On Tue, Apr 21, 2020 at 12:46 PM syzbot <syzbot+21f82f61c24a7295edf5@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 39a314cd Add linux-next specific files for 20200421 > git tree: linux-next +linux-next, Stephen for a new linux-next breakage > console output: https://syzkaller.appspot.com/x/log.txt?x=127ede73e00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=8ef80c3f5d43f5bd > dashboard link: https://syzkaller.appspot.com/bug?extid=21f82f61c24a7295edf5 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+21f82f61c24a7295edf5@xxxxxxxxxxxxxxxxxxxxxxxxx > > tipc: TX() has been purged, node left! > ============================= > WARNING: suspicious RCU usage > 5.7.0-rc2-next-20200421-syzkaller #0 Not tainted > ----------------------------- > net/ipv4/ipmr.c:1757 RCU-list traversed in non-reader section!! > > other info that might help us debug this: > > > rcu_scheduler_active = 2, debug_locks = 1 > 4 locks held by kworker/u4:0/7: > #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: __write_once_size include/linux/compiler.h:250 [inline] > #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] > #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] > #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] > #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline] > #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] > #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 kernel/workqueue.c:2239 > #1: ffffc90000cdfdc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 kernel/workqueue.c:2243 > #2: ffffffff8a5a2b70 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 net/core/net_namespace.c:565 > #3: ffffffff8a5aeae8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0x88/0x700 net/ipv6/ip6_gre.c:1602 > > stack backtrace: > CPU: 0 PID: 7 Comm: kworker/u4:0 Not tainted 5.7.0-rc2-next-20200421-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Workqueue: netns cleanup_net > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x188/0x20d lib/dump_stack.c:118 > ipmr_device_event+0x240/0x2b0 net/ipv4/ipmr.c:1757 > notifier_call_chain+0xc0/0x230 kernel/notifier.c:83 > call_netdevice_notifiers_info net/core/dev.c:1948 [inline] > call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1933 > call_netdevice_notifiers_extack net/core/dev.c:1960 [inline] > call_netdevice_notifiers net/core/dev.c:1974 [inline] > rollback_registered_many+0x75c/0xe70 net/core/dev.c:8828 > unregister_netdevice_many.part.0+0x16/0x1e0 net/core/dev.c:9993 > unregister_netdevice_many+0x36/0x50 net/core/dev.c:9992 > ip6gre_exit_batch_net+0x4e8/0x700 net/ipv6/ip6_gre.c:1605 > ops_exit_list.isra.0+0x103/0x150 net/core/net_namespace.c:189 > cleanup_net+0x511/0xa50 net/core/net_namespace.c:603 > process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 > worker_thread+0x96/0xe20 kernel/workqueue.c:2414 > kthread+0x38b/0x470 kernel/kthread.c:274 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > > > --- > This bug 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 bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/0000000000004ede4505a3cab90e%40google.com.
