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BUG: KCSAN: data-race in bcmp / stack_map_get_build_id_offset

read to 0xffff88810b35c010 of 8 bytes by task 7936 on cpu 1:
 memcmp lib/string.c:683 [inline]
 bcmp+0x23/0x90 lib/string.c:715
 memcmp include/linux/fortify-string.h:727 [inline]
 __bpf_get_stackid+0x648/0x7d0 kernel/bpf/stackmap.c:292
 ____bpf_get_stackid kernel/bpf/stackmap.c:344 [inline]
 bpf_get_stackid+0xf3/0x130 kernel/bpf/stackmap.c:323
 ____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_ff69ba342f4eb966+0x2a/0x32
 bpf_dispatcher_nop_func include/linux/bpf.h:1378 [inline]
 __bpf_prog_run include/linux/filter.h:723 [inline]
 bpf_prog_run include/linux/filter.h:730 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
 bpf_trace_run4+0x117/0x1e0 kernel/trace/bpf_trace.c:2118
 __do_trace_mm_page_alloc include/trace/events/kmem.h:180 [inline]
 trace_mm_page_alloc include/trace/events/kmem.h:180 [inline]
 __alloc_frozen_pages_noprof+0x336/0x360 mm/page_alloc.c:5232
 __alloc_pages_noprof+0x9/0x20 mm/page_alloc.c:5244
 __alloc_pages_node_noprof include/linux/gfp.h:285 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:312 [inline]
 bpf_ringbuf_area_alloc kernel/bpf/ringbuf.c:127 [inline]
 bpf_ringbuf_alloc+0x1ef/0x400 kernel/bpf/ringbuf.c:175
 ringbuf_map_alloc+0x1ca/0x230 kernel/bpf/ringbuf.c:218
 map_create+0x862/0xda0 kernel/bpf/syscall.c:1514
 __sys_bpf+0x54e/0x7c0 kernel/bpf/syscall.c:6146
 __do_sys_bpf kernel/bpf/syscall.c:6274 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6272 [inline]
 __x64_sys_bpf+0x41/0x50 kernel/bpf/syscall.c:6272
 x64_sys_call+0x28e1/0x3000 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xca/0x2b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff88810b35c014 of 20 bytes by task 7937 on cpu 0:
 stack_map_get_build_id_offset+0x44f/0x530 kernel/bpf/stackmap.c:183
 __bpf_get_stackid+0x60b/0x7d0 kernel/bpf/stackmap.c:289
 ____bpf_get_stackid kernel/bpf/stackmap.c:344 [inline]
 bpf_get_stackid+0xf3/0x130 kernel/bpf/stackmap.c:323
 ____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_ff69ba342f4eb966+0x2a/0x32
 bpf_dispatcher_nop_func include/linux/bpf.h:1378 [inline]
 __bpf_prog_run include/linux/filter.h:723 [inline]
 bpf_prog_run include/linux/filter.h:730 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
 bpf_trace_run4+0x117/0x1e0 kernel/trace/bpf_trace.c:2118
 __do_trace_mm_page_alloc include/trace/events/kmem.h:180 [inline]
 trace_mm_page_alloc include/trace/events/kmem.h:180 [inline]
 __alloc_frozen_pages_noprof+0x336/0x360 mm/page_alloc.c:5232
 alloc_pages_mpol+0xb3/0x260 mm/mempolicy.c:2486
 folio_alloc_mpol_noprof+0x39/0x80 mm/mempolicy.c:2505
 shmem_alloc_folio mm/shmem.c:1890 [inline]
 shmem_alloc_and_add_folio mm/shmem.c:1932 [inline]
 shmem_get_folio_gfp+0x3cf/0xd50 mm/shmem.c:2556
 shmem_fault+0xf6/0x250 mm/shmem.c:2757
 __do_fault+0xbc/0x200 mm/memory.c:5320
 do_read_fault mm/memory.c:5755 [inline]
 do_fault mm/memory.c:5889 [inline]
 do_pte_missing mm/memory.c:4401 [inline]
 handle_pte_fault mm/memory.c:6273 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0xfab/0x2c60 mm/memory.c:6580
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x1024/0x1ed0 mm/gup.c:1428
 populate_vma_page_range mm/gup.c:1860 [inline]
 __mm_populate+0x243/0x3a0 mm/gup.c:1963
 mm_populate include/linux/mm.h:3701 [inline]
 vm_mmap_pgoff+0x232/0x2e0 mm/util.c:586
 ksys_mmap_pgoff+0xc2/0x310 mm/mmap.c:604
 x64_sys_call+0x16bb/0x3000 arch/x86/include/generated/asm/syscalls_64.h:10
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xca/0x2b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 7937 Comm: syz.4.1477 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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