loop2: detected capacity change from 0 to 2048
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BUG: KCSAN: data-race in data_push_tail / string

write to 0xffffffff88b9e26a of 1 bytes by task 26870 on cpu 0:
 string_nocheck lib/vsprintf.c:650 [inline]
 string+0x16c/0x210 lib/vsprintf.c:728
 vsnprintf+0xa09/0xe30 lib/vsprintf.c:2803
 vscnprintf+0x42/0x90 lib/vsprintf.c:2909
 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2197
 vprintk_store+0x570/0x810 kernel/printk/printk.c:2311
 vprintk_emit+0x15e/0x680 kernel/printk/printk.c:2383
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2422
 vprintk+0x75/0x80 kernel/printk/printk_safe.c:68
 _printk+0x7a/0xa0 kernel/printk/printk.c:2432
 __ext4_warning_inode+0x17c/0x190 fs/ext4/super.c:1033
 ext4_empty_dir+0x239/0x5a0 fs/ext4/namei.c:3098
 ext4_rmdir+0x1b4/0x600 fs/ext4/namei.c:3173
 vfs_rmdir+0x270/0x320 fs/namei.c:4340
 do_rmdir+0x194/0x320 fs/namei.c:4399
 __do_sys_unlinkat fs/namei.c:4575 [inline]
 __se_sys_unlinkat fs/namei.c:4569 [inline]
 __x64_sys_unlinkat+0xa2/0xb0 fs/namei.c:4569
 x64_sys_call+0x25fd/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:264
 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 0xffffffff88b9e268 of 8 bytes by task 29846 on cpu 1:
 data_make_reusable kernel/printk/printk_ringbuffer.c:594 [inline]
 data_push_tail+0x102/0x430 kernel/printk/printk_ringbuffer.c:679
 data_alloc+0xbe/0x2c0 kernel/printk/printk_ringbuffer.c:1054
 prb_reserve+0x85e/0xb60 kernel/printk/printk_ringbuffer.c:1669
 vprintk_store+0x53f/0x810 kernel/printk/printk.c:2301
 vprintk_emit+0x15e/0x680 kernel/printk/printk.c:2383
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2422
 vprintk+0x75/0x80 kernel/printk/printk_safe.c:68
 _printk+0x7a/0xa0 kernel/printk/printk.c:2432
 set_capacity_and_notify+0xff/0x160 block/genhd.c:86
 loop_set_size+0x2e/0x70 drivers/block/loop.c:232
 loop_configure+0x8a7/0xa30 drivers/block/loop.c:1102
 lo_ioctl+0x5f6/0x11c0
 blkdev_ioctl+0x359/0x450 block/ioctl.c:693
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xcd/0x140 fs/ioctl.c:893
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:893
 x64_sys_call+0x15cc/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:17
 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

value changed: 0x0000000100000fdb -> 0x203a2931706f6f6c

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 29846 Comm: syz.2.6684 Tainted: G        W          6.12.0-rc3-syzkaller-00183-g6efbea77b390 #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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