ISOFS: Invalid session number
ISOFS: Unable to identify CD-ROM format.
bpfilter: read fail -512

=============================
WARNING: suspicious RCU usage
4.19.0-rc2+ #221 Not tainted
-----------------------------
kernel/pid.c:330 suspicious rcu_dereference_check() usage!
ISOFS: Invalid session number or type of track

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor6/4311:
 #0: 
ISOFS: Invalid session number or type of track
00000000ccf0cfc9 (bpfilter_lock){+.+.}, at: __bpfilter_process_sockopt+0x1c5/0x39b net/bpfilter/bpfilter_kern.c:64

stack backtrace:
ISOFS: Invalid session number
CPU: 0 PID: 4311 Comm: syz-executor6 Not tainted 4.19.0-rc2+ #221
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
ISOFS: Invalid session number
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 lockdep_rcu_suspicious+0x14a/0x153 kernel/locking/lockdep.c:4537
 pid_task+0x1ce/0x200 kernel/pid.c:329
 shutdown_umh.constprop.0+0x33/0x7c net/bpfilter/bpfilter_kern.c:26
 __stop_umh net/bpfilter/bpfilter_kern.c:38 [inline]
 __bpfilter_process_sockopt.cold.1+0x9b/0xa0 net/bpfilter/bpfilter_kern.c:78
 bpfilter_mbox_request+0x4d/0xb0 net/ipv4/bpfilter/sockopt.c:25
 bpfilter_ip_get_sockopt+0x6b/0x90 net/ipv4/bpfilter/sockopt.c:42
 ip_getsockopt+0x247/0x2b0 net/ipv4/ip_sockglue.c:1566
 udp_getsockopt+0x62/0xa0 net/ipv4/udp.c:2574
 sock_common_getsockopt+0x9a/0xe0 net/core/sock.c:2997
ISOFS: Unable to identify CD-ROM format.
 __sys_getsockopt+0x1ad/0x390 net/socket.c:1937
ISOFS: Unable to identify CD-ROM format.
 __do_sys_getsockopt net/socket.c:1948 [inline]
 __se_sys_getsockopt net/socket.c:1945 [inline]
 __x64_sys_getsockopt+0xbe/0x150 net/socket.c:1945
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: fd b4 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 b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f1e64b6ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 00007f1e64b6b6d4 RCX: 0000000000457099
RDX: 0000000000000041 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000009300a0 R08: 0000000020000000 R09: 0000000000000000
R10: 0000000020000080 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004cc550 R14: 00000000004c384d R15: 0000000000000000
ISOFS: Invalid session number or type of track
ISOFS: Invalid session number or type of track
ISOFS: Invalid session number
ISOFS: Invalid session number
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.