bisecting fixing commit since fa5941f45d7ed070118b7c209b7f2c3a034293bd
building syzkaller on 618456b4f4f74528ac6b9d709b1870d0e1d70eb2
testing commit fa5941f45d7ed070118b7c209b7f2c3a034293bd with gcc (GCC) 8.1.0
kernel signature: cec3d73f46cbecedf552089f5b320977adf628941c1220c24f5a59e84cfca444
run #0: crashed: WARNING: locking bug in inet_autobind
run #1: crashed: WARNING: locking bug in inet_autobind
run #2: crashed: WARNING: locking bug in inet_autobind
run #3: crashed: WARNING: locking bug in inet_autobind
run #4: crashed: WARNING: locking bug in inet_autobind
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
testing current HEAD b850307b279cbd12ab8c654d1a3dfe55319cc475
testing commit b850307b279cbd12ab8c654d1a3dfe55319cc475 with gcc (GCC) 8.1.0
kernel signature: 8ccb2153c7287b28d56db28cc31037c680a653c26f1ad2b574cb2a078c55263f
run #0: crashed: WARNING: locking bug in inet_autobind
run #1: crashed: general protection fault in pppol2tp_session_init
run #2: crashed: general protection fault in pppol2tp_session_init
run #3: crashed: WARNING: locking bug in inet_autobind
run #4: crashed: general protection fault in pppol2tp_session_init
run #5: crashed: general protection fault in pppol2tp_session_init
run #6: crashed: general protection fault in pppol2tp_session_init
run #7: crashed: general protection fault in pppol2tp_session_init
run #8: crashed: WARNING: locking bug in inet_autobind
run #9: crashed: general protection fault in pppol2tp_session_init
revisions tested: 2, total time: 32m58.188264179s (build: 16m44.552980503s, test: 14m46.540552522s)
the crash still happens on HEAD
commit msg: Linux 4.14.184
crash: general protection fault in pppol2tp_session_init
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: 1646 Comm: syz-executor.3 Not tainted 4.14.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88808dc58440 task.stack: ffff88808b640000
RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline]
RIP: 0010:sk_dst_get include/net/sock.h:1766 [inline]
RIP: 0010:pppol2tp_session_init+0x1c1/0x480 net/l2tp/l2tp_ppp.c:616
RSP: 0018:ffff88808b647b88 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88808aee5b00 RCX: 1ffffffff0ed33ad
RDX: 0000000000000045 RSI: ffffffff86bbfc40 RDI: 0000000000000228
RBP: ffff88808b647bb0 R08: ffff88808dc58d10 R09: 0000000000000000
R10: 0000000000000028 R11: ffff88808dc58440 R12: 0000000000000000
R13: 000000000000066e R14: ffff88808b647d28 R15: ffff8880a5764a40
FS:  00007f0b663fb700(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200001c0 CR3: 0000000097081000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 pppol2tp_connect+0xce4/0x1380 net/l2tp/l2tp_ppp.c:790
 SYSC_connect+0x1e5/0x2a0 net/socket.c:1655
 SyS_connect+0x9/0x10 net/socket.c:1636
 do_syscall_64+0x1c9/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x458da9
RSP: 002b:00007f0b663fac78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458da9
RDX: 0000000000000026 RSI: 0000000020000180 RDI: 0000000000000009
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0b663fb6d4
R13: 00000000004bf20b R14: 00000000004d02f0 R15: 00000000ffffffff
Code: 5a 85 c0 74 0d 80 3d 2e 92 9b 02 00 0f 84 11 02 00 00 49 8d bc 24 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 92 02 00 00 4d 8b b4 24 28 02 00 00 e8 78 57 
RIP: __read_once_size include/linux/compiler.h:183 [inline] RSP: ffff88808b647b88
RIP: sk_dst_get include/net/sock.h:1766 [inline] RSP: ffff88808b647b88
RIP: pppol2tp_session_init+0x1c1/0x480 net/l2tp/l2tp_ppp.c:616 RSP: ffff88808b647b88
---[ end trace 813f5b04f6526667 ]---