On Sat, Jul 17, 2021 at 10:02:20AM -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 7fef2edf7cc7 sd: don't mess with SD_MINORS for CONFIG_DEBU.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=147c3b3c300000 > kernel config: https://syzkaller.appspot.com/x/.config?x=957eaf08bd3bb8d6 > dashboard link: https://syzkaller.appspot.com/bug?extid=3405f46cf7078134383e > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+3405f46cf7078134383e@xxxxxxxxxxxxxxxxxxxxxxxxx > > bond0 (unregistering): (slave bond_slave_0): Releasing backup interface > bond0 (unregistering): Released all slaves > ------------[ cut here ]------------ > name 'use-gss-proxy' > WARNING: CPU: 0 PID: 7951 at fs/proc/generic.c:709 remove_proc_entry+0x389/0x460 fs/proc/generic.c:709 I'm probably missing something obvious. This says we're calling remove_proc_entry on a name that doesn't exist. We're doing that removal from a pernet_operations ->exit method. As I understand, those won't get called unless the corresponding ->init succeeds, but that means the proc entry was created. There's a bug in gss_svc_init_net that has an extra unnecessary call, but I'm not seeing how we hit that case there either. Hm. --b. > Modules linked in: > CPU: 0 PID: 7951 Comm: kworker/u4:2 Tainted: G W 5.14.0-rc1-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Workqueue: netns cleanup_net > RIP: 0010:remove_proc_entry+0x389/0x460 fs/proc/generic.c:709 > Code: e9 6d fe ff ff e8 f7 d9 85 ff 48 c7 c7 20 d4 b3 8b e8 fb 96 3d 07 e8 e6 d9 85 ff 4c 89 e6 48 c7 c7 00 2a 9c 89 e8 92 86 f8 06 <0f> 0b e9 a4 fe ff ff e8 cb d9 85 ff 48 8d bd d8 00 00 00 48 b8 00 > RSP: 0018:ffffc9000c8efb48 EFLAGS: 00010286 > RAX: 0000000000000000 RBX: 1ffff9200191df6b RCX: 0000000000000000 > RDX: ffff8880341121c0 RSI: ffffffff815c9ca5 RDI: fffff5200191df5b > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 > R10: ffffffff815c3aae R11: 0000000000000000 R12: ffffffff8aa28e40 > R13: dffffc0000000000 R14: ffff888000102000 R15: 0000000000000001 > FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f38761a8740 CR3: 000000002c23a000 CR4: 00000000001506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 > Call Trace: > destroy_use_gss_proxy_proc_entry net/sunrpc/auth_gss/svcauth_gss.c:1504 [inline] > gss_svc_shutdown_net+0x196/0x8c0 net/sunrpc/auth_gss/svcauth_gss.c:1992 > ops_exit_list+0xb0/0x160 net/core/net_namespace.c:175 > cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:595 > process_one_work+0x98d/0x1630 kernel/workqueue.c:2276 > worker_thread+0x658/0x11f0 kernel/workqueue.c:2422 > kthread+0x3e5/0x4d0 kernel/kthread.c:319 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 > > > --- > 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.