rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12/1:b..l rcu: (detected by 1, t=10502 jiffies, g=11233, q=127 ncpus=2) task:kworker/u4:1 state:R running task stack:24944 pid:12 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5301 [inline] __schedule+0x245a/0x5a60 kernel/sched/core.c:6619 preempt_schedule_notrace+0x5f/0xd0 kernel/sched/core.c:6881 preempt_schedule_notrace_thunk+0x1a/0x20 arch/x86/entry/thunk_64.S:35 rcu_read_unlock_sched_notrace include/linux/rcupdate.h:895 [inline] trace_lock_acquire+0x1e7/0x2b0 include/trace/events/lock.h:24 lock_acquire+0x32/0xc0 kernel/locking/lockdep.c:5662 rcu_lock_acquire include/linux/rcupdate.h:327 [inline] rcu_read_lock include/linux/rcupdate.h:773 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x131/0xfe0 net/batman-adv/network-coding.c:719 process_one_work+0x9bf/0x1820 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: rcu_preempt kthread starved for 10510 jiffies! g11233 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:28680 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5301 [inline] __schedule+0x245a/0x5a60 kernel/sched/core.c:6619 schedule+0xde/0x1a0 kernel/sched/core.c:6695 schedule_timeout+0x14e/0x2b0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1609 rcu_gp_kthread+0x23a/0x360 kernel/rcu/tree.c:1808 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 5741 Comm: syz-executor.2 Not tainted 6.2.0-rc6-next-20230203-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 RIP: 0010:lock_acquire.part.0+0x156/0x370 kernel/locking/lockdep.c:5656 Code: b8 ff ff ff ff 65 0f c1 05 07 84 9c 7e 83 f8 01 0f 85 c7 01 00 00 9c 58 f6 c4 02 0f 85 da 01 00 00 48 85 ed 0f 85 ad 01 00 00 <48> b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 00 00 00 48 c7 RSP: 0018:ffffc90005a8f238 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 1ffff92000b51e48 RCX: ffffffff8165aaa6 RDX: 1ffff11005511896 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000200 R08: 0000000000000000 R09: ffffffff913e4c1f R10: fffffbfff227c983 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88802a48a0d8 FS: 00007f2908784700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2907b15829 CR3: 0000000028780000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_write_lock include/linux/rwlock_api_smp.h:209 [inline] _raw_write_lock+0x2e/0x40 kernel/locking/spinlock.c:300 jbd2_log_start_commit+0x23/0x50 fs/jbd2/journal.c:521 jbd2_journal_stop+0x53b/0xfd0 fs/jbd2/transaction.c:1932 __ext4_journal_stop+0xe2/0x1f0 fs/ext4/ext4_jbd2.c:133 ext4_dirty_inode+0xf1/0x130 fs/ext4/inode.c:6111 __mark_inode_dirty+0x247/0x1250 fs/fs-writeback.c:2421 mark_inode_dirty include/linux/fs.h:2127 [inline] generic_write_end+0x354/0x440 fs/buffer.c:2227 ext4_da_write_end+0x1f5/0xa50 fs/ext4/inode.c:3174 generic_perform_write+0x316/0x570 mm/filemap.c:3781 ext4_buffered_write_iter+0x15b/0x460 fs/ext4/file.c:285 ext4_file_write_iter+0x8bf/0x1710 fs/ext4/file.c:700 call_write_iter include/linux/fs.h:1851 [inline] do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735 do_iter_write+0x182/0x700 fs/read_write.c:861 vfs_iter_write+0x74/0xa0 fs/read_write.c:902 iter_file_splice_write+0x745/0xc90 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x114/0x180 fs/splice.c:931 splice_direct_to_actor+0x335/0x8a0 fs/splice.c:886 do_splice_direct+0x1ab/0x280 fs/splice.c:974 do_sendfile+0xb19/0x12c0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1317 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x14d/0x210 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f2907a8c0c9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2908784168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f2907babf80 RCX: 00007f2907a8c0c9 RDX: 00000000200001c0 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 00007f2907ae7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000200a198 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffcafd348f R14: 00007f2908784300 R15: 0000000000022000