loop0: detected capacity change from 0 to 512 ================================================================== BUG: KCSAN: data-race in data_push_tail / number write to 0xffffffff88b5eaf7 of 1 bytes by task 6208 on cpu 0: number+0x7d0/0xa90 lib/vsprintf.c:564 vsnprintf+0xa44/0xe30 lib/vsprintf.c:2890 vscnprintf+0x42/0x90 lib/vsprintf.c:2930 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2165 vprintk_store+0x570/0x810 kernel/printk/printk.c:2279 vprintk_emit+0x10c/0x5e0 kernel/printk/printk.c:2329 vprintk_default+0x26/0x30 kernel/printk/printk.c:2363 vprintk+0x75/0x80 kernel/printk/printk_safe.c:45 _printk+0x7a/0xa0 kernel/printk/printk.c:2373 set_capacity_and_notify+0xff/0x160 block/genhd.c:86 loop_set_size+0x2e/0x70 drivers/block/loop.c:232 loop_configure+0x8b9/0xa40 drivers/block/loop.c:1102 lo_ioctl+0x5fc/0x11d0 blkdev_ioctl+0x35f/0x450 block/ioctl.c:676 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xd3/0x150 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 read to 0xffffffff88b5eaf0 of 8 bytes by task 6211 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:2269 vprintk_emit+0x10c/0x5e0 kernel/printk/printk.c:2329 vprintk_default+0x26/0x30 kernel/printk/printk.c:2363 vprintk+0x75/0x80 kernel/printk/printk_safe.c:45 _printk+0x7a/0xa0 kernel/printk/printk.c:2373 set_capacity_and_notify+0xff/0x160 block/genhd.c:86 loop_set_size+0x2e/0x70 drivers/block/loop.c:232 loop_configure+0x8b9/0xa40 drivers/block/loop.c:1102 lo_ioctl+0x5fc/0x11d0 blkdev_ioctl+0x35f/0x450 block/ioctl.c:676 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xd3/0x150 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: 0x00000000ffffe600 -> 0x742030206d6f7266 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 6211 Comm: syz.0.737 Not tainted 6.11.0-rc1-syzkaller-00334-ga5dbd76a8942 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 ================================================================== /dev/loop0: Can't open blockdev EXT4-fs: Cannot change quota options when quota turned on ext4 filesystem being remounted at /110/bus supports timestamps until 2038-01-19 (0x7fffffff) EXT4-fs error (device loop0): ext4_acquire_dquot:6848: comm syz.0.737: Failed to acquire dquot type 1 EXT4-fs error (device loop0): ext4_lookup:1815: inode #2: comm syz.0.737: deleted inode referenced: 12 EXT4-fs error (device loop0): ext4_lookup:1815: inode #2: comm syz.0.737: deleted inode referenced: 12