EXT4-fs error (device loop6): ext4_mb_release_inode_pa:5366: group 0, ================================================================== BUG: KCSAN: data-race in data_alloc / data_push_tail write to 0xffffffff88e544d8 of 8 bytes by task 10 on cpu 0: data_alloc+0x215/0x2c0 kernel/printk/printk_ringbuffer.c:1082 prb_reserve+0x86a/0xb80 kernel/printk/printk_ringbuffer.c:1669 vprintk_store+0x552/0x860 kernel/printk/printk.c:2326 vprintk_emit+0x1a0/0x6c0 kernel/printk/printk.c:2426 dev_vprintk_emit+0x24a/0x2a0 drivers/base/core.c:4891 dev_printk_emit+0x84/0xb0 drivers/base/core.c:4902 __dev_printk+0xf6/0x110 drivers/base/core.c:4914 _dev_warn+0x9e/0xd0 drivers/base/core.c:4958 hid_parser_main+0x6f4/0x750 drivers/hid/hid-core.c:-1 hid_open_report+0x543/0x7c0 drivers/hid/hid-core.c:1328 hid_parse include/linux/hid.h:1126 [inline] hid_generic_probe+0x33/0x70 drivers/hid/hid-generic.c:66 __hid_device_probe drivers/hid/hid-core.c:2717 [inline] hid_device_probe+0x259/0x440 drivers/hid/hid-core.c:2754 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x1cf/0x5d0 drivers/base/dd.c:658 __driver_probe_device+0x12d/0x200 drivers/base/dd.c:800 driver_probe_device+0x38/0x2f0 drivers/base/dd.c:830 __device_attach_driver+0x216/0x320 drivers/base/dd.c:958 bus_for_each_drv+0x1cf/0x250 drivers/base/bus.c:462 __device_attach+0x1d6/0x2b0 drivers/base/dd.c:1030 device_initial_probe+0x1a/0x20 drivers/base/dd.c:1079 bus_probe_device+0x141/0x1d0 drivers/base/bus.c:537 device_add+0x5e2/0x790 drivers/base/core.c:3666 hid_add_device+0x26e/0x2f0 drivers/hid/hid-core.c:2900 uhid_device_add_worker+0x2b/0xa0 drivers/hid/uhid.c:73 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x4de/0xa20 kernel/workqueue.c:3319 worker_thread+0x52c/0x710 kernel/workqueue.c:3400 kthread+0x4b7/0x540 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 0xffffffff88e544d8 of 8 bytes by task 6395 on cpu 1: data_make_reusable kernel/printk/printk_ringbuffer.c:594 [inline] data_push_tail+0x107/0x440 kernel/printk/printk_ringbuffer.c:679 data_realloc kernel/printk/printk_ringbuffer.c:1143 [inline] prb_reserve_in_last+0x794/0xc30 kernel/printk/printk_ringbuffer.c:1440 vprintk_store+0x47a/0x860 kernel/printk/printk.c:2300 vprintk_emit+0x1a0/0x6c0 kernel/printk/printk.c:2426 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x7f/0xb0 kernel/printk/printk.c:2475 __ext4_grp_locked_error+0x5fa/0x810 fs/ext4/super.c:1058 ext4_mb_release_inode_pa+0x5b2/0x600 fs/ext4/mballoc.c:5365 ext4_mb_discard_group_preallocations+0x69a/0x880 fs/ext4/mballoc.c:5491 ext4_mb_discard_preallocations fs/ext4/mballoc.c:6025 [inline] ext4_mb_discard_preallocations_should_retry+0xee/0x4c0 fs/ext4/mballoc.c:6046 ext4_mb_new_blocks+0x1c15/0x2020 fs/ext4/mballoc.c:6245 ext4_new_meta_blocks+0xc3/0x1b0 fs/ext4/balloc.c:750 ext4_ext_grow_indepth fs/ext4/extents.c:1329 [inline] ext4_ext_create_new_leaf fs/ext4/extents.c:1433 [inline] ext4_ext_insert_extent+0xa53/0x2ad0 fs/ext4/extents.c:2115 ext4_split_extent_at+0x613/0x9f0 fs/ext4/extents.c:3252 ext4_split_extent+0x134/0x3b0 fs/ext4/extents.c:3374 ext4_split_convert_extents fs/ext4/extents.c:3740 [inline] ext4_ext_handle_unwritten_extents fs/ext4/extents.c:3912 [inline] ext4_ext_map_blocks+0xbc2/0x36a0 fs/ext4/extents.c:4271 ext4_map_create_blocks fs/ext4/inode.c:519 [inline] ext4_map_blocks+0x5f8/0xdf0 fs/ext4/inode.c:705 mpage_map_one_extent fs/ext4/inode.c:2223 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2276 [inline] ext4_do_writepages+0x14ef/0x21d0 fs/ext4/inode.c:2738 ext4_writepages+0x183/0x320 fs/ext4/inode.c:2828 do_writepages+0x1d8/0x480 mm/page-writeback.c:2656 filemap_fdatawrite_wbc mm/filemap.c:386 [inline] __filemap_fdatawrite_range mm/filemap.c:419 [inline] file_write_and_wait_range+0x16e/0x2f0 mm/filemap.c:794 generic_buffers_fsync_noflush+0x46/0x120 fs/buffer.c:600 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline] ext4_sync_file+0x1c3/0x6c0 fs/ext4/fsync.c:147 vfs_fsync_range+0x116/0x130 fs/sync.c:187 generic_write_sync include/linux/fs.h:2976 [inline] ext4_buffered_write_iter+0x358/0x3c0 fs/ext4/file.c:305 ext4_file_write_iter+0x3b2/0xf80 include/linux/fs.h:-1 do_iter_readv_writev+0x40d/0x4b0 fs/read_write.c:-1 vfs_writev+0x2da/0x880 fs/read_write.c:1055 do_pwritev fs/read_write.c:1151 [inline] __do_sys_pwritev2 fs/read_write.c:1209 [inline] __se_sys_pwritev2+0x103/0x1d0 fs/read_write.c:1200 __x64_sys_pwritev2+0x78/0x90 fs/read_write.c:1200 x64_sys_call+0x1c86/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:329 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00000000ffffe62c -> 0x00000000fffff25c Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 6395 Comm: syz.6.1013 Not tainted 6.15.0-rc1-syzkaller-00095-g2eb959eeecc6 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 ================================================================== free 0, pa_free 8 EXT4-fs (loop6): Delayed block allocation failed for inode 15 at logical offset 3 with max blocks 1 with error 28 EXT4-fs (loop6): This should not happen!! Data will be lost EXT4-fs (loop6): Total free blocks count 0 EXT4-fs (loop6): Free/Dirty block details EXT4-fs (loop6): free_blocks=128 EXT4-fs (loop6): dirty_blocks=0 EXT4-fs (loop6): Block reservation details EXT4-fs (loop6): i_reserved_data_blocks=0 syz.6.1013 (6395) used greatest stack depth: 6936 bytes left