loop4: detected capacity change from 0 to 1024
==================================================================
BUG: KCSAN: data-race in data_alloc / prb_reserve

write to 0xffffffff86677e18 of 8 bytes by task 14154 on cpu 1:
 data_alloc+0x291/0x2c0 kernel/printk/printk_ringbuffer.c:1096
 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
 dev_vprintk_emit+0x1df/0x210 drivers/base/core.c:4912
 dev_printk_emit+0x82/0xb0 drivers/base/core.c:4923
 __dev_printk+0xf6/0x110 drivers/base/core.c:4935
 _dev_err+0x99/0xc0 drivers/base/core.c:4978
 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:599 [inline]
 raw_ioctl+0x18ab/0x1b50 drivers/usb/gadget/legacy/raw_gadget.c:1306
 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 0xffffffff86677e18 of 8 bytes by task 14153 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:482 [inline]
 desc_push_tail kernel/printk/printk_ringbuffer.c:778 [inline]
 desc_reserve kernel/printk/printk_ringbuffer.c:924 [inline]
 prb_reserve+0x235/0xb60 kernel/printk/printk_ringbuffer.c:1619
 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
 __ext4_msg+0x134/0x1a0 fs/ext4/super.c:992
 ext4_parse_param+0x839/0xf40 fs/ext4/super.c:2186
 vfs_parse_fs_param+0x13b/0x290 fs/fs_context.c:146
 vfs_parse_fs_string fs/fs_context.c:188 [inline]
 vfs_parse_monolithic_sep fs/fs_context.c:230 [inline]
 generic_parse_monolithic+0x165/0x1d0 fs/fs_context.c:258
 parse_monolithic_mount_data+0x43/0x50 fs/fs_context.c:719
 do_new_mount+0x1fa/0x690 fs/namespace.c:3468
 path_mount+0x49b/0xb30 fs/namespace.c:3799
 do_mount fs/namespace.c:3812 [inline]
 __do_sys_mount fs/namespace.c:4020 [inline]
 __se_sys_mount+0x27c/0x2d0 fs/namespace.c:3997
 __x64_sys_mount+0x67/0x80 fs/namespace.c:3997
 x64_sys_call+0x203e/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:166
 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: 0x0000000000002470 -> 0x00000000000a0b30

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 14153 Comm: syz.4.3265 Not tainted 6.11.0-rc3-syzkaller-00013-g6b0f8db921ab #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
==================================================================
EXT4-fs: Ignoring removed orlov option
EXT4-fs: Ignoring removed nomblk_io_submit option
EXT4-fs (loop4): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.