bisecting fixing commit since a844dc4c544291470aa69edbe2434b040794e269
building syzkaller on 1508f45368a309a3b1196a342b3d64ce7be4cc43
testing commit a844dc4c544291470aa69edbe2434b040794e269 with gcc (GCC) 8.1.0
kernel signature: 316c09f9c583e8de18ebdc204a7fba6714d6ab2f8ea7a27cda84c2cedcb861d4
all runs: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
testing current HEAD 98db2bf27b9ed2d5ed0b6c9c8a4bfcb127a19796
testing commit 98db2bf27b9ed2d5ed0b6c9c8a4bfcb127a19796 with gcc (GCC) 8.1.0
kernel signature: cdb29bbd79cb1c12d4bc4a428c99e668597f9bcbc1e6adfa4f37f11992582113
all runs: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
revisions tested: 2, total time: 25m31.476198251s (build: 16m54.053553141s, test: 7m39.653682399s)
the crash still happens on HEAD
commit msg: Linux 4.14.171
crash: KASAN: null-ptr-deref Read in llcp_sock_getname
IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready
IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready
==================================================================
team0: Port device team_slave_0 added
BUG: KASAN: null-ptr-deref in memcpy include/linux/string.h:347 [inline]
BUG: KASAN: null-ptr-deref in llcp_sock_getname+0x378/0x480 net/nfc/llcp_sock.c:532
Read of size 43 at addr           (null) by task syz-executor.0/7072

CPU: 1 PID: 7072 Comm: syz-executor.0 Not tainted 4.14.171-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xf7/0x13b lib/dump_stack.c:58
 kasan_report_error mm/kasan/report.c:349 [inline]
 kasan_report.cold.8+0x6d/0x2d3 mm/kasan/report.c:409
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 memcpy+0x23/0x50 mm/kasan/kasan.c:302
 memcpy include/linux/string.h:347 [inline]
 llcp_sock_getname+0x378/0x480 net/nfc/llcp_sock.c:532
 SYSC_getpeername+0x122/0x250 net/socket.c:1715
8021q: adding VLAN 0 to HW filter on device bond0
 SyS_getpeername+0x9/0x10 net/socket.c:1699
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45a6f9
RSP: 002b:00007fee3033cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000034
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a6f9
IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fee3033d6d4
R13: 00000000004c1430 R14: 00000000004d5658 R15: 00000000ffffffff
==================================================================
8021q: adding VLAN 0 to HW filter on device team0