loop2: detected capacity change from 0 to 512
==================================================================
BUG: KCSAN: data-race in data_push_tail / number

write to 0xffffffff86e23184 of 1 bytes by task 23766 on cpu 1:
 number+0x7d0/0xa90 lib/vsprintf.c:562
 vsnprintf+0xa44/0xe20 lib/vsprintf.c:2862
 vscnprintf+0x42/0x80 lib/vsprintf.c:2902
 printk_sprint+0x30/0x330 kernel/printk/printk.c:2180
 vprintk_store+0x56e/0x800 kernel/printk/printk.c:2294
 vprintk_emit+0xd0/0x430 kernel/printk/printk.c:2340
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2370
 vprintk+0x83/0x90 kernel/printk/printk_safe.c:50
 _printk+0x7a/0xa0 kernel/printk/printk.c:2380
 set_capacity_and_notify+0x178/0x1d0 block/genhd.c:90
 loop_set_size+0x2e/0x70 drivers/block/loop.c:237
 loop_configure+0xafb/0xc20 drivers/block/loop.c:1100
 lo_ioctl+0x688/0x12f0
 blkdev_ioctl+0x3a4/0x490 block/ioctl.c:616
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xc9/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffffffff86e23180 of 8 bytes by task 23767 on cpu 0:
 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+0x893/0xbc0 kernel/printk/printk_ringbuffer.c:1555
 vprintk_store+0x53d/0x800 kernel/printk/printk.c:2284
 vprintk_emit+0xd0/0x430 kernel/printk/printk.c:2340
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2370
 vprintk+0x83/0x90 kernel/printk/printk_safe.c:50
 _printk+0x7a/0xa0 kernel/printk/printk.c:2380
 set_capacity_and_notify+0x178/0x1d0 block/genhd.c:90
 loop_set_size+0x2e/0x70 drivers/block/loop.c:237
 loop_configure+0xafb/0xc20 drivers/block/loop.c:1100
 lo_ioctl+0x688/0x12f0
 blkdev_ioctl+0x3a4/0x490 block/ioctl.c:616
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xc9/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x000000010000ccc2 -> 0x0a3231323135206f

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 23767 Comm: syz-executor.2 Not tainted 6.2.0-rc7-syzkaller-00199-g420b2d431d18-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
==================================================================
[EXT4 FS bs=4096, gc=1, bpg=95, ipg=32, mo=b85ee098, mo2=0000]
System zones: 
0-1, 18-18, 34-34, 40-40

EXT4-fs error (device loop2): mb_free_blocks:1780: group 0, 
inode 16: 
block 39:freeing already freed block (bit 39); block bitmap corrupt.
EXT4-fs (loop2): 1 orphan inode deleted
EXT4-fs (loop2): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: writeback.
ext4 filesystem being mounted at /root/syzkaller-testdir2404617595/syzkaller.D7jUWk/3511/file1 supports timestamps until 2038 (0x7fffffff)