bisecting fixing commit since b98aebd298246df37b472c52a2ee1023256d02e3
building syzkaller on 25bb509e5964da8203766c4039e4fef25e4689b1
testing commit b98aebd298246df37b472c52a2ee1023256d02e3 with gcc (GCC) 8.1.0
kernel signature: 7e02b5a7caf8d388334b2dfc82726d84bd65f5505edd4e453cc1fb72deec01a8
run #0: crashed: KASAN: null-ptr-deref in llcp_sock_getname
run #1: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #2: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #3: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #4: crashed: BUG: unable to handle kernel NULL pointer dereference in corrupted
run #5: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #6: crashed: BUG: unable to handle kernel
run #7: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #8: crashed: BUG: unable to handle kernel
run #9: crashed: BUG: unable to handle kernel
testing current HEAD e0f8b8a65a473a8baa439cf865a694bbeb83fe90
testing commit e0f8b8a65a473a8baa439cf865a694bbeb83fe90 with gcc (GCC) 8.1.0
kernel signature: 4af913a4cea5aadfd746ccda3ddd8627d4e905230166ed66d086a051f982b922
run #0: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #1: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #2: crashed: BUG: unable to handle kernel
run #3: crashed: BUG: unable to handle kernel
run #4: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #5: crashed: BUG: unable to handle kernel
run #6: crashed: BUG: unable to handle kernel
run #7: crashed: KASAN: null-ptr-deref in llcp_sock_getname
run #8: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #9: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
revisions tested: 2, total time: 23m0.148795267s (build: 16m12.40574503s, test: 6m24.655515112s)
the crash still happens on HEAD
commit msg: Linux 4.14.170
crash: KASAN: null-ptr-deref Read in llcp_sock_getname
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bond: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_team: link becomes ready
==================================================================
IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready
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 3 at addr           (null) by task syz-executor.1/7118

IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready
CPU: 1 PID: 7118 Comm: syz-executor.1 Not tainted 4.14.170-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
 SyS_getpeername+0x9/0x10 net/socket.c:1699
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x459f39
RSP: 002b:00007f651c28bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000034
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459f39
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f651c28c6d4
R13: 00000000004c0bd0 R14: 00000000004d3668 R15: 00000000ffffffff
==================================================================
IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready