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BUG: KCSAN: data-race in data_alloc / prb_reserve

write to 0xffffffff85c62178 of 8 bytes by task 29492 on cpu 0:
 data_alloc+0x291/0x2c0 kernel/printk/printk_ringbuffer.c:1088
 prb_reserve+0x897/0xbc0 kernel/printk/printk_ringbuffer.c:1555
 vprintk_store+0x53e/0x800 kernel/printk/printk.c:2228
 vprintk_emit+0xd0/0x5d0 kernel/printk/printk.c:2284
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2318
 vprintk+0x71/0x80 kernel/printk/printk_safe.c:45
 _printk+0x7a/0xa0 kernel/printk/printk.c:2328
 __netdev_printk+0x2dc/0x3f0 net/core/dev.c:11489
 netdev_info+0x99/0xc0 net/core/dev.c:11536
 __dev_set_promiscuity+0x189/0x370 net/core/dev.c:8439
 dev_set_promiscuity+0x3b/0x90 net/core/dev.c:8477
 packet_dev_mc net/packet/af_packet.c:3632 [inline]
 packet_flush_mclist net/packet/af_packet.c:3760 [inline]
 packet_release+0x2fb/0x7e0 net/packet/af_packet.c:3151
 __sock_release net/socket.c:659 [inline]
 sock_close+0x64/0x140 net/socket.c:1421
 __fput+0x299/0x630 fs/file_table.c:376
 __fput_sync+0x44/0x50 fs/file_table.c:461
 __do_sys_close fs/open.c:1554 [inline]
 __se_sys_close+0xfa/0x1a0 fs/open.c:1539
 __x64_sys_close+0x1f/0x30 fs/open.c:1539
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffffffff85c62178 of 8 bytes by task 29488 on cpu 1:
 desc_read kernel/printk/printk_ringbuffer.c:478 [inline]
 desc_push_tail kernel/printk/printk_ringbuffer.c:774 [inline]
 desc_reserve kernel/printk/printk_ringbuffer.c:920 [inline]
 prb_reserve+0x229/0xbc0 kernel/printk/printk_ringbuffer.c:1505
 vprintk_store+0x53e/0x800 kernel/printk/printk.c:2228
 vprintk_emit+0xd0/0x5d0 kernel/printk/printk.c:2284
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2318
 vprintk+0x71/0x80 kernel/printk/printk_safe.c:45
 _printk+0x7a/0xa0 kernel/printk/printk.c:2328
 base_sock_release+0x38/0x200 drivers/isdn/mISDN/socket.c:622
 __sock_release net/socket.c:659 [inline]
 sock_close+0x64/0x140 net/socket.c:1421
 __fput+0x299/0x630 fs/file_table.c:376
 ____fput+0x15/0x20 fs/file_table.c:404
 task_work_run+0x135/0x1a0 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x604/0x16d0 kernel/exit.c:871
 do_group_exit+0x101/0x150 kernel/exit.c:1020
 get_signal+0xf4e/0x10a0 kernel/signal.c:2893
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:105 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline]
 syscall_exit_to_user_mode+0x58/0x120 kernel/entry/common.c:212
 do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00000000001306a0 -> 0x0000000000199f38

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 29488 Comm: syz-executor.1 Not tainted 6.8.0-rc7-syzkaller-00017-g29cd507cbec2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
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