==================================================================
BUG: KCSAN: data-race in data_push_tail / string

write to 0xffffffff87108ae0 of 1 bytes by task 27 on cpu 0:
 string_nocheck lib/vsprintf.c:650 [inline]
 string+0x16c/0x200 lib/vsprintf.c:728
 vsnprintf+0xa09/0xe30 lib/vsprintf.c:2824
 vscnprintf+0x42/0x80 lib/vsprintf.c:2930
 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2124
 vprintk_store+0x56f/0x800 kernel/printk/printk.c:2238
 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
 kauditd_printk_skb kernel/audit.c:546 [inline]
 kauditd_hold_skb+0x19d/0x1b0 kernel/audit.c:581
 kauditd_send_queue+0x27a/0x2d0 kernel/audit.c:766
 kauditd_thread+0x42a/0x640 kernel/audit.c:890
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

read to 0xffffffff87108ae0 of 8 bytes by task 2781 on cpu 1:
 data_make_reusable kernel/printk/printk_ringbuffer.c:590 [inline]
 data_push_tail+0x102/0x430 kernel/printk/printk_ringbuffer.c:675
 data_alloc+0xbe/0x2c0 kernel/printk/printk_ringbuffer.c:1046
 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
 __ext4_error+0x21c/0x310 fs/ext4/super.c:838
 ext4_validate_block_bitmap+0x95b/0x990 fs/ext4/balloc.c:440
 ext4_read_block_bitmap_nowait+0x40b/0x680 fs/ext4/balloc.c:556
 ext4_mb_init_cache+0x2b8/0xcd0 fs/ext4/mballoc.c:1332
 ext4_mb_init_group+0x1c4/0x5d0 fs/ext4/mballoc.c:1536
 ext4_mb_good_group_nolock fs/ext4/mballoc.c:2692 [inline]
 ext4_mb_regular_allocator+0x1c00/0x21c0 fs/ext4/mballoc.c:2890
 ext4_mb_new_blocks+0x804/0x21e0 fs/ext4/mballoc.c:6203
 ext4_ext_map_blocks+0x10a1/0x33b0 fs/ext4/extents.c:4317
 ext4_map_blocks+0x72a/0xf50 fs/ext4/inode.c:623
 ext4_getblk+0x112/0x510 fs/ext4/inode.c:833
 ext4_bread+0x2c/0x110 fs/ext4/inode.c:889
 ext4_quota_write+0x155/0x370 fs/ext4/super.c:7225
 write_blk fs/quota/quota_tree.c:64 [inline]
 do_insert_tree+0x829/0xde0 fs/quota/quota_tree.c:380
 do_insert_tree+0x4ab/0xde0 fs/quota/quota_tree.c:375
 do_insert_tree+0x4ab/0xde0 fs/quota/quota_tree.c:375
 do_insert_tree+0x4ab/0xde0 fs/quota/quota_tree.c:375
 dq_insert_tree fs/quota/quota_tree.c:401 [inline]
 qtree_write_dquot+0x241/0x2b0 fs/quota/quota_tree.c:420
 v2_write_dquot+0x9e/0xd0 fs/quota/quota_v2.c:358
 dquot_acquire+0x1c8/0x2d0 fs/quota/dquot.c:470
 ext4_acquire_dquot+0x161/0x1a0 fs/ext4/super.c:6882
 dqget+0x51c/0x880 fs/quota/dquot.c:978
 __dquot_initialize+0x263/0x750 fs/quota/dquot.c:1504
 dquot_initialize+0x1a/0x20 fs/quota/dquot.c:1562
 ext4_process_orphan+0x32/0x1c0 fs/ext4/orphan.c:329
 ext4_orphan_cleanup+0x669/0x9b0 fs/ext4/orphan.c:474
 __ext4_fill_super fs/ext4/super.c:5582 [inline]
 ext4_fill_super+0x3668/0x39b0 fs/ext4/super.c:5703
 get_tree_bdev+0x250/0x2e0 fs/super.c:1619
 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5735
 vfs_get_tree+0x53/0x1d0 fs/super.c:1784
 do_new_mount+0x227/0x690 fs/namespace.c:3352
 path_mount+0x496/0xb30 fs/namespace.c:3679
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:3875
 __x64_sys_mount+0x67/0x80 fs/namespace.c:3875
 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

value changed: 0x0000000100001d73 -> 0x2e726f7475636578

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2781 Comm: syz-executor.2 Not tainted 6.8.0-rc5-syzkaller-00297-gf2e367d6ad3b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
==================================================================
EXT4-fs (loop2): 1 truncate cleaned up
EXT4-fs (loop2): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
ext4 filesystem being mounted at /root/syzkaller-testdir2622787362/syzkaller.7sYdL5/165/file0 supports timestamps until 2038-01-19 (0x7fffffff)
syz-executor.2 (2781) used greatest stack depth: 6952 bytes left