syzbot

INFO: task syz.8.1045:13629 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.1045      state:D stack:26688 pid:13629 tgid:13628 ppid:11939  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0x1553/0x5240 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289
 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
 __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
 __rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114
 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
 __down_read kernel/locking/rwsem.c:1466 [inline]
 down_read+0x132/0x200 kernel/locking/rwsem.c:1539
 __super_lock fs/super.c:60 [inline]
 super_lock+0x2d6/0x3d0 fs/super.c:122
 user_get_super+0xc8/0x120 fs/super.c:1001
 quotactl_block fs/quota/quota.c:889 [inline]
 __do_sys_quotactl fs/quota/quota.c:955 [inline]
 __se_sys_quotactl+0x540/0x9e0 fs/quota/quota.c:917
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9aada4c799
RSP: 002b:00007f9aabca6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f9aadcc5fa0 RCX: 00007f9aada4c799
RDX: 0000000000000000 RSI: 0000200000000040 RDI: ffffffff80000800
RBP: 00007f9aadae2c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000100 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9aadcc6038 R14: 00007f9aadcc5fa0 R15: 00007fffc894ac08
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/38:
 #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:3/44:
 #0: ffff88801d361138 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #0: ffff88801d361138 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
 #1: ffffc90000b67c40 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
 #1: ffffc90000b67c40 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
 #2: ffffffff8f15ac38 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_dfs_channels_update_work+0xd6/0x660 net/wireless/mlme.c:1040
3 locks held by kworker/u8:6/169:
 #0: ffff888032153138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #0: ffff888032153138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
 #1: ffffc90003bcfc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
 #1: ffffc90003bcfc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
 #2: ffffffff8f15ac38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8f15ac38 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4198
5 locks held by kworker/u8:8/1061:
 #0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
 #1: ffffc90005aa7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
 #1: ffffc90005aa7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
 #2: ffffffff8f14c480 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675
 #3: ffffffff8f15ac38 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1683
 #4: ffff8880368308b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6441 [inline]
 #4: ffff8880368308b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_stop+0x126/0x240 net/mac80211/iface.c:822
2 locks held by getty/5551:
 #0: ffff8880372960a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
7 locks held by udevd/5812:
1 lock held by udevd/5813:
2 locks held by syz-executor/6441:
1 lock held by syz.8.1045/13629:
 #0: ffff888067cda0d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
 #0: ffff888067cda0d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz.2.1192/14698:
 #0: ffff888067cda0d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
 #0: ffff888067cda0d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz-executor/15230:
 #0: ffffffff8f15ac38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8f15ac38 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5031
2 locks held by syz-executor/15546:
 #0: ffffffff8f6bde98 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8f6bde98 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8f6bde98 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f15ac38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f15ac38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f15ac38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071
4 locks held by syz.1.1329/15714:
2 locks held by syz.5.1330/15720:
 #0: ffff88806a21a0d0 (&type->s_umount_key#57/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345
 #1: ffffffff8dc6bab8 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5279 [inline]
 #1: ffffffff8dc6bab8 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0x9ef/0x1e90 kernel/workqueue.c:5832
4 locks held by dhcpcd-run-hook/15737:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xfd9/0x1030 kernel/hung_task.c:515
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5813 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:246 [inline]
RIP: 0010:__sanitizer_cov_trace_switch+0xb2/0x140 kernel/kcov.c:351
Code: eb 0c 49 ff c1 4c 39 c8 0f 84 86 00 00 00 4e 8b 5c ce 10 65 8b 2d 5e c2 89 10 81 e5 00 00 ff 00 41 8b 98 a4 0b 00 00 44 21 d3 <41> 89 de 41 09 ee 74 12 85 ed 75 cc 85 db 74 c8 41 83 b8 74 16 00
RSP: 0018:ffffc900045ff550 EFLAGS: 00000246
RAX: 0000000000000004 RBX: 0000000000000000 RCX: 0000000000000005
RDX: ffffffff8b1b1974 RSI: ffffffff8f5137b0 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffff888036b45b80 R09: 0000000000000001
R10: 0000000000000100 R11: 0000000000000001 R12: dffffc0000000000
R13: ffff88801184f600 R14: 0000000000000000 R15: ffffc900045ff7e0
FS:  00007f5bda793880(0000) GS:ffff88812643c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5bd9e2c000 CR3: 0000000059da8000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ma_slots lib/maple_tree.c:708 [inline]
 mas_prev_slot+0x384/0xbb0 lib/maple_tree.c:4224
 vma_prev include/linux/mm.h:1335 [inline]
 vma_iter_next_rewind mm/vma.h:642 [inline]
 __mmap_setup mm/vma.c:2421 [inline]
 __mmap_region mm/vma.c:2741 [inline]
 mmap_region+0x798/0x2230 mm/vma.c:2837
 do_mmap+0xc2f/0x10c0 mm/mmap.c:559
 vm_mmap_pgoff+0x2cc/0x4f0 mm/util.c:581
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5bda8f7822
Code: 00 00 00 0f 1f 44 00 00 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 3b 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 76 5b 5d c3 0f 1f 00 48 8b 05 a1 35 0d 00 64
RSP: 002b:00007ffcc3d71658 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5bda8f7822
RDX: 0000000000000003 RSI: 0000000000000200 RDI: 0000000000000000
RBP: 0000000000000022 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000000018
R13: 0000000000000600 R14: 00005591398266b0 R15: 0000000000000400
 </TASK>