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BUG: KCSAN: data-race in probe_sched_switch / tracing_start_sched_switch

write to 0xffffffff895d81a0 of 4 bytes by task 10568 on cpu 1:
 tracing_start_sched_switch+0x8d/0x200 kernel/trace/trace_sched_switch.c:101
 tracing_start_cmdline_record+0x13/0x20 kernel/trace/trace_sched_switch.c:135
 __ftrace_event_enable_disable+0x203/0x4b0 kernel/trace/trace_events.c:867
 ftrace_event_enable_disable kernel/trace/trace_events.c:907 [inline]
 __ftrace_set_clr_event_nolock+0x3a1/0x820 kernel/trace/trace_events.c:1377
 __ftrace_set_clr_event kernel/trace/trace_events.c:1410 [inline]
 ftrace_set_clr_event+0x2a8/0x320 kernel/trace/trace_events.c:1460
 ftrace_event_write+0x170/0x1d0 kernel/trace/trace_events.c:1548
 vfs_write+0x254/0x9a0 fs/read_write.c:685
 ksys_write+0xdc/0x1a0 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:747
 x64_sys_call+0x154e/0x2550 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff895d81a0 of 4 bytes by task 2980 on cpu 0:
 probe_sched_switch+0x46/0xa0 kernel/trace/trace_sched_switch.c:32
 __traceiter_sched_switch+0x3f/0x60 include/trace/events/sched.h:220
 __do_trace_sched_switch include/trace/events/sched.h:220 [inline]
 trace_sched_switch include/trace/events/sched.h:220 [inline]
 __schedule+0xc31/0xd20 kernel/sched/core.c:7236
 preempt_schedule_irq+0x2c/0x50 kernel/sched/core.c:7561
 raw_irqentry_exit_cond_resched+0x49/0x60 kernel/entry/common.c:145
 irqentry_exit_to_kernel_mode_preempt+0x2b/0x40 include/linux/irq-entry-common.h:468
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x7d/0x610 kernel/entry/common.c:167
 sysvec_apic_timer_interrupt+0x44/0x80 arch/x86/kernel/apic/apic.c:1062
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
 __tsan_read4+0x12/0x190 kernel/kcsan/core.c:1024
 avtab_search_node+0x49/0x2b0 security/selinux/ss/avtab.c:154
 context_struct_compute_av+0x347/0xae0 security/selinux/ss/services.c:662
 security_compute_av+0x360/0xa30 security/selinux/ss/services.c:1178
 avc_compute_av+0x5d/0x420 security/selinux/avc.c:992
 avc_perm_nonode+0x5e/0xe0 security/selinux/avc.c:1117
 avc_has_perm_noaudit+0xea/0x120 security/selinux/avc.c:1160
 selinux_inode_permission+0x4bc/0x740 security/selinux/hooks.c:3280
 security_inode_permission+0x69/0xa0 security/security.c:1842
 lookup_inode_permission_may_exec fs/namei.c:698 [inline]
 may_lookup fs/namei.c:1961 [inline]
 link_path_walk+0x1eb/0xdd0 fs/namei.c:2604
 path_openat+0xe7/0x10d0 fs/namei.c:4996
 do_file_open+0x16c/0x290 fs/namei.c:5029
 do_sys_openat2+0xa0/0x130 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_openat fs/open.c:1439 [inline]
 __se_sys_openat fs/open.c:1434 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1434
 x64_sys_call+0x1f72/0x2550 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000092f -> 0x00000930

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 2980 Comm: udevd Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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