Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 3 UID: 0 PID: 1137 Comm: kworker/u32:6 Not tainted 6.13.0-rc5-syzkaller-00012-g0bc21e701a6f #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events_unbound flush_to_ldisc RIP: 0010:_compound_head include/linux/page-flags.h:242 [inline] RIP: 0010:put_page+0x21/0x280 include/linux/mm.h:1553 Code: 90 90 90 90 90 90 90 90 90 41 54 55 53 48 89 fb e8 d4 d7 a2 f8 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 20 02 00 00 4c 8b 63 08 31 ff 4c 89 e5 83 e5 01 RSP: 0018:ffffc900005f8428 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff88f7ff98 RDX: 0000000000000001 RSI: ffffffff88f677ec RDI: 0000000000000008 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000008 R12: ffff88806bffd180 R13: ffff8880786fa240 R14: ffff8880786fa270 R15: 0000000000000007 FS: 0000000000000000(0000) GS:ffff88802b700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020005000 CR3: 0000000026970000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: skb_page_unref include/linux/skbuff_ref.h:43 [inline] __skb_frag_unref include/linux/skbuff_ref.h:56 [inline] skb_release_data+0x4d7/0x730 net/core/skbuff.c:1119 skb_release_all net/core/skbuff.c:1190 [inline] __kfree_skb+0x4f/0x70 net/core/skbuff.c:1204 tcp_wmem_free_skb include/net/tcp.h:306 [inline] tcp_rtx_queue_unlink_and_free include/net/tcp.h:2091 [inline] tcp_clean_rtx_queue net/ipv4/tcp_input.c:3436 [inline] tcp_ack+0x1eb7/0x5ba0 net/ipv4/tcp_input.c:4032 tcp_rcv_state_process+0xdd4/0x4c40 net/ipv4/tcp_input.c:6805 tcp_v4_do_rcv+0x1ad/0xa90 net/ipv4/tcp_ipv4.c:1939 tcp_v4_rcv+0x33b4/0x43a0 net/ipv4/tcp_ipv4.c:2351 ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x316/0x570 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:460 [inline] ip_rcv_finish net/ipv4/ip_input.c:447 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_rcv+0x2c3/0x5d0 net/ipv4/ip_input.c:567 __netif_receive_skb_one_core+0x199/0x1e0 net/core/dev.c:5672 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5785 process_backlog+0x443/0x15f0 net/core/dev.c:6117 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6883 napi_poll net/core/dev.c:6952 [inline] net_rx_action+0xa94/0x1010 net/core/dev.c:7074 handle_softirqs+0x213/0x8f0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xc/0x70 kernel/kcov.c:217 Code: cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 48 8b 15 74 8a 6a 7e <65> 8b 05 75 8a 6a 7e a9 00 01 ff 00 48 8b 34 24 74 1d f6 c4 01 74 RSP: 0018:ffffc90006c2fad0 EFLAGS: 00000286 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffffffff850b01f9 RDX: ffff888025244880 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000000 R12: 0000000000001000 R13: 00000000ffffffff R14: 00000000ffffffff R15: dffffc0000000000 n_tty_receive_buf_common+0xf96/0x18e0 drivers/tty/n_tty.c:1727 tty_ldisc_receive_buf+0xa2/0x190 drivers/tty/tty_buffer.c:387 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x264/0x780 drivers/tty/tty_buffer.c:495 process_one_work+0x958/0x1b30 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:_compound_head include/linux/page-flags.h:242 [inline] RIP: 0010:put_page+0x21/0x280 include/linux/mm.h:1553 Code: 90 90 90 90 90 90 90 90 90 41 54 55 53 48 89 fb e8 d4 d7 a2 f8 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 20 02 00 00 4c 8b 63 08 31 ff 4c 89 e5 83 e5 01 RSP: 0018:ffffc900005f8428 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff88f7ff98 RDX: 0000000000000001 RSI: ffffffff88f677ec RDI: 0000000000000008 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000008 R12: ffff88806bffd180 R13: ffff8880786fa240 R14: ffff8880786fa270 R15: 0000000000000007 FS: 0000000000000000(0000) GS:ffff88802b700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020005000 CR3: 0000000026970000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 90 nop 1: 90 nop 2: 90 nop 3: 90 nop 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 90 nop 9: 41 54 push %r12 b: 55 push %rbp c: 53 push %rbx d: 48 89 fb mov %rdi,%rbx 10: e8 d4 d7 a2 f8 call 0xf8a2d7e9 15: 48 8d 7b 08 lea 0x8(%rbx),%rdi 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 20: fc ff df 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2e: 0f 85 20 02 00 00 jne 0x254 34: 4c 8b 63 08 mov 0x8(%rbx),%r12 38: 31 ff xor %edi,%edi 3a: 4c 89 e5 mov %r12,%rbp 3d: 83 e5 01 and $0x1,%ebp