syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=71e4/1/0x4000000000000000 softirq=12318/12318 fqs=2
	(detected by 1, t=10502 jiffies, g=13845, q=242 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5228 Comm: syz.3.315 Not tainted 6.1.140-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__lock_acquire+0x1051/0x7c50 kernel/locking/lockdep.c:5044
Code: 41 01 d6 29 da 41 89 dc 41 c1 c4 04 41 31 d4 48 c7 c0 e8 b4 fe 8d 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 b4 5a 00 00 41 01 de <83> 3d c0 b5 9b 0c 00 4c 8b bc 24 c0 00 00 00 0f 85 02 03 00 00 48
RSP: 0018:ffffc900000078e0 EFLAGS: 00000007
RAX: 0000000000000000 RBX: 000000007ae82481 RCX: 0000000036266ac9
RDX: 0000000074ac2974 RSI: 0000000000104b6c RDI: ffffffff908b8240
RBP: ffffc90000007b30 R08: dffffc0000000000 R09: fffffbfff2117049
R10: fffffbfff2117049 R11: 1ffffffff2117048 R12: 00000000da2e6163
R13: 000000000000402d R14: 0000000034457c0f R15: ffff88807db66468
FS:  00007ff5758526c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4021d80178 CR3: 00000000291b4000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 advance_sched+0x6e8/0x970 net/sched/sch_taprio.c:753
 __run_hrtimer kernel/time/hrtimer.c:1691 [inline]
 __hrtimer_run_queues+0x522/0xc80 kernel/time/hrtimer.c:1755
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1817
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 2e f7 6d f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> b6 71 3e f7 65 8b 05 57 33 e9 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc9000548e9a0 EFLAGS: 00000206
RAX: 26d86c9081007300 RBX: 0000000000000a02 RCX: 26d86c9081007300
RDX: dffffc0000000000 RSI: ffffffff8a6c0000 RDI: 0000000000000001
RBP: ffffc9000548ea20 R08: dffffc0000000000 R09: fffffbfff2117059
R10: fffffbfff2117059 R11: 1ffffffff2117058 R12: dffffc0000000000
R13: ffffc9001be00000 R14: ffffffff96c8ffc8 R15: 1ffff92000a91d34
 __debug_check_no_obj_freed lib/debugobjects.c:988 [inline]
 debug_check_no_obj_freed+0x515/0x530 lib/debugobjects.c:1009
 __vunmap+0x27a/0xa00 mm/vmalloc.c:2699
 __vfree mm/vmalloc.c:2767 [inline]
 __vmalloc_area_node mm/vmalloc.c:3118 [inline]
 __vmalloc_node_range+0x10b1/0x1390 mm/vmalloc.c:3235
 kvmalloc_node+0x13b/0x180 mm/util.c:606
 hash_netiface_create+0x35d/0xfe0 net/netfilter/ipset/ip_set_hash_gen.h:1515
 ip_set_create+0xa83/0x1850 net/netfilter/ipset/ip_set_core.c:1111
 nfnetlink_rcv_msg+0xb45/0x1120 net/netfilter/nfnetlink.c:302
 netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2493
 nfnetlink_rcv+0x26d/0x2170 net/netfilter/nfnetlink.c:659
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0x74c/0x8c0 net/netlink/af_netlink.c:1337
 netlink_sendmsg+0x89e/0xbc0 net/netlink/af_netlink.c:1859
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x59b/0x970 net/socket.c:2519
 ___sys_sendmsg+0x21c/0x290 net/socket.c:2573
 __sys_sendmsg net/socket.c:2602 [inline]
 __do_sys_sendmsg net/socket.c:2611 [inline]
 __se_sys_sendmsg+0x19e/0x270 net/socket.c:2609
 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: 0033:0x7ff57498e969
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:00007ff575852038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff574bb5fa0 RCX: 00007ff57498e969
RDX: 0000000000000800 RSI: 0000200000000040 RDI: 0000000000000004
RBP: 00007ff574a10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff574bb5fa0 R15: 00007ffe7709c978
 </TASK>
rcu: rcu_preempt kthread starved for 10498 jiffies! g13845 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:27200 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
 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: 4561 Comm: kworker/u4:10 Not tainted 6.1.140-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:check_kcov_mode kernel/kcov.c:193 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x32/0x60 kernel/kcov.c:216
Code: 24 98 81 7e 65 8b 15 25 98 81 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 <83> fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc
RSP: 0018:ffffc900054f6518 EFLAGS: 00000246
RAX: ffffffff8175f132 RBX: dffffc0000000000 RCX: ffff888019f75940
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900054f6680 R08: dffffc0000000000 R09: ffffed10171e7763
R10: ffffed10171e7763 R11: 1ffff110171e7762 R12: 1ffff110171c85a5
R13: ffff8880b8f3bb00 R14: 0000000000000000 R15: ffff8880b8e42d28
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4021c121e6 CR3: 000000005b931000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:424 [inline]
 smp_call_function_many_cond+0xe92/0x1270 kernel/smp.c:998
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:970 [inline]
 flush_tlb_mm_range+0x409/0x610 arch/x86/mm/tlb.c:1058
 flush_tlb_page arch/x86/include/asm/tlbflush.h:241 [inline]
 ptep_clear_flush+0x11c/0x160 mm/pgtable-generic.c:98
 page_vma_mkclean_one+0x400/0x680 mm/rmap.c:970
 page_mkclean_one+0x1d6/0x370 mm/rmap.c:1018
 rmap_walk_file+0x3e8/0x730 mm/rmap.c:2511
 rmap_walk mm/rmap.c:2529 [inline]
 folio_mkclean+0x1c4/0x330 mm/rmap.c:1050
 folio_clear_dirty_for_io+0x20a/0xc30 mm/page-writeback.c:2886
 mpage_submit_page+0x8a/0x210 fs/ext4/inode.c:2122
 mpage_process_page_bufs+0x6d8/0x8b0 fs/ext4/inode.c:2256
 mpage_prepare_extent_to_map+0xaf4/0x15d0 fs/ext4/inode.c:2681
 ext4_writepages+0xa22/0x2e50 fs/ext4/inode.c:2809
 do_writepages+0x3b7/0x610 mm/page-writeback.c:2491
 __writeback_single_inode+0x156/0x1160 fs/fs-writeback.c:1612
 writeback_sb_inodes+0xad8/0x17d0 fs/fs-writeback.c:1903
 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:1974
 wb_writeback+0x47a/0xd00 fs/fs-writeback.c:2079
 wb_check_old_data_flush fs/fs-writeback.c:2179 [inline]
 wb_do_writeback fs/fs-writeback.c:2232 [inline]
 wb_workfn+0xb66/0xec0 fs/fs-writeback.c:2260
 process_one_work+0x898/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>