Hello, syzbot found the following issue on: HEAD commit: 7366c23ff492 ptp: dp83640: don't define PAGE0 git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=15af7951300000 kernel config: https://syzkaller.appspot.com/x/.config?x=c31c0936547df9ea dashboard link: https://syzkaller.appspot.com/bug?extid=df709157a4ecaf192b03 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12f2b28d300000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1656e7c7300000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+df709157a4ecaf192b03@xxxxxxxxxxxxxxxxxxxxxxxxx general protection fault, probably for non-canonical address 0xdffffc0000000182: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000c10-0x0000000000000c17] CPU: 0 PID: 10393 Comm: syz-executor023 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__ref_is_percpu include/linux/percpu-refcount.h:174 [inline] RIP: 0010:percpu_ref_put_many include/linux/percpu-refcount.h:319 [inline] RIP: 0010:percpu_ref_put include/linux/percpu-refcount.h:338 [inline] RIP: 0010:cgroup_bpf_put include/linux/cgroup.h:926 [inline] RIP: 0010:cgroup_sk_free+0x8d/0x570 kernel/cgroup/cgroup.c:6613 Code: 0e 06 00 40 84 ed 5a 0f 84 42 01 00 00 e8 0b 08 06 00 4c 8d ab 10 0c 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <80> 3c 02 00 0f 85 6f 04 00 00 48 8b ab 10 0c 00 00 31 ff 49 89 ec RSP: 0018:ffffc9000cef79c0 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000182 RSI: ffffffff81700755 RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff81700746 R11: 0000000000000000 R12: ffff888017463000 R13: 0000000000000c10 R14: ffffffff8d0d318c R15: ffff888017463060 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000080 CR3: 000000000b68e000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: sk_prot_free net/core/sock.c:1852 [inline] __sk_destruct+0x579/0x900 net/core/sock.c:1943 sk_destruct+0xbd/0xe0 net/core/sock.c:1958 __sk_free+0xef/0x3d0 net/core/sock.c:1969 sk_free+0x78/0xa0 net/core/sock.c:1980 sock_put include/net/sock.h:1815 [inline] nr_release+0x392/0x450 net/netrom/af_netrom.c:554 __sock_release+0xcd/0x280 net/socket.c:649 sock_close+0x18/0x20 net/socket.c:1314 __fput+0x288/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xbae/0x2a30 kernel/exit.c:825 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2868 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x443559 Code: Unable to access opcode bytes at RIP 0x44352f. RSP: 002b:00007fff3922f8c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002b RAX: 0000000000000003 RBX: 0000000000000003 RCX: 0000000000443559 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000003 R08: 000000000000000d R09: 000000000000000d R10: 000000000000000d R11: 0000000000000246 R12: 00000000009db2c0 R13: 0000000000000000 R14: 00000000004b8018 R15: 00000000004004b8 Modules linked in: ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 00 40 84 add %al,-0x7c(%rax) 3: ed in (%dx),%eax 4: 5a pop %rdx 5: 0f 84 42 01 00 00 je 0x14d b: e8 0b 08 06 00 callq 0x6081b 10: 4c 8d ab 10 0c 00 00 lea 0xc10(%rbx),%r13 17: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1e: fc ff df 21: 4c 89 ea mov %r13,%rdx 24: 48 c1 ea 03 shr $0x3,%rdx * 28: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2c: 0f 85 6f 04 00 00 jne 0x4a1 32: 48 8b ab 10 0c 00 00 mov 0xc10(%rbx),%rbp 39: 31 ff xor %edi,%edi 3b: 49 89 ec mov %rbp,%r12 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches