EXT4-fs (loop6): Delayed block allocation failed for inode 18 at logical offset 0 with max blocks 4 with error 28
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BUG: KCSAN: data-race in data_push_tail / string

write to 0xffffffff88ea82b8 of 1 bytes by task 11366 on cpu 0:
 string_nocheck lib/vsprintf.c:658 [inline]
 string+0x187/0x220 lib/vsprintf.c:736
 vsnprintf+0x532/0x860 lib/vsprintf.c:2947
 vscnprintf+0x41/0x90 lib/vsprintf.c:3012
 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2192
 vprintk_store+0x568/0x830 kernel/printk/printk.c:2312
 vprintk_emit+0x15a/0x5c0 kernel/printk/printk.c:2402
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2441
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2451
 addrtype_mt_checkentry_v1+0x1b2/0x1f0 net/netfilter/xt_addrtype.c:197
 xt_check_match+0x2ad/0x4f0 net/netfilter/x_tables.c:523
 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+0xb4b/0x1070 net/ipv6/netfilter/ip6_tables.c:733
 do_replace net/ipv6/netfilter/ip6_tables.c:1154 [inline]
 do_ip6t_set_ctl+0x678/0x840 net/ipv6/netfilter/ip6_tables.c:1644
 nf_setsockopt+0x199/0x1b0 net/netfilter/nf_sockopt.c:101
 ipv6_setsockopt+0x11a/0x130 net/ipv6/ipv6_sockglue.c:978
 tcp_setsockopt+0x98/0xb0 net/ipv4/tcp.c:4166
 sock_common_setsockopt+0x69/0x80 net/core/sock.c:3972
 do_sock_setsockopt net/socket.c:2322 [inline]
 __sys_setsockopt+0x184/0x200 net/socket.c:2347
 __do_sys_setsockopt net/socket.c:2353 [inline]
 __se_sys_setsockopt net/socket.c:2350 [inline]
 __x64_sys_setsockopt+0x64/0x80 net/socket.c:2350
 x64_sys_call+0x21d5/0x3000 arch/x86/include/generated/asm/syscalls_64.h:55
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xca/0x2b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff88ea82b8 of 8 bytes by task 10553 on cpu 1:
 data_make_reusable kernel/printk/printk_ringbuffer.c:608 [inline]
 data_push_tail+0x100/0x470 kernel/printk/printk_ringbuffer.c:693
 data_alloc+0x11b/0x390 kernel/printk/printk_ringbuffer.c:1089
 prb_reserve+0x8d7/0xad0 kernel/printk/printk_ringbuffer.c:1724
 vprintk_store+0x53c/0x830 kernel/printk/printk.c:2302
 vprintk_emit+0x15a/0x5c0 kernel/printk/printk.c:2402
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2441
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2451
 __ext4_msg+0x18f/0x1a0 fs/ext4/super.c:990
 mpage_map_and_submit_extent fs/ext4/inode.c:2499 [inline]
 ext4_do_writepages+0x1d33/0x27e0 fs/ext4/inode.c:2932
 ext4_writepages+0x179/0x300 fs/ext4/inode.c:3026
 do_writepages+0x1c6/0x310 mm/page-writeback.c:2598
 __writeback_single_inode+0x80/0x7c0 fs/fs-writeback.c:1737
 writeback_sb_inodes+0x4b0/0xb20 fs/fs-writeback.c:2030
 wb_writeback+0x252/0x5c0 fs/fs-writeback.c:2216
 wb_do_writeback fs/fs-writeback.c:2363 [inline]
 wb_workfn+0x194/0x910 fs/fs-writeback.c:2403
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3340
 worker_thread+0x582/0x770 kernel/workqueue.c:3421
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

value changed: 0x00000000ffffef54 -> 0x4249484f52502036

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 10553 Comm: kworker/u8:16 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: writeback wb_workfn (flush-7:6)
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EXT4-fs (loop6): This should not happen!! Data will be lost