================================================================== BUG: KCSAN: data-race in data_alloc / prb_reserve write to 0xffffffff8686b990 of 8 bytes by task 12528 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 __ext4_msg+0x18f/0x1a0 fs/ext4/super.c:981 ext4_print_free_blocks fs/ext4/inode.c:1758 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2429 [inline] ext4_do_writepages+0x1a52/0x21c0 fs/ext4/inode.c:2863 ext4_writepages+0x176/0x300 fs/ext4/inode.c:2953 do_writepages+0x1c6/0x310 mm/page-writeback.c:2636 filemap_fdatawrite_wbc mm/filemap.c:386 [inline] __filemap_fdatawrite_range mm/filemap.c:419 [inline] file_write_and_wait_range+0x156/0x2c0 mm/filemap.c:794 generic_buffers_fsync_noflush+0x45/0x120 fs/buffer.c:609 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline] ext4_sync_file+0x1ab/0x690 fs/ext4/fsync.c:147 vfs_fsync_range+0x10a/0x130 fs/sync.c:187 generic_write_sync include/linux/fs.h:3029 [inline] ext4_buffered_write_iter+0x34f/0x3c0 fs/ext4/file.c:305 ext4_file_write_iter+0x383/0xf00 fs/ext4/file.c:-1 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x4a0/0x8e0 fs/read_write.c:686 ksys_write+0xda/0x1a0 fs/read_write.c:738 __do_sys_write fs/read_write.c:749 [inline] __se_sys_write fs/read_write.c:746 [inline] __x64_sys_write+0x40/0x50 fs/read_write.c:746 x64_sys_call+0x2cdd/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:2 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 read to 0xffffffff8686b990 of 8 bytes by task 3390 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 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+0x48b/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+0x2c8/0x490 drivers/hid/hid-core.c:2761 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x1bc/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+0xda/0x150 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 value changed: 0xfffffffffffc7158 -> 0x0000000000060f88 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 3390 Comm: kworker/0:3 Not tainted 6.16.0-rc1-syzkaller-00239-g08215f5486ec #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events uhid_device_add_worker ================================================================== hid-generic 0000:0000:0000.0024: unknown main item tag 0x0 hid-generic 0000:0000:0000.0024: hidraw0: HID v0.00 Device [syz1] on syz0