bisecting fixing commit since ddef1e8e3f6eb26034833b7255e3fa584d54a230
building syzkaller on 5ea87a6638e52a94361b26b8576a1605585815fb
testing commit ddef1e8e3f6eb26034833b7255e3fa584d54a230 with gcc (GCC) 8.1.0
kernel signature: 1585f24f239bc521fd4cb37b9e56efa1ad8e660e02a77e0e7462d1dc4aeec3a1
run #0: crashed: BUG: unable to handle kernel NULL pointer dereference in corrupted
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 corrupted
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 in llcp_sock_getname
run #9: crashed: BUG: unable to handle kernel NULL pointer dereference in corrupted
testing current HEAD c6db52a88798e5a0dfef80041ad4d33cc8cf04eb
testing commit c6db52a88798e5a0dfef80041ad4d33cc8cf04eb with gcc (GCC) 8.1.0
kernel signature: f30efc36136addcc239bb746751a7539c928d94e58046496169c72f478af6c15
all runs: crashed: KASAN: null-ptr-deref Read in llcp_sock_getname
revisions tested: 2, total time: 23m59.182246308s (build: 16m57.383857235s, test: 6m17.624279361s)
the crash still happens on HEAD
commit msg: Linux 4.14.183
crash: KASAN: null-ptr-deref Read in llcp_sock_getname
IPv6: ADDRCONF(NETDEV_UP): hsr0: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready
8021q: adding VLAN 0 to HW filter on device batadv0
==================================================================
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.0/7214

CPU: 1 PID: 7214 Comm: syz-executor.0 Not tainted 4.14.183-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
BUG: unable to handle kernel NULL pointer dereference
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xf7/0x13b lib/dump_stack.c:58
 at           (null)
IP: memcpy_erms+0x6/0x10 arch/x86/lib/memcpy_64.S:54
PGD 8eeb7067 
 kasan_report_error mm/kasan/report.c:349 [inline]
 kasan_report.cold.8+0x6d/0x2d3 mm/kasan/report.c:409
P4D 8eeb7067 
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
PUD 8ea74067 
 memcpy+0x23/0x50 mm/kasan/kasan.c:302
PMD 0 
 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
Oops: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 7220 Comm: syz-executor.3 Not tainted 4.14.183-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88808de00040 task.stack: ffff888082ea0000
RIP: 0010:memcpy_erms+0x6/0x10 arch/x86/lib/memcpy_64.S:54
 SyS_getpeername+0x9/0x10 net/socket.c:1699
RSP: 0018:ffff888082ea7cb8 EFLAGS: 00010246
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
RAX: ffff888082ea7e22 RBX: 000000000000002b RCX: 000000000000002b
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RDX: 000000000000002b RSI: 0000000000000000 RDI: ffff888082ea7e22
RIP: 0033:0x459f49
RBP: ffff888082ea7cd8 R08: ffffed10105d4fca R09: ffffed10105d4fc4
RSP: 002b:00007f710ea62c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000034
R10: ffffed10105d4fc9 R11: ffff888082ea7e4c R12: ffff888082ea7e22
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459f49
R13: 0000000000000000 R14: ffff88808dd05ad0 R15: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
FS:  00007fd7fcc15700(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f710ea636d4
CR2: 0000000000000000 CR3: 000000008eeb6000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
R13: 00000000004c0bf0 R14: 00000000004d37a8 R15: 00000000ffffffff
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
==================================================================
Call Trace: