================================================================== BUG: KASAN: null-ptr-deref in atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] BUG: KASAN: null-ptr-deref in refcount_sub_and_test_checked+0x87/0x200 lib/refcount.c:182 Read of size 4 at addr 00000000000000c8 by task syz-executor.3/13414 CPU: 1 PID: 13414 Comm: syz-executor.3 Not tainted 5.3.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 __kasan_report.cold+0x5/0x36 mm/kasan/report.c:486 kasan_report+0x12/0x17 mm/kasan/common.c:618 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192 __kasan_check_read+0x11/0x20 mm/kasan/common.c:92 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] refcount_sub_and_test_checked+0x87/0x200 lib/refcount.c:182 refcount_dec_and_test_checked+0x1b/0x20 lib/refcount.c:220 x25_neigh_put include/net/x25.h:252 [inline] x25_connect+0x8de/0xed0 net/x25/af_x25.c:820 __sys_connect+0x264/0x330 net/socket.c:1828 __do_sys_connect net/socket.c:1839 [inline] __se_sys_connect net/socket.c:1836 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1836 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4598e9 Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa349c86c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004598e9 RDX: 0000000000000012 RSI: 0000000020000080 RDI: 0000000000000004 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa349c876d4 R13: 00000000004bff11 R14: 00000000004d1e48 R15: 00000000ffffffff ==================================================================