BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 76493067 P4D 76493067 PUD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 3626 Comm: syz-executor.3 Not tainted 5.18.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc90000007a60 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff888037972f90 RCX: 0000000000000100 RDX: 1ffff11006f2e5f3 RSI: ffff888023c66e00 RDI: ffff888038a14540 RBP: ffff888038a14540 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff87d59c97 R11: 0000000000000000 R12: ffff888023c66e00 R13: 0000000000000000 R14: ffff888038a14ca0 R15: ffff888078cb812c FS: 00005555573e5400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000004175e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __tcp_transmit_skb+0x1098/0x38b0 net/ipv4/tcp_output.c:1372 tcp_transmit_skb net/ipv4/tcp_output.c:1421 [inline] tcp_xmit_probe_skb+0x28c/0x320 net/ipv4/tcp_output.c:4010 tcp_write_wakeup+0x1bd/0x610 net/ipv4/tcp_output.c:4063 tcp_send_probe0+0x44/0x560 net/ipv4/tcp_output.c:4078 tcp_probe_timer net/ipv4/tcp_timer.c:398 [inline] tcp_write_timer_handler+0x9ed/0xbc0 net/ipv4/tcp_timer.c:626 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:642 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1750 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode+0x0/0x40 kernel/kcov.c:166 Code: 48 89 df e8 22 fb 4a 00 e9 59 fe ff ff 48 8b 7c 24 08 e8 13 fb 4a 00 e9 61 fd ff ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc <65> 8b 05 d9 fe 89 7e 89 c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 RSP: 0018:ffffc9000314f758 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 8000000041725007 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff8880430da100 RDI: 0000000000000003 RBP: 1ffff92000629eee R08: 0000000000000000 R09: ffff88803e04a843 R10: ffffffff81afc8e8 R11: 0000000000000000 R12: ffff88801f0c2358 R13: 00007fe488bd4000 R14: 8000000041725007 R15: 0000000000000000 write_comp_data kernel/kcov.c:221 [inline] __sanitizer_cov_trace_const_cmp4+0x1c/0x70 kernel/kcov.c:287 vm_normal_page+0xc8/0x2a0 mm/memory.c:615 copy_present_pte mm/memory.c:946 [inline] copy_pte_range mm/memory.c:1071 [inline] copy_pmd_range mm/memory.c:1157 [inline] copy_pud_range mm/memory.c:1194 [inline] copy_p4d_range mm/memory.c:1218 [inline] copy_page_range+0xd0f/0x3e50 mm/memory.c:1291 dup_mmap kernel/fork.c:701 [inline] dup_mm+0xa4e/0x13d0 kernel/fork.c:1521 copy_mm kernel/fork.c:1573 [inline] copy_process+0x3b14/0x6fe0 kernel/fork.c:2234 kernel_clone+0xe7/0xab0 kernel/fork.c:2639 __do_sys_clone+0xc8/0x110 kernel/fork.c:2756 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: 0033:0x7fe4892876db Code: ed 0f 85 60 01 00 00 64 4c 8b 0c 25 10 00 00 00 45 31 c0 4d 8d 91 d0 02 00 00 31 d2 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 89 00 00 00 41 89 c5 85 c0 0f 85 90 00 00 RSP: 002b:00007ffc678cf680 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe4892876db RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 00005555573e5400 R10: 00005555573e56d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffc678cf760 Modules linked in: CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc90000007a60 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff888037972f90 RCX: 0000000000000100 RDX: 1ffff11006f2e5f3 RSI: ffff888023c66e00 RDI: ffff888038a14540 RBP: ffff888038a14540 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff87d59c97 R11: 0000000000000000 R12: ffff888023c66e00 R13: 0000000000000000 R14: ffff888038a14ca0 R15: ffff888078cb812c FS: 00005555573e5400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000004175e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 48 89 df mov %rbx,%rdi 3: e8 22 fb 4a 00 callq 0x4afb2a 8: e9 59 fe ff ff jmpq 0xfffffe66 d: 48 8b 7c 24 08 mov 0x8(%rsp),%rdi 12: e8 13 fb 4a 00 callq 0x4afb2a 17: e9 61 fd ff ff jmpq 0xfffffd7d 1c: cc int3 1d: cc int3 1e: cc int3 1f: cc int3 20: cc int3 21: cc int3 22: cc int3 23: cc int3 24: cc int3 25: cc int3 26: cc int3 27: cc int3 28: cc int3 29: cc int3 * 2a: 65 8b 05 d9 fe 89 7e mov %gs:0x7e89fed9(%rip),%eax # 0x7e89ff0a <-- trapping instruction 31: 89 c2 mov %eax,%edx 33: 81 e2 00 01 00 00 and $0x100,%edx 39: a9 00 01 ff 00 test $0xff0100,%eax 3e: 74 10 je 0x50