rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (9843 ticks this GP) idle=ecdc/1/0x4000000000000000 softirq=26639/26639 fqs=777
rcu: 	(t=10501 jiffies g=19369 q=1084 ncpus=2)
rcu: rcu_preempt kthread starved for 8930 jiffies! g19369 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:26536 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x16f5/0x4d00
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 7602 Comm: syz-executor Not tainted 6.16.0-rc6-syzkaller-00411-g95993dc3039e-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__kasan_check_read+0x0/0x20
Code: b8 8d 48 89 de e8 70 4e 04 ff 31 ed eb cf cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 89 f6 48 8b 0c 24 31 d2 e9 ef e4 ff ff 66 66 66 66 66
RSP: 0018:ffffc90004dcf878 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff8de16840 RCX: ffffffff8b71260c
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff8de16840
RBP: ffffc90004dcf978 R08: ffffffff8de16843 R09: 1ffffffff1bc2d08
R10: dffffc0000000000 R11: fffffbfff1bc2d09 R12: 1ffff920009b9f18
R13: 0000000000000001 R14: ffffc90004dcf8e0 R15: 1ffffffff1bc2d08
FS:  0000555577e9e500(0000) GS:ffff8880b861f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efcd18e56e8 CR3: 00000000270fa000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 native_queued_spin_lock_slowpath+0xbc/0x8e0
 queued_spin_lock_slowpath+0x43/0x50
 do_raw_spin_lock+0x21f/0x290
 insert_inode_locked+0xe3/0x410
 __ext4_new_inode+0x2c91/0x3c50
 ext4_mkdir+0x3cb/0xc50
 vfs_mkdir+0x306/0x510
 do_mkdirat+0x247/0x590
 __x64_sys_mkdir+0x6c/0x80
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efcd0bc2617
Code: 44 00 00 48 8d 50 ff 83 c1 01 48 21 d0 75 f4 01 cf 48 83 c6 08 4c 39 c6 75 d9 89 f8 c3 31 ff 89 f8 c3 90 b8 53 00 00 00 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:00007fff246bba68 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007fff246bbbb2 RCX: 00007efcd0bc2617
RDX: 000000000d995ac1 RSI: 00000000000001c0 RDI: 00007fff246bbba0
RBP: f49998db0aa753ff R08: 0000000000000004 R09: 0000000000000001
R10: 3fffffffffffffff R11: 0000000000000246 R12: 8421084210842109
R13: 00007fff246bbbb2 R14: 00007efcd0c4e5a0 R15: 000000000d995ac1
 </TASK>
CPU: 1 UID: 0 PID: 7591 Comm: syz.2.514 Not tainted 6.16.0-rc6-syzkaller-00411-g95993dc3039e-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:kfree+0x190/0x440
Code: 85 c0 0f 85 c4 01 00 00 45 84 ed 0f 85 07 01 00 00 c1 ed 09 83 e5 01 41 0f b6 d5 4c 89 e7 48 89 de 89 e9 e8 02 c2 0a 00 84 c0 <75> 3d 48 8b 5c 24 08 65 48 8b 05 39 ba 87 10 49 8b 0c 24 48 8b 54
RSP: 0018:ffffc900001e0b50 EFLAGS: 00000202
RAX: 0f6947aa0295c401 RBX: ffff88811095d040 RCX: 0f6947aa0295c400
RDX: 0000000000000002 RSI: ffffffff8d99883e RDI: ffffffff8be29f40
RBP: 0000000000000000 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: ffff88801a441780
R13: 0000000000000000 R14: ffffffff821919f0 R15: ffffea0004425740
FS:  00007fc03ed506c0(0000) GS:ffff8881a3c1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000004 CR3: 0000000106892000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 slab_free_after_rcu_debug+0x60/0x2a0
 rcu_core+0xca8/0x1710
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_irq_work+0xa3/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_irq_work+0x1a/0x20
RIP: 0010:rcu_read_unlock_special+0x87/0x4c0
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 62 2c f8 10 41 f7 c6 00 00 f0 00 74 49 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90004edf720 EFLAGS: 00000206
RAX: 0f6947aa0295c400 RBX: 1ffff920009dbeec RCX: 0f6947aa0295c400
RDX: 0000000000000006 RSI: ffffffff8d99883e RDI: ffffffff8be29f40
RBP: ffffc90004edf810 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: ffffffff8e144400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000002
 __rcu_read_unlock+0x84/0xe0
 find_inode_fast+0x3a6/0x470
 iget_locked+0x11b/0x570
 kernfs_get_inode+0x4f/0x780
 kernfs_iop_lookup+0x1f6/0x320
 path_openat+0x1101/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc03df8e9a9
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:00007fc03ed50038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fc03e1b5fa0 RCX: 00007fc03df8e9a9
RDX: 000000000000275a RSI: 0000200000000040 RDI: 0000000000000007
RBP: 00007fc03e010d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc03e1b5fa0 R15: 00007ffe29bf0748
 </TASK>
sched: DL replenish lagged too much
