syzbot


WARNING: suspicious RCU usage in linkwatch_do_dev (2)

Status: upstream: reported on 2024/12/31 15:49
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+8ad3d259a2ccebee708d@syzkaller.appspotmail.com
First crash: 8d00h, last: 8d00h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [net?] WARNING: suspicious RCU usage in linkwatch_do_dev (2) 0 (1) 2024/12/31 15:49
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING: suspicious RCU usage in linkwatch_do_dev net 1 118d 118d 0/28 auto-obsoleted due to no activity on 2024/12/15 01:19

Sample crash report:
=============================
WARNING: suspicious RCU usage
6.13.0-rc4-syzkaller-00054-gd6ef8b40d075 #0 Not tainted
-----------------------------
net/sched/sch_generic.c:1290 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
 #0: ffff8881063bd948 ((wq_completion)bond0#10){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204

stack backtrace:
 lockdep_rcu_suspicious+0x210/0x3c0 kernel/locking/lockdep.c:6845
 dev_deactivate_queue+0x167/0x190 net/sched/sch_generic.c:1290
 netdev_for_each_tx_queue include/linux/netdevice.h:2562 [inline]
 dev_deactivate_many+0xe7/0xb20 net/sched/sch_generic.c:1363
 bond_check_dev_link+0x197/0x490 drivers/net/bonding/bond_main.c:873
 bond_miimon_inspect drivers/net/bonding/bond_main.c:2740 [inline]
 bond_mii_monitor+0x3c1/0x2d90 drivers/net/bonding/bond_main.c:2962
 </TASK>
WARNING: suspicious RCU usage
-----------------------------
other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
3 locks held by kworker/u32:8/1145:
stack backtrace:
CPU: 2 UID: 0 PID: 1145 Comm: kworker/u32:8 Not tainted 6.13.0-rc4-syzkaller-00054-gd6ef8b40d075 #0
Workqueue: bond0 bond_mii_monitor
 <TASK>
 linkwatch_do_dev+0x11e/0x160 net/core/link_watch.c:180
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120
 linkwatch_do_dev+0x11e/0x160 net/core/link_watch.c:180
 ethtool_op_get_link+0x1d/0x70 net/ethtool/ioctl.c:62
 bond_miimon_inspect drivers/net/bonding/bond_main.c:2740 [inline]
 bond_mii_monitor+0x3c1/0x2d90 drivers/net/bonding/bond_main.c:2962
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
=============================
-----------------------------
other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
 #0: ffff8881063bd948 ((wq_completion)bond0#10){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204

stack backtrace:
Call Trace:
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120
 bond_check_dev_link+0x197/0x490 drivers/net/bonding/bond_main.c:873
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
[ BUG: Invalid wait context ]
-----------------------------
other info that might help us debug this:
stack backtrace:
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 dev_deactivate_many+0x2a1/0xb20 net/sched/sch_generic.c:1377
 linkwatch_do_dev+0x11e/0x160 net/core/link_watch.c:180
 ethtool_op_get_link+0x1d/0x70 net/ethtool/ioctl.c:62
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 </TASK>
Tainted: [W]=WARN
Workqueue: bond0 bond_mii_monitor
RSP: 0018:ffffc90005f47390 EFLAGS: 00010082
RAX: 0000000000000000 RBX: ffff88806a83fb80 RCX: ffffffff815a50d9
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R13: ffff888026f7a440 R14: ffff888026f7a440 R15: ffff88806a83ebc0
CR2: 00007ffe20f4de14 CR3: 00000000317f2000 CR4: 0000000000352ef0
Call Trace:
 __schedule+0x297/0x5ad0 kernel/sched/core.c:6661
 mutex_optimistic_spin kernel/locking/mutex.c:485 [inline]
 __mutex_lock_common kernel/locking/mutex.c:589 [inline]
 __mutex_lock+0x8a1/0xa60 kernel/locking/mutex.c:735
 exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329
 synchronize_rcu_expedited+0x290/0x450 kernel/rcu/tree_exp.h:976
 dev_deactivate_many+0x2a1/0xb20 net/sched/sch_generic.c:1377
 linkwatch_sync_dev+0x181/0x210 net/core/link_watch.c:268
 bond_check_dev_link+0x197/0x490 drivers/net/bonding/bond_main.c:873
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/12/27 15:39 upstream d6ef8b40d075 d3ccff63 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: suspicious RCU usage in linkwatch_do_dev
* Struck through repros no longer work on HEAD.