syzbot has found a reproducer for the following issue on: HEAD commit: 6ac6dc746d70 Merge branch 'mlx5-next' of git://git.kernel... git tree: net-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=15095107f00000 kernel config: https://syzkaller.appspot.com/x/.config?x=20ac3e0ebf0db3bd dashboard link: https://syzkaller.appspot.com/bug?extid=92968395eedbdbd3617d 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=12e777bff00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12613a87f00000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+92968395eedbdbd3617d@xxxxxxxxxxxxxxxxxxxxxxxxx general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 PID: 11 Comm: kworker/u4:1 Not tainted 5.19.0-rc1-syzkaller-00373-g6ac6dc746d70 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:__list_del_entry_valid+0x81/0xf0 lib/list_debug.c:51 Code: 0f 84 b5 a6 41 05 48 b8 22 01 00 00 00 00 ad de 49 39 c4 0f 84 b6 a6 41 05 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 75 51 49 8b 14 24 48 39 ea 0f 85 6a a6 41 05 49 8d 7d RSP: 0018:ffffc90000107bc0 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88801759b310 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff879e16e1 RDI: ffff88801759b328 RBP: ffff88801759b320 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: ffff88801759b328 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5555f6a01d CR3: 0000000074e46000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __list_del_entry include/linux/list.h:134 [inline] list_del include/linux/list.h:148 [inline] cttimeout_net_exit+0x211/0x540 net/netfilter/nfnetlink_cttimeout.c:618 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:162 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__list_del_entry_valid+0x81/0xf0 lib/list_debug.c:51 Code: 0f 84 b5 a6 41 05 48 b8 22 01 00 00 00 00 ad de 49 39 c4 0f 84 b6 a6 41 05 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 75 51 49 8b 14 24 48 39 ea 0f 85 6a a6 41 05 49 8d 7d RSP: 0018:ffffc90000107bc0 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88801759b310 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff879e16e1 RDI: ffff88801759b328 RBP: ffff88801759b320 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: ffff88801759b328 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5555f6a01d CR3: 0000000025f1e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 0f 84 b5 a6 41 05 je 0x541a6bb 6: 48 b8 22 01 00 00 00 movabs $0xdead000000000122,%rax d: 00 ad de 10: 49 39 c4 cmp %rax,%r12 13: 0f 84 b6 a6 41 05 je 0x541a6cf 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 20: fc ff df 23: 4c 89 e2 mov %r12,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2e: 75 51 jne 0x81 30: 49 8b 14 24 mov (%r12),%rdx 34: 48 39 ea cmp %rbp,%rdx 37: 0f 85 6a a6 41 05 jne 0x541a6a7 3d: 49 rex.WB 3e: 8d .byte 0x8d 3f: 7d .byte 0x7d
