rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4448/1:b..l
	(detected by 1, t=10502 jiffies, g=10181, q=149 ncpus=2)
task:udevd           state:R  running task     stack:23488 pid:4448  ppid:3637   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x7e/0x80 kernel/kcov.c:315
Code: 8d 52 28 4d 39 ca 77 22 89 ff 89 f6 49 ff c0 4c 89 01 48 c7 44 11 08 05 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 <c3> 90 48 8b 04 24 65 48 8b 0d 84 8b 81 7e 65 8b 15 85 8b 81 7e 81
RSP: 0018:ffffc90002e876d8 EFLAGS: 00000293
RAX: ffffffff89fe4b8f RBX: 000000000000000d RCX: 0000000000000000
RDX: ffff8880238f5940 RSI: 0000000000000300 RDI: 0000000000000300
RBP: ffffc90002e878b0 R08: ffff8880238f5940 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: ffff888079253bd0
R13: ffff888079307480 R14: ffff88807f2c0f00 R15: 0000000000000300
 mt_external_lock include/linux/maple_tree.h:561 [inline]
 mt_locked lib/maple_tree.c:809 [inline]
 mt_slot lib/maple_tree.c:816 [inline]
 mas_slot lib/maple_tree.c:849 [inline]
 mt_validate_nulls lib/maple_tree.c:7193 [inline]
 mt_validate+0x437f/0x4c90 lib/maple_tree.c:7249
 validate_mm_mt+0xcd/0x420 mm/mmap.c:295
 validate_mm+0xcc/0x2b0 mm/mmap.c:332
 mmap_region+0x780/0x1c70 mm/mmap.c:2922
 do_mmap+0x958/0xfd0 mm/mmap.c:1436
 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:520
 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: 0033:0x7fe40971d822
RSP: 002b:00007ffc3f8d8da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe40971d822
RDX: 0000000000000003 RSI: 0000000000000200 RDI: 0000000000000000
RBP: 0000000000000022 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000000022 R11: 0000000000000246 R12: 00000000000001f6
R13: 0000000000003e00 R14: 00005563fa5dd0b0 R15: 0000000000001e00
 </TASK>
rcu: rcu_preempt kthread starved for 10537 jiffies! g10181 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:26880 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 4568 Comm: syz.3.41 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__syscall_enter_from_user_work kernel/entry/common.c:97 [inline]
RIP: 0010:syscall_enter_from_user_mode+0x2a/0x80 kernel/entry/common.c:118
Code: 41 56 53 48 89 f3 49 89 fe 48 8b 7c 24 10 e8 ed fa ff ff 66 90 66 90 e8 54 ca 76 f7 e8 cf c8 76 f7 fb 65 48 8b 05 26 fc f1 75 <48> 8b 70 08 40 f6 c6 3f 74 0b 4c 89 f7 5b 41 5e e9 81 72 5d f7 48
RSP: 0018:ffffc90005217f08 EFLAGS: 00000286
RAX: ffff88801db30000 RBX: 0000000000000027 RCX: 03cfe39b1f934400
RDX: dffffc0000000000 RSI: ffffffff8a6c0600 RDI: ffffffff8abef920
RBP: ffffc90005217f48 R08: dffffc0000000000 R09: fffffbfff1bfe1c6
R10: fffffbfff1bfe1c6 R11: 1ffffffff1bfe1c5 R12: 0000000000000000
R13: 0000000000000000 R14: ffffc90005217f58 R15: 0000000000000000
FS:  00007f65ceb986c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 00000000570f9000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:77
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f65cdd865e7
Code: 0b e9 68 fe ff ff 48 83 c4 18 48 8d 3d b2 62 d9 00 5b 5d 41 5c 41 5d 41 5e 41 5f e9 23 f8 fb ff 0f 1f 00 b8 27 00 00 00 0f 05 <c3> 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00
RSP: 002b:00007f65ceb97a48 EFLAGS: 00000206 ORIG_RAX: 0000000000000027
RAX: ffffffffffffffda RBX: 00007f65ceb97bb0 RCX: 00007f65cdd865e7
RDX: 00007f65ceb97a80 RSI: 00007f65ceb97bb0 RDI: 0000000000000021
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f65cdfe6038 R14: 00007f65cdfe5fa0 R15: 00007fff9e4f6f18
 </TASK>
sched: RT throttling activated