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BUG: KCSAN: data-race in __bpf_get_stackid / __bpf_get_stackid

write to 0xffff88811dd68868 of 4 bytes by interrupt on cpu 0:
 __bpf_get_stackid+0x76b/0x800 kernel/bpf/stackmap.c:291
 ____bpf_get_stackid kernel/bpf/stackmap.c:324 [inline]
 bpf_get_stackid+0xee/0x120 kernel/bpf/stackmap.c:300
 ____bpf_get_stackid_raw_tp kernel/trace/bpf_trace.c:1810 [inline]
 bpf_get_stackid_raw_tp+0xf6/0x120 kernel/trace/bpf_trace.c:1799
 bpf_prog_e6fc920cfeff8120+0x2a/0x32
 bpf_dispatcher_nop_func include/linux/bpf.h:1332 [inline]
 __bpf_prog_run include/linux/filter.h:718 [inline]
 bpf_prog_run include/linux/filter.h:725 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2257 [inline]
 bpf_trace_run3+0x10f/0x1d0 kernel/trace/bpf_trace.c:2299
 __do_trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
 kmem_cache_free+0x257/0x300 mm/slub.c:4781
 free_signal_struct kernel/fork.c:724 [inline]
 put_signal_struct kernel/fork.c:730 [inline]
 __put_task_struct+0x1f3/0x2e0 kernel/fork.c:747
 __put_task_struct_rcu_cb+0x1c/0x30 kernel/fork.c:757
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0x5aa/0xc30 kernel/rcu/tree.c:2861
 rcu_core_si+0xd/0x20 kernel/rcu/tree.c:2878
 handle_softirqs+0xba/0x290 kernel/softirq.c:579
 run_ksoftirqd+0x1c/0x30 kernel/softirq.c:968
 smpboot_thread_fn+0x328/0x530 kernel/smpboot.c:160
 kthread+0x486/0x510 kernel/kthread.c:463
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff88811dd68868 of 4 bytes by interrupt on cpu 1:
 __bpf_get_stackid+0x287/0x800 kernel/bpf/stackmap.c:249
 ____bpf_get_stackid kernel/bpf/stackmap.c:324 [inline]
 bpf_get_stackid+0xee/0x120 kernel/bpf/stackmap.c:300
 ____bpf_get_stackid_raw_tp kernel/trace/bpf_trace.c:1810 [inline]
 bpf_get_stackid_raw_tp+0xf6/0x120 kernel/trace/bpf_trace.c:1799
 bpf_prog_e6fc920cfeff8120+0x2a/0x32
 bpf_dispatcher_nop_func include/linux/bpf.h:1332 [inline]
 __bpf_prog_run include/linux/filter.h:718 [inline]
 bpf_prog_run include/linux/filter.h:725 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2257 [inline]
 bpf_trace_run3+0x10f/0x1d0 kernel/trace/bpf_trace.c:2299
 __do_trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
 kmem_cache_free+0x257/0x300 mm/slub.c:4781
 taskstats_tgid_free include/linux/taskstats_kern.h:22 [inline]
 free_signal_struct kernel/fork.c:716 [inline]
 put_signal_struct kernel/fork.c:730 [inline]
 __put_task_struct+0x174/0x2e0 kernel/fork.c:747
 __put_task_struct_rcu_cb+0x1c/0x30 kernel/fork.c:757
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0x5aa/0xc30 kernel/rcu/tree.c:2861
 rcu_core_si+0xd/0x20 kernel/rcu/tree.c:2878
 handle_softirqs+0xba/0x290 kernel/softirq.c:579
 run_ksoftirqd+0x1c/0x30 kernel/softirq.c:968
 smpboot_thread_fn+0x328/0x530 kernel/smpboot.c:160
 kthread+0x486/0x510 kernel/kthread.c:463
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0xe0c73803 -> 0x10d502f8

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 22 Comm: ksoftirqd/1 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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