Subject: Re: [syzbot] [net?] WARNING: suspicious RCU usage in dev_activate

From: syzbot <[email-masked]>
Date: Sun, 15 Sep 2024 20:23:24 -0700

syzbot has found a reproducer for the following issue on:

HEAD commit:    d42f7708e27c Merge tag 'for-linus-6.11' of git://git.kerne..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1187229f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=61d235cb8d15001c
dashboard link: https://syzkaller.appspot.com/bug?extid=2120b9a8f96b3fa90bad
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15c828a9980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1587229f980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/92f659e09436/disk-d42f7708.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1e3b5ab99922/vmlinux-d42f7708.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1c82035e4680/bzImage-d42f7708.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

=============================
WARNING: suspicious RCU usage
6.11.0-rc7-syzkaller-00151-gd42f7708e27c #0 Not tainted
-----------------------------
net/sched/sch_generic.c:1250 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
3 locks held by kworker/u8:14/3029:
 #0: ffff88807741a948 ((wq_completion)bond0#3){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff88807741a948 ((wq_completion)bond0#3){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc9000a2c7d00 ((work_completion)(&(&bond->mii_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc9000a2c7d00 ((work_completion)(&(&bond->mii_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: bond_mii_monitor+0x174/0x3170 drivers/net/bonding/bond_main.c:2863

stack backtrace:
CPU: 1 UID: 0 PID: 3029 Comm: kworker/u8:14 Not tainted 6.11.0-rc7-syzkaller-00151-gd42f7708e27c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: bond0 bond_mii_monitor
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6724
 dev_activate+0xf8/0x1240 net/sched/sch_generic.c:1250
 linkwatch_do_dev+0xfb/0x170 net/core/link_watch.c:173
 ethtool_op_get_link+0x15/0x60 net/ethtool/ioctl.c:62
 bond_check_dev_link+0x1f1/0x3f0 drivers/net/bonding/bond_main.c:799
 bond_miimon_inspect drivers/net/bonding/bond_main.c:2643 [inline]
 bond_mii_monitor+0x49a/0x3170 drivers/net/bonding/bond_main.c:2865
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
 worker_thread+0x870/0xd30 kernel/workqueue.c:3393
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

=============================
WARNING: suspicious RCU usage
6.11.0-rc7-syzkaller-00151-gd42f7708e27c #0 Not tainted
-----------------------------
net/sched/sch_generic.c:1228 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
3 locks held by kworker/u8:14/3029:
 #0: ffff88807741a948 ((wq_completion)bond0#3){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff88807741a948 ((wq_completion)bond0#3){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc9000a2c7d00 ((work_completion)(&(&bond->mii_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc9000a2c7d00 ((work_completion)(&(&bond->mii_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: bond_mii_monitor+0x174/0x3170 drivers/net/bonding/bond_main.c:2863

stack backtrace:
CPU: 0 UID: 0 PID: 3029 Comm: kworker/u8:14 Not tainted 6.11.0-rc7-syzkaller-00151-gd42f7708e27c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: bond0 bond_mii_monitor
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6724
 transition_one_qdisc+0x8e/0x1c0 net/sched/sch_generic.c:1228
 netdev_for_each_tx_queue include/linux/netdevice.h:2513 [inline]
 dev_activate+0x838/0x1240 net/sched/sch_generic.c:1258
 linkwatch_do_dev+0xfb/0x170 net/core/link_watch.c:173
 ethtool_op_get_link+0x15/0x60 net/ethtool/ioctl.c:62
 bond_check_dev_link+0x1f1/0x3f0 drivers/net/bonding/bond_main.c:799
 bond_miimon_inspect drivers/net/bonding/bond_main.c:2643 [inline]
 bond_mii_monitor+0x49a/0x3170 drivers/net/bonding/bond_main.c:2865
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
 worker_thread+0x870/0xd30 kernel/workqueue.c:3393
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

=============================
WARNING: suspicious RCU usage
6.11.0-rc7-syzkaller-00151-gd42f7708e27c #0 Not tainted
-----------------------------
include/linux/rtnetlink.h:100 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
3 locks held by kworker/u8:14/3029:
 #0: ffff88807741a948 ((wq_completion)bond0#3){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff88807741a948 ((wq_completion)bond0#3){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc9000a2c7d00 ((work_completion)(&(&bond->mii_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc9000a2c7d00 ((work_completion)(&(&bond->mii_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: bond_mii_monitor+0x174/0x3170 drivers/net/bonding/bond_main.c:2863

stack backtrace:
CPU: 1 UID: 0 PID: 3029 Comm: kworker/u8:14 Not tainted 6.11.0-rc7-syzkaller-00151-gd42f7708e27c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: bond0 bond_mii_monitor
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6724
 dev_ingress_queue include/linux/rtnetlink.h:100 [inline]
 dev_activate+0x925/0x1240 net/sched/sch_generic.c:1259
 linkwatch_do_dev+0xfb/0x170 net/core/link_watch.c:173
 ethtool_op_get_link+0x15/0x60 net/ethtool/ioctl.c:62
 bond_check_dev_link+0x1f1/0x3f0 drivers/net/bonding/bond_main.c:799
 bond_miimon_inspect drivers/net/bonding/bond_main.c:2643 [inline]
 bond_mii_monitor+0x49a/0x3170 drivers/net/bonding/bond_main.c:2865
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
 worker_thread+0x870/0xd30 kernel/workqueue.c:3393
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1525
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 3029, name: kworker/u8:14
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
3 locks held by kworker/u8:14/3029:
 #0: ffff88807741a948 ((wq_completion)bond0#3){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff88807741a948 ((wq_completion)bond0#3){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc9000a2c7d00 ((work_completion)(&(&bond->mii_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc9000a2c7d00 ((work_completion)(&(&bond->mii_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: bond_mii_monitor+0x174/0x3170 drivers/net/bonding/bond_main.c:2863
CPU: 0 UID: 0 PID: 3029 Comm: kworker/u8:14 Not tainted 6.11.0-rc7-syzkaller-00151-gd42f7708e27c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: bond0 bond_mii_monitor
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 __might_resched+0x5d4/0x780 kernel/sched/core.c:8463
 down_read+0x8e/0xa40 kernel/locking/rwsem.c:1525
 wireless_nlevent_flush net/wireless/wext-core.c:351 [inline]
 wext_netdev_notifier_call+0x1f/0x120 net/wireless/wext-core.c:371
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 netdev_state_change+0x11f/0x1a0 net/core/dev.c:1376
 linkwatch_do_dev+0x112/0x170 net/core/link_watch.c:177
 ethtool_op_get_link+0x15/0x60 net/ethtool/ioctl.c:62
 bond_check_dev_link+0x1f1/0x3f0 drivers/net/bonding/bond_main.c:799
 bond_miimon_inspect drivers/net/bonding/bond_main.c:2643 [inline]
 bond_mii_monitor+0x49a/0x3170 drivers/net/bonding/bond_main.c:2865
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
 worker_thread+0x870/0xd30 kernel/workqueue.c:3393
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

=============================
[ BUG: Invalid wait context ]
6.11.0-rc7-syzkaller-00151-gd42f7708e27c #0 Tainted: G        W         
-----------------------------
kworker/u8:14/3029 is trying to lock:
ffffffff8fc7f690 (net_rwsem){++++}-{3:3}, at: wireless_nlevent_flush net/wireless/wext-core.c:351 [inline]
ffffffff8fc7f690 (net_rwsem){++++}-{3:3}, at: wext_netdev_notifier_call+0x1f/0x120 net/wireless/wext-core.c:371
other info that might help us debug this:
context-{4:4}
3 locks held by kworker/u8:14/3029:
 #0: ffff88807741a948 ((wq_completion)bond0#3){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff88807741a948 ((wq_completion)bond0#3){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc9000a2c7d00 ((work_completion)(&(&bond->mii_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc9000a2c7d00 ((work_completion)(&(&bond->mii_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: bond_mii_monitor+0x174/0x3170 drivers/net/bonding/bond_main.c:2863
stack backtrace:
CPU: 0 UID: 0 PID: 3029 Comm: kworker/u8:14 Tainted: G        W          6.11.0-rc7-syzkaller-00151-gd42f7708e27c #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: bond0 bond_mii_monitor
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 print_lock_invalid_wait_context kernel/locking/lockdep.c:4750 [inline]
 check_wait_context kernel/locking/lockdep.c:4820 [inline]
 __lock_acquire+0x153b/0x2040 kernel/locking/lockdep.c:5092
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526
 wireless_nlevent_flush net/wireless/wext-core.c:351 [inline]
 wext_netdev_notifier_call+0x1f/0x120 net/wireless/wext-core.c:371
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 netdev_state_change+0x11f/0x1a0 net/core/dev.c:1376
 linkwatch_do_dev+0x112/0x170 net/core/link_watch.c:177
 ethtool_op_get_link+0x15/0x60 net/ethtool/ioctl.c:62
 bond_check_dev_link+0x1f1/0x3f0 drivers/net/bonding/bond_main.c:799
 bond_miimon_inspect drivers/net/bonding/bond_main.c:2643 [inline]
 bond_mii_monitor+0x49a/0x3170 drivers/net/bonding/bond_main.c:2865
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
 worker_thread+0x870/0xd30 kernel/workqueue.c:3393
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
bond0: (slave bridge0): link status definitely down, disabling slave
wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50

---
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#syz test: git://repo/address.git branch-or-commit-hash
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