------------[ cut here ]------------ refcount_t: increment on 0; use-after-free. WARNING: CPU: 1 PID: 8514 at lib/refcount.c:156 refcount_inc_checked+0x4b/0x50 lib/refcount.c:156 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 8514 Comm: syz-executor.3 Not tainted 5.4.0-rc6+ #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+0x1fb/0x318 lib/dump_stack.c:118 panic+0x264/0x7a9 kernel/panic.c:221 __warn+0x20e/0x210 kernel/panic.c:582 report_bug+0x1b6/0x2f0 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:179 [inline] do_error_trap+0xd7/0x440 arch/x86/kernel/traps.c:272 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028 RIP: 0010:refcount_inc_checked+0x4b/0x50 lib/refcount.c:156 Code: 3d f7 ab 75 05 01 75 08 e8 12 e2 2d fe 5b 5d c3 e8 0a e2 2d fe c6 05 e1 ab 75 05 01 48 c7 c7 b4 c5 40 88 31 c0 e8 a5 78 00 fe <0f> 0b eb df 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 10 RSP: 0018:ffff8880816dfd10 EFLAGS: 00010246 RAX: 8358cd98639ffe00 RBX: ffff8880975b50f0 RCX: ffff8880a4010540 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: ffff8880816dfd18 R08: ffffffff815ca054 R09: ffffed1015d640d2 R10: ffffed1015d640d2 R11: 0000000000000000 R12: ffff88808e820588 R13: dffffc0000000000 R14: ffff88808e820000 R15: 1ffff11011d04047 j1939_netdev_start+0x47c/0x730 net/can/j1939/main.c:267 j1939_sk_bind+0x2c0/0xac0 net/can/j1939/socket.c:438 __sys_bind+0x2c2/0x3a0 net/socket.c:1647 __do_sys_bind net/socket.c:1658 [inline] __se_sys_bind net/socket.c:1656 [inline] __x64_sys_bind+0x7a/0x90 net/socket.c:1656 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290 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:00007efc734cbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a219 RDX: 0000000000000018 RSI: 0000000020000240 RDI: 0000000000000005 RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007efc734cc6d4 R13: 00000000004c057e R14: 00000000004d2c50 R15: 00000000ffffffff Kernel Offset: disabled Rebooting in 86400 seconds..