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BUG: KCSAN: data-race in __rb_reserve_next / ring_buffer_iter_peek

write to 0xffff88811dd0a000 of 8 bytes by task 9682 on cpu 1:
 __rb_reserve_next+0x5e9/0x6c0 kernel/trace/ring_buffer.c:4906
 rb_reserve_next_event kernel/trace/ring_buffer.c:4980 [inline]
 ring_buffer_lock_reserve+0x6b3/0x860 kernel/trace/ring_buffer.c:5039
 __trace_buffer_lock_reserve kernel/trace/trace.h:1676 [inline]
 trace_event_buffer_lock_reserve+0x14a/0x300 kernel/trace/trace.c:1924
 trace_event_buffer_reserve+0x120/0x180 kernel/trace/trace_events.c:715
 do_trace_event_raw_event_sys_enter include/trace/events/syscalls.h:18 [inline]
 trace_event_raw_event_sys_enter+0x6b/0x1f0 include/trace/events/syscalls.h:18
 __do_trace_sys_enter include/trace/events/syscalls.h:18 [inline]
 trace_sys_enter include/trace/events/syscalls.h:18 [inline]
 trace_syscall_enter+0xc4/0x110 kernel/entry/syscall-common.c:13
 syscall_trace_enter include/linux/entry-common.h:103 [inline]
 syscall_enter_from_user_mode_work include/linux/entry-common.h:140 [inline]
 do_syscall_64+0x295/0x360 arch/x86/entry/syscall_64.c:81
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811dd0a000 of 8 bytes by task 9488 on cpu 0:
 ring_buffer_iter_empty kernel/trace/ring_buffer.c:5702 [inline]
 rb_iter_peek kernel/trace/ring_buffer.c:6197 [inline]
 ring_buffer_iter_peek+0x265/0xb10 kernel/trace/ring_buffer.c:6359
 peek_next_entry kernel/trace/trace.c:2349 [inline]
 __find_next_entry+0x1a9/0x420 kernel/trace/trace.c:2398
 trace_find_next_entry_inc kernel/trace/trace.c:2672 [inline]
 s_next+0x10e/0x370 kernel/trace/trace.c:2711
 traverse+0x1c1/0x3b0 fs/seq_file.c:121
 seq_read_iter+0x7dc/0x8f0 fs/seq_file.c:196
 do_iter_readv_writev+0x4f6/0x5a0 fs/read_write.c:-1
 vfs_readv+0x1e8/0x6d0 fs/read_write.c:1019
 do_preadv fs/read_write.c:1133 [inline]
 __do_sys_preadv2 fs/read_write.c:1192 [inline]
 __se_sys_preadv2+0xfc/0x1c0 fs/read_write.c:1183
 __x64_sys_preadv2+0x67/0x80 fs/read_write.c:1183
 x64_sys_call+0x1dc5/0x2550 arch/x86/include/generated/asm/syscalls_64.h:328
 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: 0x000000422156409a -> 0x000000422e30973d

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 9488 Comm: syz.3.1619 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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