EXT4-fs error (device loop6): ext4_mb_generate_buddy:1220: group 0, 
==================================================================
BUG: KCSAN: data-race in data_push_tail / number

write to 0xffffffff88bcbca4 of 1 bytes by task 19257 on cpu 1:
 number+0x7f0/0xac0 lib/vsprintf.c:551
 vsnprintf+0x6ae/0x890 lib/vsprintf.c:2807
 vscnprintf+0x42/0x90 lib/vsprintf.c:2908
 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2216
 vprintk_store+0x589/0x870 kernel/printk/printk.c:2336
 vprintk_emit+0x15e/0x680 kernel/printk/printk.c:2408
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2447
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x7a/0xa0 kernel/printk/printk.c:2457
 dump_stack_print_info+0xdf/0x1a0 lib/dump_stack.c:57
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0xe6/0x150 lib/dump_stack.c:120
 dump_stack+0x15/0x1a lib/dump_stack.c:129
 fail_dump lib/fault-inject.c:73 [inline]
 should_fail_ex+0x24a/0x260 lib/fault-inject.c:174
 should_failslab+0x8f/0xb0 mm/failslab.c:46
 slab_pre_alloc_hook mm/slub.c:4068 [inline]
 slab_alloc_node mm/slub.c:4144 [inline]
 kmem_cache_alloc_noprof+0x52/0x320 mm/slub.c:4171
 mpol_new mm/mempolicy.c:332 [inline]
 do_mbind mm/mempolicy.c:1299 [inline]
 kernel_mbind mm/mempolicy.c:1537 [inline]
 __do_sys_mbind mm/mempolicy.c:1611 [inline]
 __se_sys_mbind+0x415/0x11c0 mm/mempolicy.c:1607
 __x64_sys_mbind+0x78/0x90 mm/mempolicy.c:1607
 x64_sys_call+0x2662/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:238
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff88bcbca0 of 8 bytes by task 11448 on cpu 0:
 data_make_reusable kernel/printk/printk_ringbuffer.c:594 [inline]
 data_push_tail+0x102/0x430 kernel/printk/printk_ringbuffer.c:679
 data_realloc kernel/printk/printk_ringbuffer.c:1143 [inline]
 prb_reserve_in_last+0x773/0xc10 kernel/printk/printk_ringbuffer.c:1440
 vprintk_store+0x47b/0x870 kernel/printk/printk.c:2300
 vprintk_emit+0x15e/0x680 kernel/printk/printk.c:2408
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2447
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x7a/0xa0 kernel/printk/printk.c:2457
 __ext4_grp_locked_error+0x5b0/0x7b0 fs/ext4/super.c:1071
 ext4_mb_generate_buddy+0x247/0x2d0 fs/ext4/mballoc.c:1217
 ext4_mb_init_cache+0x848/0xbc0 fs/ext4/mballoc.c:1406
 ext4_mb_init_group+0x210/0x3b0 fs/ext4/mballoc.c:1543
 ext4_mb_good_group_nolock fs/ext4/mballoc.c:2704 [inline]
 ext4_mb_regular_allocator+0xc2a/0x23a0 fs/ext4/mballoc.c:2903
 ext4_mb_new_blocks+0x801/0x2020 fs/ext4/mballoc.c:6217
 ext4_ext_map_blocks+0x1008/0x35c0 fs/ext4/extents.c:4379
 ext4_map_create_blocks fs/ext4/inode.c:516 [inline]
 ext4_map_blocks+0x5aa/0xd20 fs/ext4/inode.c:702
 mpage_map_one_extent fs/ext4/inode.c:2219 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2272 [inline]
 ext4_do_writepages+0xd68/0x2130 fs/ext4/inode.c:2735
 ext4_writepages+0x159/0x2e0 fs/ext4/inode.c:2824
 do_writepages+0x1d8/0x480 mm/page-writeback.c:2687
 __writeback_single_inode+0x89/0x850 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x461/0xa30 fs/fs-writeback.c:1976
 wb_writeback+0x262/0x640 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x1a8/0x940 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3317
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3398
 kthread+0x4ae/0x520 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x00000000fffffaa2 -> 0x00000000203a4449

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 11448 Comm: kworker/u8:7 Not tainted 6.13.0-syzkaller-09383-gebbb8be421ee #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: writeback wb_workfn (flush-7:6)
==================================================================
block bitmap and bg descriptor inconsistent: 25 vs 4278190105 free clusters
EXT4-fs (loop6): Delayed block allocation failed for inode 18 at logical offset 0 with max blocks 2048 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=68451041280
EXT4-fs (loop6): dirty_blocks=2704
EXT4-fs (loop6): Block reservation details
EXT4-fs (loop6): i_reserved_data_blocks=169