BUG: KCSAN: data-race in data_alloc / prb_reserve write to 0xffffffff86882558 of 8 bytes by task 29 on cpu 1: data_alloc+0x27d/0x2b0 kernel/printk/printk_ringbuffer.c:1096 prb_reserve+0x808/0xaf0 kernel/printk/printk_ringbuffer.c:1669 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2326 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2475 kauditd_printk_skb kernel/audit.c:546 [inline] kauditd_hold_skb+0x1b1/0x1c0 kernel/audit.c:581 kauditd_send_queue+0x270/0x2c0 kernel/audit.c:766 kauditd_thread+0x421/0x630 kernel/audit.c:890 kthread+0x489/0x510 kernel/kthread.c:464 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read to 0xffffffff86882558 of 8 bytes by task 19890 on cpu 0: desc_read kernel/printk/printk_ringbuffer.c:482 [inline] desc_push_tail kernel/printk/printk_ringbuffer.c:778 [inline] desc_reserve kernel/printk/printk_ringbuffer.c:924 [inline] prb_reserve+0x221/0xaf0 kernel/printk/printk_ringbuffer.c:1619 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2326 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2475 printk_stack_address arch/x86/kernel/dumpstack.c:72 [inline] show_trace_log_lvl+0x4e3/0x560 arch/x86/kernel/dumpstack.c:284 __dump_stack+0x1d/0x30 lib/dump_stack.c:94 dump_stack_lvl+0xe8/0x140 lib/dump_stack.c:120 dump_stack+0x15/0x1b lib/dump_stack.c:129 fail_dump lib/fault-inject.c:73 [inline] should_fail_ex+0x265/0x280 lib/fault-inject.c:174 should_failslab+0x8c/0xb0 mm/failslab.c:46 slab_pre_alloc_hook mm/slub.c:4100 [inline] slab_alloc_node mm/slub.c:4176 [inline] __do_kmalloc_node mm/slub.c:4326 [inline] __kmalloc_noprof+0xa5/0x3e0 mm/slub.c:4339 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] bpf_test_init+0xa9/0x160 net/bpf/test_run.c:667 bpf_prog_test_run_xdp+0x274/0x8f0 net/bpf/test_run.c:1260 bpf_prog_test_run+0x20a/0x390 kernel/bpf/syscall.c:4427 __sys_bpf+0x3dc/0x790 kernel/bpf/syscall.c:5852 __do_sys_bpf kernel/bpf/syscall.c:5941 [inline] __se_sys_bpf kernel/bpf/syscall.c:5939 [inline] __x64_sys_bpf+0x41/0x50 kernel/bpf/syscall.c:5939 x64_sys_call+0x2478/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd0/0x1a0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00000000001612d8 -> 0x0000000000203e80 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 19890 Comm: syz.1.17077 Not tainted 6.15.0-rc6-syzkaller-00085-gc94d59a126cb #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 ================================================================== bpf_prog_test_run_xdp+0x274/0x8f0 net/bpf/test_run.c:1260 bpf_prog_test_run+0x20a/0x390 kernel/bpf/syscall.c:4427 __sys_bpf+0x3dc/0x790 kernel/bpf/syscall.c:5852 __do_sys_bpf kernel/bpf/syscall.c:5941 [inline] __se_sys_bpf kernel/bpf/syscall.c:5939 [inline] __x64_sys_bpf+0x41/0x50 kernel/bpf/syscall.c:5939 x64_sys_call+0x2478/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd0/0x1a0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb0daf1e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb0d9587038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fb0db145fa0 RCX: 00007fb0daf1e969 RDX: 0000000000000048 RSI: 0000200000000600 RDI: 000000000000000a RBP: 00007fb0d9587090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 00007fb0db145fa0 R15: 00007ffc659301a8