EXT4-fs (loop2): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback. ================================================================== BUG: KCSAN: data-race in _prb_read_valid / data_alloc write to 0xffffffff868799d8 of 8 bytes by task 10671 on cpu 0: data_alloc+0x271/0x2b0 kernel/printk/printk_ringbuffer.c:1095 prb_reserve+0x808/0xaf0 kernel/printk/printk_ringbuffer.c:1669 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2326 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2475 __ext4_error+0x248/0x320 fs/ext4/super.c:813 ext4_release_dquot+0x2e7/0x460 fs/ext4/super.c:6967 quota_release_workfn+0x256/0x530 fs/quota/dquot.c:840 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321 worker_thread+0x582/0x770 kernel/workqueue.c:3402 kthread+0x486/0x510 kernel/kthread.c:464 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read to 0xffffffff868799d8 of 16 bytes by task 13817 on cpu 1: desc_read kernel/printk/printk_ringbuffer.c:482 [inline] desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1874 [inline] prb_read kernel/printk/printk_ringbuffer.c:1922 [inline] _prb_read_valid+0x1bc/0x920 kernel/printk/printk_ringbuffer.c:2113 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2185 __console_flush_and_unlock kernel/printk/printk.c:3304 [inline] console_unlock+0x164/0x330 kernel/printk/printk.c:3325 vprintk_emit+0x388/0x650 kernel/printk/printk.c:2450 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2475 __ext4_msg+0x18f/0x1a0 fs/ext4/super.c:981 ext4_fill_super+0x2d05/0x34e0 fs/ext4/super.c:5739 get_tree_bdev_flags+0x291/0x300 fs/super.c:1679 get_tree_bdev+0x1f/0x30 fs/super.c:1702 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5756 vfs_get_tree+0x54/0x1d0 fs/super.c:1802 do_new_mount+0x207/0x680 fs/namespace.c:3856 path_mount+0x4a4/0xb20 fs/namespace.c:4180 do_mount fs/namespace.c:4193 [inline] __do_sys_mount fs/namespace.c:4404 [inline] __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4381 __x64_sys_mount+0x67/0x80 fs/namespace.c:4381 x64_sys_call+0xd36/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 13817 Comm: syz.2.3744 Not tainted 6.15.0-syzkaller-13659-g5b032cac6225 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 ================================================================== ext4 filesystem being mounted at /153/file1 supports timestamps until 2038-01-19 (0x7fffffff)