Hello, syzbot found the following issue on: HEAD commit: e0bfcf9c77d9 Merge tag 'mlx5-fixes-2021-10-20' of git://gi.. git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=17900a0cb00000 kernel config: https://syzkaller.appspot.com/x/.config?x=bab9d35f204746a7 dashboard link: https://syzkaller.appspot.com/bug?extid=1dca817d274a3fb19f2b 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=144d76b4b00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14732b80b00000 Bisection is inconclusive: the issue happens on the oldest tested release. bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14093652b00000 final oops: https://syzkaller.appspot.com/x/report.txt?x=16093652b00000 console output: https://syzkaller.appspot.com/x/log.txt?x=12093652b00000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+1dca817d274a3fb19f2b(a)syzkaller.appspotmail.com R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ------------[ cut here ]------------ ODEBUG: assert_init not available (active state 0) object type: timer_list hint: 0x0 WARNING: CPU: 0 PID: 6548 at lib/debugobjects.c:505 debug_print_object+0x16e/0x250 lib/debugobjects.c:505 Modules linked in: CPU: 0 PID: 6548 Comm: syz-executor286 Not tainted 5.15.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:505 Code: ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 af 00 00 00 48 8b 14 dd 80 3e e4 89 4c 89 ee 48 c7 c7 80 32 e4 89 e8 5e 1d 15 05 <0f> 0b 83 05 d5 39 90 09 01 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e c3 RSP: 0018:ffffc90002d7ecc0 EFLAGS: 00010086 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000000000 RDX: ffff8880163c8000 RSI: ffffffff815e88a8 RDI: fffff520005afd8a RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815e264e R11: 0000000000000000 R12: ffffffff898de560 R13: ffffffff89e43900 R14: ffffffff81658550 R15: 1ffff920005afda3 FS: 0000555555c03300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fef3003e098 CR3: 0000000073ad0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_object_assert_init lib/debugobjects.c:895 [inline] debug_object_assert_init+0x1f4/0x2e0 lib/debugobjects.c:866 debug_timer_assert_init kernel/time/timer.c:739 [inline] debug_assert_init kernel/time/timer.c:784 [inline] del_timer+0x6d/0x110 kernel/time/timer.c:1204 try_to_grab_pending+0x6d/0xd0 kernel/workqueue.c:1270 __cancel_work_timer+0xa6/0x570 kernel/workqueue.c:3129 batadv_nc_mesh_free+0x41/0x120 net/batman-adv/network-coding.c:1869 batadv_mesh_free+0x7d/0x170 net/batman-adv/main.c:245 batadv_mesh_init+0x62f/0x710 net/batman-adv/main.c:226 batadv_softif_init_late+0xad4/0xdd0 net/batman-adv/soft-interface.c:804 register_netdevice+0x51e/0x1500 net/core/dev.c:10229 batadv_softif_newlink+0x6e/0x90 net/batman-adv/soft-interface.c:1068 __rtnl_newlink+0x106d/0x1750 net/core/rtnetlink.c:3458 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3506 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5572 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2510 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1935 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f14439a87e9 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffda1fa6268 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f14439a87e9 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003 RBP: 00007ffda1fa6270 R08: 0000000000000002 R09: 00007f1443003531 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 --- 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(a)googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches