==================================================================
BUG: KCSAN: data-race in __bpf_get_stackid / __bpf_get_stackid

write to 0xffff888109aabcc4 of 4 bytes by task 7106 on cpu 0:
 __bpf_get_stackid+0x77a/0x800 kernel/bpf/stackmap.c:292
 ____bpf_get_stackid kernel/bpf/stackmap.c:324 [inline]
 bpf_get_stackid+0xe9/0x120 kernel/bpf/stackmap.c:300
 ____bpf_get_stackid_raw_tp kernel/trace/bpf_trace.c:1628 [inline]
 bpf_get_stackid_raw_tp+0xf6/0x120 kernel/trace/bpf_trace.c:1617
 bpf_prog_53f0063d4d7f65ce+0x2a/0x32
 bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline]
 __bpf_prog_run include/linux/filter.h:721 [inline]
 bpf_prog_run include/linux/filter.h:728 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
 bpf_trace_run2+0x107/0x1c0 kernel/trace/bpf_trace.c:2116
 __do_trace_kfree include/trace/events/kmem.h:97 [inline]
 trace_kfree include/trace/events/kmem.h:97 [inline]
 kfree+0x351/0x400 mm/slub.c:6805
 check_cfg+0xfad/0x1240 kernel/bpf/verifier.c:17980
 bpf_check+0xa1b2/0xd9d0 kernel/bpf/verifier.c:24619
 bpf_prog_load+0xf6e/0x1100 kernel/bpf/syscall.c:3062
 __sys_bpf+0x469/0x7c0 kernel/bpf/syscall.c:6134
 __do_sys_bpf kernel/bpf/syscall.c:6244 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6242 [inline]
 __x64_sys_bpf+0x41/0x50 kernel/bpf/syscall.c:6242
 x64_sys_call+0x2aee/0x3000 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888109aabcc4 of 4 bytes by task 7078 on cpu 1:
 __bpf_get_stackid+0x33a/0x800 kernel/bpf/stackmap.c:278
 ____bpf_get_stackid kernel/bpf/stackmap.c:324 [inline]
 bpf_get_stackid+0xe9/0x120 kernel/bpf/stackmap.c:300
 ____bpf_get_stackid_raw_tp kernel/trace/bpf_trace.c:1628 [inline]
 bpf_get_stackid_raw_tp+0xf6/0x120 kernel/trace/bpf_trace.c:1617
 bpf_prog_53f0063d4d7f65ce+0x2a/0x32
 bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline]
 __bpf_prog_run include/linux/filter.h:721 [inline]
 bpf_prog_run include/linux/filter.h:728 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
 bpf_trace_run2+0x107/0x1c0 kernel/trace/bpf_trace.c:2116
 __do_trace_kfree include/trace/events/kmem.h:97 [inline]
 trace_kfree include/trace/events/kmem.h:97 [inline]
 kfree+0x351/0x400 mm/slub.c:6805
 io_req_alloc_apoll io_uring/poll.c:651 [inline]
 io_arm_apoll+0x1b1/0x420 io_uring/poll.c:680
 io_arm_poll_handler+0x131/0x160 io_uring/poll.c:716
 io_queue_async+0x25d/0x2d0 io_uring/io_uring.c:2055
 io_queue_sqe io_uring/io_uring.c:2081 [inline]
 io_req_task_submit+0xf6/0x100 io_uring/io_uring.c:1466
 io_handle_tw_list+0x190/0x1c0 io_uring/io_uring.c:1151
 tctx_task_work_run+0x6d/0x1a0 io_uring/io_uring.c:1216
 tctx_task_work+0x3f/0x80 io_uring/io_uring.c:1234
 task_work_run+0x131/0x1a0 kernel/task_work.c:227
 get_signal+0xe12/0xf70 kernel/signal.c:2807
 arch_do_signal_or_restart+0x96/0x440 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x77/0x110 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x1d6/0x200 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000011 -> 0x0000000c

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 7078 Comm: syz.4.1445 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
==================================================================