kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 1 PID: 16290 Comm: syz-executor.1 Not tainted 4.14.305-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 task: ffff888082c2c200 task.stack: ffff8880af540000 RIP: 0010:__read_once_size include/linux/compiler.h:185 [inline] RIP: 0010:sk_dst_get include/net/sock.h:1772 [inline] RIP: 0010:pppol2tp_session_init+0x1ca/0x4d0 net/l2tp/l2tp_ppp.c:607 RSP: 0018:ffff8880af547c50 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8880a8394900 RCX: ffffc900070d4000 RDX: 0000000000000045 RSI: ffffffff8686f872 RDI: 0000000000000228 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000020011 R10: ffff888082c2cab0 R11: ffff888082c2c200 R12: 0000000000003fa2 R13: 0000000000000002 R14: ffff8880b3f172d2 R15: ffff8880b3f172f0 FS: 00007f3cfb565700(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30c24000 CR3: 0000000099e42000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pppol2tp_connect+0xd5c/0x13d0 net/l2tp/l2tp_ppp.c:781 SYSC_connect net/socket.c:1655 [inline] SyS_connect+0x1f4/0x240 net/socket.c:1636 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 RIP: 0033:0x7f3cfcff30f9 RSP: 002b:00007f3cfb565168 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 00007f3cfd112f80 RCX: 00007f3cfcff30f9 RDX: 000000000000002e RSI: 0000000020000000 RDI: 0000000000000007 RBP: 00007f3cfd04eae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffff874d34f R14: 00007f3cfb565300 R15: 0000000000022000 Code: fa 80 3d 16 77 6c 03 00 0f 84 25 02 00 00 e8 3e 5e ce fa 48 8d bd 28 02 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 db 02 00 00 48 8b ad 28 02 00 00 e8 40 3b bf RIP: __read_once_size include/linux/compiler.h:185 [inline] RSP: ffff8880af547c50 RIP: sk_dst_get include/net/sock.h:1772 [inline] RSP: ffff8880af547c50 RIP: pppol2tp_session_init+0x1ca/0x4d0 net/l2tp/l2tp_ppp.c:607 RSP: ffff8880af547c50 ---[ end trace c49329a5eb530035 ]--- ---------------- Code disassembly (best guess): 0: fa cli 1: 80 3d 16 77 6c 03 00 cmpb $0x0,0x36c7716(%rip) # 0x36c771e 8: 0f 84 25 02 00 00 je 0x233 e: e8 3e 5e ce fa callq 0xface5e51 13: 48 8d bd 28 02 00 00 lea 0x228(%rbp),%rdi 1a: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 21: fc ff df 24: 48 89 fa mov %rdi,%rdx 27: 48 c1 ea 03 shr $0x3,%rdx * 2b: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2f: 0f 85 db 02 00 00 jne 0x310 35: 48 8b ad 28 02 00 00 mov 0x228(%rbp),%rbp 3c: e8 .byte 0xe8 3d: 40 rex 3e: 3b .byte 0x3b 3f: bf .byte 0xbf