syzbot

INFO: task syz.0.9:5976 blocked for more than 143 seconds.
      Not tainted 6.14.0-syzkaller-12508-g92b71befc349 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.9         state:D stack:27944 pid:5976  tgid:5943  ppid:5830   task_flags:0x400040 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x163/0x360 kernel/sched/core.c:6860
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
 rwsem_down_write_slowpath+0xedd/0x1420 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write+0x1da/0x220 kernel/locking/rwsem.c:1578
 inode_lock include/linux/fs.h:867 [inline]
 chown_common+0x3e3/0x850 fs/open.c:772
 vfs_fchown fs/open.c:850 [inline]
 ksys_fchown+0xe2/0x150 fs/open.c:862
 __do_sys_fchown fs/open.c:867 [inline]
 __se_sys_fchown fs/open.c:865 [inline]
 __x64_sys_fchown+0x7a/0x90 fs/open.c:865
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f298a38d169
RSP: 002b:00007f298b135038 EFLAGS: 00000246 ORIG_RAX: 000000000000005d
RAX: ffffffffffffffda RBX: 00007f298a5a6080 RCX: 00007f298a38d169
RDX: 000000000000000a RSI: 000000003a736e6f RDI: 0000000000000006
RBP: 00007f298a40e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f298a5a6080 R15: 00007fff2db8a248
 </TASK>
INFO: task syz.0.9:5977 blocked for more than 143 seconds.
      Not tainted 6.14.0-syzkaller-12508-g92b71befc349 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.9         state:D stack:27944 pid:5977  tgid:5943  ppid:5830   task_flags:0x400040 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x163/0x360 kernel/sched/core.c:6860
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
 rwsem_down_write_slowpath+0xedd/0x1420 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write+0x1da/0x220 kernel/locking/rwsem.c:1578
 inode_lock include/linux/fs.h:867 [inline]
 chown_common+0x3e3/0x850 fs/open.c:772
 vfs_fchown fs/open.c:850 [inline]
 ksys_fchown+0xe2/0x150 fs/open.c:862
 __do_sys_fchown fs/open.c:867 [inline]
 __se_sys_fchown fs/open.c:865 [inline]
 __x64_sys_fchown+0x7a/0x90 fs/open.c:865
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f298a38d169
RSP: 002b:00007f298b114038 EFLAGS: 00000246 ORIG_RAX: 000000000000005d
RAX: ffffffffffffffda RBX: 00007f298a5a6160 RCX: 00007f298a38d169
RDX: 000000000000000a RSI: 000000003a736e6f RDI: 0000000000000008
RBP: 00007f298a40e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f298a5a6160 R15: 00007fff2db8a248
 </TASK>
INFO: task syz.0.9:5978 blocked for more than 144 seconds.
      Not tainted 6.14.0-syzkaller-12508-g92b71befc349 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.9         state:D stack:27944 pid:5978  tgid:5943  ppid:5830   task_flags:0x400040 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x163/0x360 kernel/sched/core.c:6860
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
 rwsem_down_read_slowpath kernel/locking/rwsem.c:1084 [inline]
 __down_read_common kernel/locking/rwsem.c:1248 [inline]
 __down_read kernel/locking/rwsem.c:1261 [inline]
 down_read+0x6ff/0xa50 kernel/locking/rwsem.c:1526
 inode_lock_shared include/linux/fs.h:877 [inline]
 lookup_slow+0x45/0x70 fs/namei.c:1823
 walk_component+0x2f4/0x420 fs/namei.c:2128
 lookup_last fs/namei.c:2626 [inline]
 path_lookupat+0x169/0x440 fs/namei.c:2650
 filename_lookup+0x290/0x670 fs/namei.c:2679
 vfs_statx fs/stat.c:346 [inline]
 vfs_fstatat fs/stat.c:368 [inline]
 vfs_lstat+0xb1/0x440 include/linux/fs.h:3507
 __do_sys_newlstat fs/stat.c:518 [inline]
 __se_sys_newlstat fs/stat.c:512 [inline]
 __x64_sys_newlstat+0xd9/0x160 fs/stat.c:512
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f298a38d169
RSP: 002b:00007f2987df4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000006
RAX: ffffffffffffffda RBX: 00007f298a5a6240 RCX: 00007f298a38d169
RDX: 0000000000000000 RSI: 0000200000000200 RDI: 00002000000024c0
RBP: 00007f298a40e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f298a5a6240 R15: 00007fff2db8a248
 </TASK>
INFO: task syz.0.9:5979 blocked for more than 144 seconds.
