kauditd_printk_skb: 429 callbacks suppressed
audit: type=1326 audit(1752501024.253:9455): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=15467 comm="syz.1.3547" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f434264e929 code=0x7ffc0000
==================================================================
BUG: KCSAN: data-race in data_push_tail / string

write to 0xffffffff88e42cf0 of 1 bytes by task 15474 on cpu 1:
 string_nocheck lib/vsprintf.c:643 [inline]
 string+0x187/0x220 lib/vsprintf.c:721
 vsnprintf+0x532/0x890 lib/vsprintf.c:2874
 va_format lib/vsprintf.c:1715 [inline]
 pointer+0x833/0xcf0 lib/vsprintf.c:2496
 vsnprintf+0x491/0x890 lib/vsprintf.c:2878
 vscnprintf+0x41/0x90 lib/vsprintf.c:2939
 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2216
 vprintk_store+0x599/0x860 kernel/printk/printk.c:2336
 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_inode+0x2ca/0x3f0 fs/ext4/super.c:844
 check_igot_inode+0x153/0x180 fs/ext4/inode.c:5105
 __ext4_iget+0x1eaa/0x21c0 fs/ext4/inode.c:5446
 ext4_xattr_inode_iget+0xa6/0x200 fs/ext4/xattr.c:437
 ext4_xattr_inode_get+0x92/0x240 fs/ext4/xattr.c:532
 ext4_xattr_move_to_block fs/ext4/xattr.c:2632 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2734 [inline]
 ext4_expand_extra_isize_ea+0x8b2/0x11f0 fs/ext4/xattr.c:2822
 __ext4_expand_extra_isize+0x246/0x280 fs/ext4/inode.c:6306
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6349 [inline]
 __ext4_mark_inode_dirty+0x29d/0x3f0 fs/ext4/inode.c:6427
 ext4_setattr+0xed0/0xfd0 fs/ext4/inode.c:5935
 notify_change+0x806/0x890 fs/attr.c:552
 do_truncate fs/open.c:68 [inline]
 do_ftruncate+0x34b/0x450 fs/open.c:195
 do_sys_ftruncate fs/open.c:210 [inline]
 __do_sys_ftruncate fs/open.c:215 [inline]
 __se_sys_ftruncate fs/open.c:213 [inline]
 __x64_sys_ftruncate+0x68/0xc0 fs/open.c:213
 x64_sys_call+0xd65/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:78
 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

read to 0xffffffff88e42cf0 of 8 bytes by task 29 on cpu 0:
 data_make_reusable kernel/printk/printk_ringbuffer.c:594 [inline]
 data_push_tail+0xfd/0x420 kernel/printk/printk_ringbuffer.c:679
 data_alloc+0xbf/0x2b0 kernel/printk/printk_ringbuffer.c:1054
 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
 kauditd_printk_skb kernel/audit.c:546 [inline]
 kauditd_hold_skb+0x1b1/0x1c0 kernel/audit.c:581
 kauditd_send_queue+0x273/0x2c0 kernel/audit.c:766
 kauditd_thread+0x421/0x630 kernel/audit.c:890
 kthread+0x489/0x510 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

value changed: 0x00000000fffffc9e -> 0x5f414520676e6973

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 29 Comm: kauditd Not tainted 6.16.0-rc6-syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================
audit: type=1326 audit(1752501024.563:9456): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=15467 comm="syz.1.3547" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f434264e929 code=0x7ffc0000