bisecting fixing commit since 4dd58158254c8a027f2bf5060b72ef64cafa3b9d
building syzkaller on d797d2018f9550530c469ce03b5ae36cfa1ebd23
testing commit 4dd58158254c8a027f2bf5060b72ef64cafa3b9d with gcc (GCC) 8.1.0
kernel signature: 5ac5d04377d08f438c9a9f54173c7221ace89db16138e10efaf9649362a4fd66
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: KASAN: null-ptr-deref Read in llcp_sock_getname
run #3: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #4: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #5: crashed: BUG: unable to handle kernel NULL pointer dereference in llcp_sock_getname
run #6: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #7: crashed: KASAN: null-ptr-deref Read 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
testing current HEAD 0bf999f9c5e74c7ecf9dafb527146601e5c848b9
testing commit 0bf999f9c5e74c7ecf9dafb527146601e5c848b9 with gcc (GCC) 8.1.0
kernel signature: 3dcc1fb090c1ba7addb42b4ecf4408532e5a7269e185fd4acd9719b4160fa819
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: KASAN: null-ptr-deref Read in llcp_sock_getname
run #3: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #4: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #5: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #6: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #7: crashed: BUG: unable to handle kernel NULL pointer dereference in llcp_sock_getname
run #8: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
run #9: crashed: BUG: unable to handle kernel NULL pointer dereference in llcp_sock_getname
revisions tested: 2, total time: 20m33.056096672s (build: 12m39.433429009s, test: 7m4.772008324s)
the crash still happens on HEAD
commit msg: linux/pipe_fs_i.h: fix kernel-doc warnings after @wait was split
crash: BUG: unable to handle kernel NULL pointer dereference in llcp_sock_getname
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 94e05067 P4D 94e05067 PUD 9f0e7067 PMD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8554 Comm: syz-executor.4 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:memcpy_erms+0x6/0x10 arch/x86/lib/memcpy_64.S:56
Code: cc cc cc cc eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 <f3> a4 c3 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe
RSP: 0018:ffff88808d0afcf0 EFLAGS: 00010246
RAX: ffff88808d0afe12 RBX: 0000000000000001 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88808d0afe12
RBP: ffff88808d0afd10 R08: ffffed1011a15fc3 R09: ffffed1011a15fc3
R10: ffffed1011a15fc2 R11: ffff88808d0afe12 R12: ffff88808d0afe12
R13: 0000000000000000 R14: ffff8880761f0a80 R15: 0000000000000000
FS:  00007fc757763700(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000091772000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 memcpy include/linux/string.h:381 [inline]
 llcp_sock_getname+0x341/0x440 net/nfc/llcp_sock.c:519
 __sys_getpeername+0x123/0x220 net/socket.c:1946
 __do_sys_getpeername net/socket.c:1959 [inline]
 __se_sys_getpeername net/socket.c:1956 [inline]
 __x64_sys_getpeername+0x6e/0xb0 net/socket.c:1956
 do_syscall_64+0xca/0x5f0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a219
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc757762c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000034
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a219
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc7577636d4
R13: 00000000004c0f29 R14: 00000000004d3dd8 R15: 00000000ffffffff
Modules linked in:
CR2: 0000000000000000