rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=a8ec/1/0x4000000000000000 softirq=13887/13888 fqs=1802 (t=10000 jiffies g=2613 q=257838 ncpus=2) rcu: rcu_preempt kthread starved for 6313 jiffies! g2613 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:14016 pid:14 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x568/0x840 kernel/sched/core.c:6561 schedule+0x50/0xb0 kernel/sched/core.c:6637 schedule_timeout+0x111/0x180 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x185/0x510 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x18/0x100 kernel/rcu/tree.c:1905 kthread+0xcc/0xe0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4487 Comm: syz.8.21 Not tainted 6.1.146-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__memmove+0x3/0x1a0 arch/x86/lib/memmove_64.S:32 Code: 74 14 80 7b 2c 00 74 0e 80 7b 34 00 74 08 31 c0 80 7b 3c 00 75 d5 b8 ea ff ff ff 5b c3 00 00 00 00 cc cc 00 00 cc cc 48 89 f8 <48> 39 fe 7d 0f 49 89 f0 49 01 d0 49 39 f8 0f 8f a9 00 00 00 48 83 RSP: 0018:ffffc90001ea3410 EFLAGS: 00000202 RAX: ffffc90001ea3590 RBX: ffffc90001ea358f RCX: 000000007ffffffd RDX: 0000000000000005 RSI: ffffc90001ea358f RDI: ffffc90001ea3590 RBP: ffffffff82ab5fe7 R08: 0000000000000006 R09: 0000000000000005 R10: 0000000000000000 R11: 0000001000000000 R12: ffffc90001ea358f R13: 0000000000000003 R14: 0000000000000001 R15: ffffc90081ea358d FS: 00007ff37e0716c0(0000) GS:ffff888237d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30e5ffff CR3: 00000001642c5000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: move_right+0x38/0x50 lib/vsprintf.c:601 widen_string+0x3b/0xc0 lib/vsprintf.c:624 vsnprintf+0x386/0x550 lib/vsprintf.c:2805 sprintf+0x63/0x80 lib/vsprintf.c:3009 print_caller kernel/printk/printk.c:1285 [inline] info_print_prefix+0xf5/0x130 kernel/printk/printk.c:1302 record_print_text+0x82/0x1a0 kernel/printk/printk.c:1349 console_emit_next_record+0x35a/0x550 kernel/printk/printk.c:2760 console_flush_all kernel/printk/printk.c:-1 [inline] console_unlock+0x14e/0x280 kernel/printk/printk.c:2906 vprintk_emit+0xe0/0x3a0 kernel/printk/printk.c:2303 _printk+0x54/0x70 kernel/printk/printk.c:2328 _erofs_err+0x76/0x90 fs/erofs/super.c:35 z_erofs_pcluster_readmore+0x164/0x2d0 fs/erofs/zdata.c:1668 z_erofs_read_folio+0xa4/0x1c0 fs/erofs/zdata.c:1691 filemap_read_folio+0x40/0x1d0 mm/filemap.c:2490 do_read_cache_folio+0xf5/0x2a0 mm/filemap.c:3627 erofs_bread+0x72/0x1b0 fs/erofs/data.c:50 erofs_find_target_block fs/erofs/namei.c:102 [inline] erofs_namei+0xfa/0x440 fs/erofs/namei.c:175 erofs_lookup+0x7f/0x120 fs/erofs/namei.c:204 __lookup_slow+0x132/0x1b0 fs/namei.c:1690 lookup_slow+0x2e/0x50 fs/namei.c:1707 walk_component+0xce/0xe0 fs/namei.c:1998 lookup_last fs/namei.c:2455 [inline] path_lookupat+0x46/0xf0 fs/namei.c:2479 filename_lookup+0xd2/0x1e0 fs/namei.c:2508 vfs_statx+0x80/0x210 fs/stat.c:229 vfs_fstatat fs/stat.c:267 [inline] __do_sys_newfstatat fs/stat.c:437 [inline] __se_sys_newfstatat+0x83/0x2c0 fs/stat.c:431 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ff37d18e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff37e071038 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007ff37d3b5fa0 RCX: 00007ff37d18e929 RDX: 0000000000000000 RSI: 0000200000000200 RDI: ffffffffffffff9c RBP: 00007ff37d210b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000006000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff37d3b5fa0 R15: 00007ffe85637628 CPU: 0 PID: 2396 Comm: syz.4.20 Not tainted 6.1.146-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:console_emit_next_record+0x4f2/0x550 kernel/printk/printk.c:2786 Code: b0 00 00 00 f7 84 24 b0 00 00 00 00 02 00 00 75 32 f7 44 24 08 00 02 00 00 0f b6 44 24 07 74 01 fb 65 48 8b 0c 25 28 00 00 00 <48> 3b 8c 24 d0 00 00 00 75 43 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 RSP: 0018:ffffc90001df3600 EFLAGS: 00000206 RAX: 0000000000000001 RBX: ffffffff810e69d6 RCX: 4a9cbb8cc3573c00 RDX: 0000000000000001 RSI: ffffffff82bfed0a RDI: ffffffff82b56c7b RBP: ffffc90001df3710 R08: 0000000000000000 R09: 0000000000000003 R10: 6c20656369766564 R11: 28203a73666f7265 R12: ffffffff878be970 R13: ffffc90001df3727 R14: 0000000000000001 R15: ffffffff878c09b0 FS: 00007fb95e64b6c0(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2bc5ffff CR3: 0000000108b2f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: console_flush_all kernel/printk/printk.c:-1 [inline] console_unlock+0x14e/0x280 kernel/printk/printk.c:2906 vprintk_emit+0xe0/0x3a0 kernel/printk/printk.c:2303 _printk+0x54/0x70 kernel/printk/printk.c:2328 _erofs_err+0x76/0x90 fs/erofs/super.c:35 z_erofs_pcluster_readmore+0x164/0x2d0 fs/erofs/zdata.c:1668 z_erofs_read_folio+0xa4/0x1c0 fs/erofs/zdata.c:1691 filemap_read_folio+0x40/0x1d0 mm/filemap.c:2490 do_read_cache_folio+0xf5/0x2a0 mm/filemap.c:3627 erofs_bread+0x72/0x1b0 fs/erofs/data.c:50 erofs_find_target_block fs/erofs/namei.c:102 [inline] erofs_namei+0xfa/0x440 fs/erofs/namei.c:175 erofs_lookup+0x7f/0x120 fs/erofs/namei.c:204 __lookup_slow+0x132/0x1b0 fs/namei.c:1690 lookup_slow+0x2e/0x50 fs/namei.c:1707 walk_component+0xce/0xe0 fs/namei.c:1998 lookup_last fs/namei.c:2455 [inline] path_lookupat+0x46/0xf0 fs/namei.c:2479 filename_lookup+0xd2/0x1e0 fs/namei.c:2508 vfs_statx+0x80/0x210 fs/stat.c:229 vfs_fstatat fs/stat.c:267 [inline] __do_sys_newfstatat fs/stat.c:437 [inline] __se_sys_newfstatat+0x83/0x2c0 fs/stat.c:431 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb95d78e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb95e64b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007fb95d9b5fa0 RCX: 00007fb95d78e929 RDX: 0000000000000000 RSI: 0000200000000200 RDI: ffffffffffffff9c RBP: 00007fb95d810b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000006000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb95d9b5fa0 R15: 00007fffb80c8b28