syzbot

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BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff868a4558 of 88 bytes by task 3399 on cpu 1:
 prb_reserve+0x696/0xaf0 kernel/printk/printk_ringbuffer.c:1635
 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2326
 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426
 dev_vprintk_emit+0x242/0x2a0 drivers/base/core.c:4917
 dev_printk_emit+0x84/0xb0 drivers/base/core.c:4928
 __dev_printk+0xf3/0x110 drivers/base/core.c:4940
 _dev_warn+0x9b/0xd0 drivers/base/core.c:4984
 hid_parser_main+0x6ff/0x750 drivers/hid/hid-core.c:-1
 hid_open_report+0x48e/0x7a0 drivers/hid/hid-core.c:1328
 hid_parse include/linux/hid.h:1133 [inline]
 hid_generic_probe+0x33/0x70 drivers/hid/hid-generic.c:66
 __hid_device_probe drivers/hid/hid-core.c:2724 [inline]
 hid_device_probe+0x2c5/0x490 drivers/hid/hid-core.c:2761
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x1bf/0x5a0 drivers/base/dd.c:657
 __driver_probe_device+0x121/0x190 drivers/base/dd.c:799
 driver_probe_device+0x37/0x2f0 drivers/base/dd.c:829
 __device_attach_driver+0x205/0x310 drivers/base/dd.c:957
 bus_for_each_drv+0x1c0/0x230 drivers/base/bus.c:462
 __device_attach+0x1c7/0x290 drivers/base/dd.c:1029
 device_initial_probe+0x1a/0x30 drivers/base/dd.c:1078
 bus_probe_device+0x143/0x1d0 drivers/base/bus.c:537
 device_add+0x5c9/0x770 drivers/base/core.c:3692
 hid_add_device+0x273/0x2f0 drivers/hid/hid-core.c:2907
 uhid_device_add_worker+0x2b/0xa0 drivers/hid/uhid.c:73
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x486/0x510 kernel/kthread.c:464
 ret_from_fork+0xdd/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff868a4558 of 8 bytes by task 2985 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:486 [inline]
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1874 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1922 [inline]
 _prb_read_valid+0x1c4/0x920 kernel/printk/printk_ringbuffer.c:2113
 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2185
 syslog_print+0x23a/0x540 kernel/printk/printk.c:1650
 do_syslog+0x52b/0x7e0 kernel/printk/printk.c:1785
 __do_sys_syslog kernel/printk/printk.c:1877 [inline]
 __se_sys_syslog kernel/printk/printk.c:1875 [inline]
 __x64_sys_syslog+0x41/0x50 kernel/printk/printk.c:1875
 x64_sys_call+0x2ea0/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:104
 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: 0x0000000000002205 -> 0x0000000000004205

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 2985 Comm: klogd Not tainted 6.16.0-rc2-syzkaller-00231-g75f5f23f8787 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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