EXT4-fs (loop3): unmounting filesystem 00000000-0000-0000-0000-000000000000.
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BUG: KCSAN: data-race in __bpf_get_stackid / bcmp

write to 0xffff88812106b898 of 112 bytes by task 28 on cpu 0:
 __bpf_get_stackid+0x761/0x800 kernel/bpf/stackmap.c:288
 ____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_run2+0x104/0x1c0 kernel/trace/bpf_trace.c:2298
 __traceiter_kfree+0x2b/0x50 include/trace/events/kmem.h:94
 __do_trace_kfree include/trace/events/kmem.h:94 [inline]
 trace_kfree include/trace/events/kmem.h:94 [inline]
 kfree+0x27b/0x320 mm/slub.c:4866
 __bpf_prog_put_noref+0xac/0x230 kernel/bpf/syscall.c:2341
 bpf_prog_put_deferred+0x1f9/0x230 kernel/bpf/syscall.c:2367
 __bpf_prog_put kernel/bpf/syscall.c:2379 [inline]
 bpf_prog_put kernel/bpf/syscall.c:2386 [inline]
 bpf_link_dealloc kernel/bpf/syscall.c:3134 [inline]
 bpf_link_defer_dealloc_rcu_gp kernel/bpf/syscall.c:3147 [inline]
 bpf_link_defer_dealloc_mult_rcu_gp+0x1dd/0x1f0 kernel/bpf/syscall.c:3153
 rcu_tasks_invoke_cbs+0x28a/0x340 kernel/rcu/tasks.h:578
 rcu_tasks_one_gp+0x891/0x8e0 kernel/rcu/tasks.h:628
 rcu_tasks_kthread+0xf7/0x110 kernel/rcu/tasks.h:658
 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 0xffff88812106b8e8 of 8 bytes by task 12171 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+0x371/0x800 kernel/bpf/stackmap.c:279
 ____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_run2+0x104/0x1c0 kernel/trace/bpf_trace.c:2298
 __traceiter_kfree+0x2b/0x50 include/trace/events/kmem.h:94
 __do_trace_kfree include/trace/events/kmem.h:94 [inline]
 trace_kfree include/trace/events/kmem.h:94 [inline]
 kfree+0x27b/0x320 mm/slub.c:4866
 context_destroy security/selinux/ss/context.h:185 [inline]
 security_compute_sid+0x11da/0x1290 security/selinux/ss/services.c:1946
 security_transition_sid+0x5a/0x70 security/selinux/ss/services.c:1968
 socket_sockcreate_sid security/selinux/hooks.c:4751 [inline]
 selinux_socket_post_create+0x254/0x2a0 security/selinux/hooks.c:4823
 security_socket_post_create+0x5d/0xb0 security/security.c:4607
 __sock_create+0x362/0x5b0 net/socket.c:1612
 sock_create net/socket.c:1647 [inline]
 __sys_socket_create net/socket.c:1684 [inline]
 __sys_socket+0xb0/0x180 net/socket.c:1731
 __do_sys_socket net/socket.c:1745 [inline]
 __se_sys_socket net/socket.c:1743 [inline]
 __x64_sys_socket+0x3f/0x50 net/socket.c:1743
 x64_sys_call+0x1147/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:42
 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

value changed: 0xffffffff844a21a0 -> 0xffffffff8148b727

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 12171 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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