syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P27554/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=201361, q=185 ncpus=2)
task:syz.3.6676      state:R  running task     stack:24104 pid:27554 tgid:27554 ppid:5820   task_flags:0x400640 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x10e9/0x6820 kernel/sched/core.c:7188
 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512
 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline]
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
 irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:task_css include/linux/cgroup.h:521 [inline]
RIP: 0010:mem_cgroup_from_task mm/memcontrol.c:1080 [inline]
RIP: 0010:get_mem_cgroup_from_mm+0xa4/0x5c0 mm/memcontrol.c:1133
Code: 00 00 e8 ef 7a 1a 09 85 c0 0f 85 a0 00 00 00 48 85 db 0f 84 e6 00 00 00 48 8d bb f8 13 00 00 48 89 f8 48 c1 e8 03 80 3c 28 00 <0f> 85 34 04 00 00 4c 8b bb f8 13 00 00 e8 ba 7a 1a 09 85 c0 0f 85
RSP: 0018:ffffc9000e446b58 EFLAGS: 00000246
RAX: 1ffff1100dcd171f RBX: ffff88806e68a500 RCX: 0000000000000001
RDX: 0000000000000046 RSI: ffffffff8df341ae RDI: ffff88806e68b8f8
RBP: dffffc0000000000 R08: 00000000bdda7ede R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: ffff8880365524c0
R13: ffffed1006caa5e6 R14: ffffffff827fb709 R15: 0000000000000000
 __mem_cgroup_charge+0x1a/0x1c0 mm/memcontrol.c:5022
 mem_cgroup_charge include/linux/memcontrol.h:644 [inline]
 shmem_alloc_and_add_folio+0x451/0xd40 mm/shmem.c:1985
 shmem_get_folio_gfp+0x6ab/0x1900 mm/shmem.c:2564
 shmem_get_folio mm/shmem.c:2670 [inline]
 shmem_write_begin+0x1a4/0x420 mm/shmem.c:3303
 generic_perform_write+0x292/0xa40 mm/filemap.c:4325
 shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3478
 __kernel_write_iter+0x2ac/0x920 fs/read_write.c:621
 dump_emit_page fs/coredump.c:1304 [inline]
 dump_user_range+0x3f9/0xad0 fs/coredump.c:1378
 elf_core_dump+0x2d5f/0x3d10 fs/binfmt_elf.c:2109
 coredump_write fs/coredump.c:1053 [inline]
 do_coredump fs/coredump.c:1132 [inline]
 vfs_coredump+0x29a0/0x5770 fs/coredump.c:1206
 get_signal+0x1f2a/0x21e0 kernel/signal.c:3022
 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:252 [inline]
 irqentry_exit_to_user_mode include/linux/irq-entry-common.h:323 [inline]
 irqentry_exit+0x403/0x790 kernel/entry/common.c:162
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f3d5b4527f7
RSP: 002b:00007f3d5c48e1a0 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007f3d5b59c819
RDX: 00007f3d5c48e1c0 RSI: 00007f3d5c48e2f0 RDI: 000000000000000b
RBP: 00007f3d5b632c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f3d5b816038 R14: 00007f3d5b815fa0 R15: 00007ffea3ccccb8
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g201361 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=106772
rcu: rcu_preempt kthread starved for 10502 jiffies! g201361 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26472 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x10e9/0x6820 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7282
 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </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: 27556 Comm: syz.2.6678 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 56 5b 5c 00 48 89 df 5b e9 7d e6 61 00 be 03 00 00 00 5b e9 62 4b f0 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 65 8b 05 45 a5 0a 12 48 8b 34 24 65 48 8b 15 21 a5 0a
RSP: 0018:ffffc90000007e38 EFLAGS: 00000046
RAX: 0000000000010001 RBX: ffff88807a0ed300 RCX: 0000000000000001
RDX: ffff88806a72ca00 RSI: ffffffff81f5489e RDI: ffff8880b8428504
RBP: ffff8880b8428600 R08: 0000000000000005 R09: 000000000000001f
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: ffff8880b84284c0 R14: 0000000000000000 R15: 00000000fffffffd
FS:  00007f11fcae76c0(0000) GS:ffff8881242de000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000ca030 CR3: 000000004f0d7000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 timerqueue_linked_first include/linux/timerqueue.h:48 [inline]
 base_update_next_timer kernel/time/hrtimer.c:1126 [inline]
 __remove_hrtimer+0x1cc/0x440 kernel/time/hrtimer.c:1162
 __run_hrtimer kernel/time/hrtimer.c:1910 [inline]
 __hrtimer_run_queues+0x359/0xa00 kernel/time/hrtimer.c:1994
 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872
Code: 05 3b c2 2e 12 83 f8 07 0f 87 d9 02 00 00 48 0f a3 05 46 b8 f6 0e 0f 82 a4 02 00 00 8b 35 ce eb f6 0e 85 f6 0f 85 bf 00 00 00 <48> 8b 44 24 30 65 48 2b 05 dd c1 2e 12 0f 85 ed 02 00 00 48 83 c4
RSP: 0018:ffffc9000e437638 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8df341ae RDI: ffffffff8c1c1f80
RBP: ffffffff8e7e5460 R08: 00000000dacd92cc R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 rcu_read_lock include/linux/rcupdate.h:838 [inline]
 mt_find+0x14a/0x8e0 lib/maple_tree.c:6269
 find_vma+0xbf/0x140 mm/mmap.c:908
 lock_mm_and_find_vma+0x62/0x6f0 mm/mmap_lock.c:504
 do_user_addr_fault+0x29a/0x12f0 arch/x86/mm/fault.c:1357
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:__put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:104
Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca e9 87 d7 03 00 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 01 cb <89> 01 31 c9 0f 01 ca c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000e4379d8 EFLAGS: 00050246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00002000000ca030
RDX: 0000000000080000 RSI: ffffffff895cb2a1 RDI: ffff88806a72ca00
RBP: ffffc9000e437d78 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
R13: 00002000000ca000 R14: ffffc9000e437dbc R15: 0000000000000002
 ____sys_recvmsg+0x2ec/0x640 net/socket.c:2931
 ___sys_recvmsg+0x16a/0x1a0 net/socket.c:2960
 do_recvmmsg+0x301/0x760 net/socket.c:3055
 __sys_recvmmsg net/socket.c:3129 [inline]
 __do_sys_recvmmsg net/socket.c:3152 [inline]
 __se_sys_recvmmsg net/socket.c:3145 [inline]
 __x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3145
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f11fbb9c819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f11fcae7028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f11fbe15fa0 RCX: 00007f11fbb9c819
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f11fbc32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f11fbe16038 R14: 00007f11fbe15fa0 R15: 00007ffcf3691368
 </TASK>