      Not tainted 6.14.0-syzkaller-12508-g92b71befc349 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.9         state:D stack:27944 pid:5979  tgid:5943  ppid:5830   task_flags:0x400040 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x163/0x360 kernel/sched/core.c:6860
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
 rwsem_down_read_slowpath kernel/locking/rwsem.c:1084 [inline]
 __down_read_common kernel/locking/rwsem.c:1248 [inline]
 __down_read kernel/locking/rwsem.c:1261 [inline]
 down_read+0x6ff/0xa50 kernel/locking/rwsem.c:1526
 inode_lock_shared include/linux/fs.h:877 [inline]
 lookup_slow+0x45/0x70 fs/namei.c:1823
 walk_component fs/namei.c:2128 [inline]
 link_path_walk+0x969/0xeb0 fs/namei.c:2493
 path_parentat+0x28/0xa0 fs/namei.c:2697
 __filename_parentat+0x60f/0x780 fs/namei.c:2723
 filename_parentat fs/namei.c:2739 [inline]
 filename_create+0xfb/0x490 fs/namei.c:4078
 do_mkdirat+0xbf/0x3f0 fs/namei.c:4349
 __do_sys_mkdirat fs/namei.c:4374 [inline]
 __se_sys_mkdirat fs/namei.c:4372 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4372
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f298a38b9d7
RSP: 002b:00007f29879d0e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f29879d0ef0 RCX: 00007f298a38b9d7
RDX: 00000000000001ff RSI: 00002000000000c0 RDI: 00000000ffffff9c
RBP: 0000200000000000 R08: 0000200000000480 R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 00002000000000c0
R13: 00007f29879d0eb0 R14: 0000000000000000 R15: 0000200000000280
 </TASK>

Showing all locks held in the system:
1 lock held by kworker/u8:0/12:
1 lock held by khungtaskd/31:
 #0: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764
2 locks held by kworker/u8:4/76:
4 locks held by kworker/u8:5/1054:
4 locks held by kworker/u8:10/3026:
 #0: ffff88801bef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801bef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319
 #1: ffffc9000ba97c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc9000ba97c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319
 #2: ffffffff900dd3d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17c/0xd60 net/core/net_namespace.c:608
 #3: ffffffff8ed433c0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3774
2 locks held by getty/5582:
 #0: ffff8880349a00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x53d/0x16b0 drivers/tty/n_tty.c:2211
5 locks held by syz.0.9/5944:
 #0: ffff888030888420 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:556
 #1: ffff88805af20148 (&sb->s_type->i_mutex_key#22/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline]
 #1: ffff88805af20148 (&sb->s_type->i_mutex_key#22/1){+.+.}-{4:4}, at: filename_create+0x266/0x490 fs/namei.c:4097
 #2: ffff88805af20530 (&inode->ei_update_lock){+.+.}-{4:4}, at: __bch2_create+0x359/0xf40 fs/bcachefs/fs.c:550
 #3: ffff888056a04210 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
 #3: ffff888056a04210 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
 #3: ffff888056a04210 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7ed/0xd40 fs/bcachefs/btree_iter.c:3386
 #4: ffff888056a26550 (&c->gc_lock){.+.+}-{4:4}, at: bch2_btree_update_start+0x68a/0x16c0 fs/bcachefs/btree_update_interior.c:1179
2 locks held by syz.0.9/5976:
 #0: ffff888030888420 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write_file+0x5e/0x200 fs/namespace.c:600
 #1: ffff88805af20148 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
 #1: ffff88805af20148 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: chown_common+0x3e3/0x850 fs/open.c:772
2 locks held by syz.0.9/5977:
 #0: ffff888030888420 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write_file+0x5e/0x200 fs/namespace.c:600
 #1: ffff88805af20148 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
 #1: ffff88805af20148 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: chown_common+0x3e3/0x850 fs/open.c:772
1 lock held by syz.0.9/5978:
 #0: ffff88805af20148 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:877 [inline]
 #0: ffff88805af20148 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: lookup_slow+0x45/0x70 fs/namei.c:1823
1 lock held by syz.0.9/5979:
 #0: ffff88805af20148 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:877 [inline]
 #0: ffff88805af20148 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: lookup_slow+0x45/0x70 fs/namei.c:1823
2 locks held by bch-copygc/loop/5974:
2 locks held by syz-executor/6458:
2 locks held by syz-executor/6712:
3 locks held by syz.6.260/7875:
1 lock held by syz.6.260/7886:
 #0: ffff88803425f8e8 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: process_measurement+0x7d6/0x1fe0 security/integrity/ima/ima_main.c:277
2 locks held by syz.6.260/7889:
2 locks held by syz.8.257/7884:
1 lock held by syz.9.263/7893:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-syzkaller-12508-g92b71befc349 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
 watchdog+0x1058/0x10a0 kernel/hung_task.c:437
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 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: 12 Comm: kworker/u8:0 Not tainted 6.14.0-syzkaller-12508-g92b71befc349 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:check_preemption_disabled+0x63/0x120 lib/smp_processor_id.c:19
Code: 3b 44 24 08 0f 85 cc 00 00 00 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 <f7> 04 24 00 02 00 00 74 c7 49 89 f6 49 89 ff 65 4c 8b 2c 25 08 10
RSP: 0018:ffffc900001179f8 EFLAGS: 00000046
RAX: 0000000080000000 RBX: 0000000000000001 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8e750f72 RDI: ffffffff8ca0d700
RBP: ffffffff93651020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff93651020
R13: 0000000000000002 R14: 0000000000000246 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881250cf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3dc1fea000 CR3: 000000000eb38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lockdep_recursion_inc kernel/locking/lockdep.c:467 [inline]
 lock_acquire+0xdb/0x2f0 kernel/locking/lockdep.c:5865
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xec/0x610 net/batman-adv/network-coding.c:719
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd50 kernel/workqueue.c:3400
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>