rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6460/1:b..l rcu: (detected by 1, t=10502 jiffies, g=39821, q=518 ncpus=2) task:syz-executor.2 state:R running task stack:20280 pid:6460 tgid:6459 ppid:5503 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x1796/0x4a00 kernel/sched/core.c:6745 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7067 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_is_held_type+0x13b/0x190 Code: 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 42 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc900053c7198 EFLAGS: 00000206 RAX: c4017c3b79cd4700 RBX: 0000000000000001 RCX: 0000000080000000 RDX: ffff888029d3da00 RSI: ffffffff8bcaca00 RDI: ffffffff8c1f0da0 RBP: 0000000000000002 R08: ffffffff8b7af827 R09: 1ffffffff25ef4b0 R10: dffffc0000000000 R11: fffffbfff25ef4b1 R12: 0000000000000246 R13: ffff888029d3da00 R14: 00000000ffffffff R15: ffffffff8e333d20 xa_entry include/linux/xarray.h:1220 [inline] xas_descend lib/xarray.c:207 [inline] xas_load+0x478/0x5c0 lib/xarray.c:245 filemap_get_entry+0x1fe/0x4e0 mm/filemap.c:1840 __filemap_get_folio+0x65/0xbb0 mm/filemap.c:1885 __find_get_block_slow fs/buffer.c:203 [inline] __find_get_block+0x257/0x10d0 fs/buffer.c:1410 __getblk_slow fs/buffer.c:1137 [inline] bdev_getblk+0x1c5/0x610 fs/buffer.c:1443 __bread_gfp+0xac/0x430 fs/buffer.c:1497 sb_bread include/linux/buffer_head.h:347 [inline] get_branch+0x2c3/0x6e0 fs/sysv/itree.c:102 get_block+0x170/0x1790 fs/sysv/itree.c:222 block_read_full_folio+0x42e/0xe10 fs/buffer.c:2407 filemap_read_folio+0x1a0/0x790 mm/filemap.c:2355 do_read_cache_folio+0x134/0x820 mm/filemap.c:3788 do_read_cache_page+0x30/0x200 mm/filemap.c:3854 read_mapping_page include/linux/pagemap.h:888 [inline] dir_get_page fs/sysv/dir.c:64 [inline] sysv_find_entry+0x1af/0x410 fs/sysv/dir.c:157 sysv_inode_by_name+0x98/0x1f0 fs/sysv/dir.c:374 sysv_lookup+0x6b/0xe0 fs/sysv/namei.c:38 lookup_one_qstr_excl+0x11f/0x260 fs/namei.c:1607 filename_create+0x297/0x540 fs/namei.c:3901 do_mkdirat+0xbd/0x3a0 fs/namei.c:4146 __do_sys_mkdirat fs/namei.c:4169 [inline] __se_sys_mkdirat fs/namei.c:4167 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4167 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd37527cee9 RSP: 002b:00007fd3760c50c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fd3753abf80 RCX: 00007fd37527cee9 RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000004 RBP: 00007fd3752c949e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fd3753abf80 R15: 00007ffd67531698 rcu: rcu_preempt kthread starved for 10548 jiffies! g39821 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:25360 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x1796/0x4a00 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:2000 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2202 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 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8822 Comm: syz-executor.0 Not tainted 6.9.0-syzkaller-10215-g72ece20127a3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:entry_SYSCALL_64+0xf/0x2b arch/x86/entry/entry_64.S:94 Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 01 f8 65 48 89 25 85 9f 60 74 <66> 90 0f 20 dc 0f 1f 44 00 00 48 81 e4 ff e7 ff ff 0f 22 dc 65 48 RSP: 0018:00007fb9a4907178 EFLAGS: 00000002 RAX: 00000000000000ca RBX: 00007fb9a3dac128 RCX: 00007fb9a3c7cee9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb9a3dac128 RBP: 00007fb9a3dac120 R08: 00007fb9a49076c0 R09: 00007fb9a49076c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb9a3dac12c R13: 000000000000006e R14: 00007fffa3a7fd80 R15: 00007fffa3a7fe68 FS: 00007fb9a49076c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb9a4906f80 CR3: 000000005b35a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: sched: RT throttling activated