================================================================== BUG: KCSAN: data-race in do_sys_poll / pollwake read to 0xffffc9000cd43bd0 of 4 bytes by task 9375 on cpu 1: poll_schedule_timeout fs/select.c:240 [inline] do_poll fs/select.c:962 [inline] do_sys_poll+0x986/0xc10 fs/select.c:1013 __do_sys_ppoll fs/select.c:1119 [inline] __se_sys_ppoll+0x1af/0x1f0 fs/select.c:1099 __x64_sys_ppoll+0x67/0x80 fs/select.c:1099 x64_sys_call+0xe71/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:272 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f write to 0xffffc9000cd43bd0 of 4 bytes by interrupt on cpu 0: __pollwake fs/select.c:195 [inline] pollwake+0xbe/0x110 fs/select.c:215 __wake_up_common kernel/sched/wait.c:89 [inline] __wake_up_common_lock kernel/sched/wait.c:106 [inline] __wake_up+0x65/0xb0 kernel/sched/wait.c:127 bpf_ringbuf_notify+0x22/0x30 kernel/bpf/ringbuf.c:154 irq_work_single kernel/irq_work.c:221 [inline] irq_work_run_list kernel/irq_work.c:252 [inline] irq_work_run+0xdf/0x2c0 kernel/irq_work.c:261 __sysvec_irq_work+0x23/0x1a0 arch/x86/kernel/irq_work.c:22 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x2f/0x80 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738 native_apic_mem_write arch/x86/include/asm/apic.h:101 [inline] __default_send_IPI_shortcut arch/x86/kernel/apic/ipi.c:166 [inline] default_send_IPI_self+0x38/0x80 arch/x86/kernel/apic/ipi.c:247 __apic_send_IPI_self arch/x86/include/asm/apic.h:455 [inline] arch_irq_work_raise+0x48/0x50 arch/x86/kernel/irq_work.c:31 irq_work_raise kernel/irq_work.c:84 [inline] __irq_work_queue_local+0x82/0x1d0 kernel/irq_work.c:112 irq_work_queue+0x85/0x120 kernel/irq_work.c:124 ____bpf_ringbuf_discard kernel/bpf/ringbuf.c:532 [inline] bpf_ringbuf_discard+0xcd/0xf0 kernel/bpf/ringbuf.c:530 bpf_prog_fe0ed97373b08409+0x46/0x4a bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2406 [inline] bpf_trace_run3+0x10c/0x1d0 kernel/trace/bpf_trace.c:2448 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x238/0x2d0 mm/slub.c:4681 radix_tree_node_rcu_free+0x56/0x60 lib/radix-tree.c:304 rcu_do_batch kernel/rcu/tree.c:2567 [inline] rcu_core+0x57b/0xbc0 kernel/rcu/tree.c:2823 rcu_core_si+0xd/0x20 kernel/rcu/tree.c:2840 handle_softirqs+0xbf/0x280 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0x3e/0x90 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline] sysvec_apic_timer_interrupt+0x73/0x80 arch/x86/kernel/apic/apic.c:1037 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:94 [inline] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irq+0x2f/0x50 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] filemap_remove_folio+0x73/0x1f0 mm/filemap.c:265 truncate_inode_folio+0x42/0x50 mm/truncate.c:178 shmem_undo_range+0x25e/0xa50 mm/shmem.c:1019 shmem_truncate_range mm/shmem.c:1132 [inline] shmem_evict_inode+0x14d/0x530 mm/shmem.c:1260 evict+0x2f0/0x580 fs/inode.c:731 iput_final fs/inode.c:1883 [inline] iput+0x42a/0x5b0 fs/inode.c:1909 dentry_unlink_inode+0x24f/0x260 fs/dcache.c:412 __dentry_kill+0x18b/0x4c0 fs/dcache.c:615 dput+0x5c/0xd0 fs/dcache.c:857 __fput+0x3fb/0x6d0 fs/file_table.c:439 ____fput+0x1c/0x30 fs/file_table.c:459 task_work_run+0x13a/0x1a0 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x5dd/0x1720 kernel/exit.c:882 do_group_exit+0x102/0x150 kernel/exit.c:1031 get_signal+0xfc8/0x1100 kernel/signal.c:2936 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] irqentry_exit_to_user_mode+0x9a/0x130 kernel/entry/common.c:231 irqentry_exit+0x12/0x50 kernel/entry/common.c:334 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 value changed: 0x00000001 -> 0x00000000 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 9280 Comm: syz.4.2656 Not tainted 6.11.0-syzkaller-07262-g839c4f596f89 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 ================================================================== GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog