general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 16066 Comm: syz-executor.5 Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dequeue_head net/sched/sch_fq_codel.c:120 [inline] RIP: 0010:fq_codel_drop net/sched/sch_fq_codel.c:168 [inline] RIP: 0010:fq_codel_enqueue+0xa75/0x11b0 net/sched/sch_fq_codel.c:230 Code: 22 fb 44 3b 64 24 70 0f 83 dd 00 00 00 e8 23 28 22 fb 48 8b 44 24 40 80 38 00 0f 85 5a 05 00 00 49 8b 06 48 89 c2 48 c1 ea 03 <42> 80 3c 2a 00 0f 85 52 05 00 00 48 8b 10 49 89 16 48 89 c2 48 c1 RSP: 0018:ffffc900019476a0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9001459e000 RDX: 0000000000000000 RSI: ffffffff86510c6d RDI: 0000000000000000 RBP: ffffc900019477b0 R08: ffff8880915a44c0 R09: fffffbfff1862756 R10: ffffffff8c313aaf R11: fffffbfff1862755 R12: 0000000000000400 R13: dffffc0000000000 R14: ffff888045860000 R15: ffffc90001947880 FS: 00007f771d901700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31825000 CR3: 00000000a22a4000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __dev_xmit_skb net/core/dev.c:3710 [inline] __dev_queue_xmit+0x154a/0x3070 net/core/dev.c:4021 packet_snd net/packet/af_packet.c:2979 [inline] packet_sendmsg+0x23cc/0x5ce0 net/packet/af_packet.c:3004 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 sock_write_iter+0x289/0x3c0 net/socket.c:1004 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write+0x4a2/0x700 fs/read_write.c:484 __vfs_write+0xc9/0x100 fs/read_write.c:497 vfs_write+0x268/0x5d0 fs/read_write.c:559 ksys_write+0x1ee/0x250 fs/read_write.c:612 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c829 Code: 0d 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f771d900c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000050c1c0 RCX: 000000000045c829 RDX: 000000000000002c RSI: 0000000020000200 RDI: 0000000000000005 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000cdc R14: 00000000004cf063 R15: 00007f771d9016d4 Modules linked in: ---[ end trace 17d6aeceaf889266 ]--- RIP: 0010:dequeue_head net/sched/sch_fq_codel.c:120 [inline] RIP: 0010:fq_codel_drop net/sched/sch_fq_codel.c:168 [inline] RIP: 0010:fq_codel_enqueue+0xa75/0x11b0 net/sched/sch_fq_codel.c:230 Code: 22 fb 44 3b 64 24 70 0f 83 dd 00 00 00 e8 23 28 22 fb 48 8b 44 24 40 80 38 00 0f 85 5a 05 00 00 49 8b 06 48 89 c2 48 c1 ea 03 <42> 80 3c 2a 00 0f 85 52 05 00 00 48 8b 10 49 89 16 48 89 c2 48 c1 RSP: 0018:ffffc900019476a0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9001459e000 RDX: 0000000000000000 RSI: ffffffff86510c6d RDI: 0000000000000000 RBP: ffffc900019477b0 R08: ffff8880915a44c0 R09: fffffbfff1862756 R10: ffffffff8c313aaf R11: fffffbfff1862755 R12: 0000000000000400 R13: dffffc0000000000 R14: ffff888045860000 R15: ffffc90001947880 FS: 00007f771d901700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31825000 CR3: 00000000a22a4000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400