 78 04 00 00 4c 89 ea 4c 89 ef 48 c1 ea 03 <80> 3c 02 00 0f 85 7b 01 00 00 4c 89 fa 49 8b ac ee 78 04 00 00 48 RSP: 0018:ffffc9000874fb48 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffffffff8a387fc0 RCX: ffffc9000a4fb000 RDX: 000000000000008f RSI: ffffffff86278e92 RDI: 0000000000000478 RBP: 0000000000000000 R08: ffff8880a846a300 R09: fffffbfff1469d6d R10: fffffbfff1469d6c R11: ffffffff8a34eb67 R12: 0000000000000000 R13: 0000000000000478 R14: 0000000000000000 R15: ffffffff8a387fe8 FS: 00007fdb5a656700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2c52e000 CR3: 00000000a863e000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400