loop1: detected capacity change from 0 to 512
EXT4-fs: Journaled quota options ignored when QUOTA feature is enabled
EXT4-fs (loop1): mounted filesystem 007f0000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
==================================================================
BUG: KCSAN: data-race in data_push_tail / string

write to 0xffffffff895c2658 of 1 bytes by task 23261 on cpu 1:
 string_nocheck lib/vsprintf.c:652 [inline]
 string+0x165/0x220 lib/vsprintf.c:730
 vsnprintf+0x543/0x8c0 lib/vsprintf.c:2945
 vscnprintf+0x41/0x90 lib/vsprintf.c:3014
 printk_sprint+0x30/0x2b0 kernel/printk/printk.c:2222
 vprintk_store+0x57f/0x910 kernel/printk/printk.c:2364
 vprintk_emit+0x1a4/0x610 kernel/printk/printk.c:2455
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2504
 addrtype_mt_checkentry_v1+0x13b/0x160 net/netfilter/xt_addrtype.c:208
 xt_checkentry_match net/netfilter/x_tables.c:543 [inline]
 xt_check_match+0x3b7/0x5e0 net/netfilter/x_tables.c:576
 check_match net/ipv6/netfilter/ip6_tables.c:488 [inline]
 find_check_match net/ipv6/netfilter/ip6_tables.c:505 [inline]
 find_check_entry net/ipv6/netfilter/ip6_tables.c:556 [inline]
 translate_table+0xbd5/0x1210 net/ipv6/netfilter/ip6_tables.c:733
 do_replace net/ipv6/netfilter/ip6_tables.c:1152 [inline]
 do_ip6t_set_ctl+0x73e/0x990 net/ipv6/netfilter/ip6_tables.c:1643
 nf_setsockopt+0x199/0x1b0 net/netfilter/nf_sockopt.c:101
 ipv6_setsockopt+0x11a/0x130 net/ipv6/ipv6_sockglue.c:970
 tcp_setsockopt+0x98/0xb0 net/ipv4/tcp.c:4179
 sock_common_setsockopt+0x69/0x80 net/core/sock.c:4033
 do_sock_setsockopt net/socket.c:2393 [inline]
 __sys_setsockopt+0x184/0x200 net/socket.c:2418
 __do_sys_setsockopt net/socket.c:2424 [inline]
 __se_sys_setsockopt net/socket.c:2421 [inline]
 __x64_sys_setsockopt+0x64/0x80 net/socket.c:2421
 x64_sys_call+0x248f/0x2550 arch/x86/include/generated/asm/syscalls_64.h:55
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff895c2658 of 8 bytes by task 23191 on cpu 0:
 data_make_reusable kernel/printk/printk_ringbuffer.c:608 [inline]
 data_push_tail+0x104/0x440 kernel/printk/printk_ringbuffer.c:693
 data_alloc+0x111/0x380 kernel/printk/printk_ringbuffer.c:1089
 prb_reserve+0x8e3/0xaf0 kernel/printk/printk_ringbuffer.c:1727
 vprintk_store+0x54e/0x910 kernel/printk/printk.c:2354
 vprintk_emit+0x1a4/0x610 kernel/printk/printk.c:2455
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2504
 __ext4_msg+0x1aa/0x1c0 fs/ext4/super.c:1001
 ext4_fill_super+0x2f25/0x3770 fs/ext4/super.c:5851
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1887
 get_tree_bdev+0x1f/0x30 fs/super.c:1910
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5868
 vfs_get_tree+0x57/0x1d0 fs/super.c:1947
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3772 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3848
 path_mount+0x4ad/0xb90 fs/namespace.c:4168
 do_mount fs/namespace.c:4181 [inline]
 __do_sys_mount fs/namespace.c:4397 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4374
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4374
 x64_sys_call+0xc3b/0x2550 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x3fffffffffffff1d -> 0x484f525020367670

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 23191 Comm: syz.1.5683 Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
==================================================================
ext4 filesystem being mounted at /510/file1 supports timestamps until 2038-01-19 (0x7fffffff)