audit: type=1326 audit(383.077:42621): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=24935 comm="syz.4.8113" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fa79d11ec29 code=0x7ffc0000
audit: type=1326 audit(383.107:42622): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=24935 comm="syz.4.8113" exe="/root/syz-executor" sig=0 arch=c000003e syscall=240 compat=0 ip=0x7fa79d11ec29 code=0x7ffc0000
==================================================================
BUG: KCSAN: data-race in data_push_tail / vsnprintf

write to 0xffffffff88e45e9c of 9 bytes by task 24916 on cpu 0:
 vsnprintf+0x2ce/0x890 lib/vsprintf.c:2878
 vscnprintf+0x41/0x90 lib/vsprintf.c:2991
 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
 __ext4_mark_inode_dirty+0xbd/0x3f0 fs/ext4/inode.c:6512
 ext4_evict_inode+0xade/0xd90 fs/ext4/inode.c:302
 evict+0x2e3/0x550 fs/inode.c:810
 iput_final fs/inode.c:1897 [inline]
 iput+0x447/0x5b0 fs/inode.c:1923
 ext4_process_orphan+0x1a9/0x1c0 fs/ext4/orphan.c:360
 ext4_orphan_cleanup+0x6a8/0xa00 fs/ext4/orphan.c:474
 __ext4_fill_super fs/ext4/super.c:5609 [inline]
 ext4_fill_super+0x3260/0x35d0 fs/ext4/super.c:5728
 get_tree_bdev_flags+0x28e/0x300 fs/super.c:1692
 get_tree_bdev+0x1f/0x30 fs/super.c:1715
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5760
 vfs_get_tree+0x57/0x1d0 fs/super.c:1815
 do_new_mount+0x207/0x5e0 fs/namespace.c:3808
 path_mount+0x4a4/0xb20 fs/namespace.c:4123
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4324
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4324
 x64_sys_call+0x2b4d/0x2ff0 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

read to 0xffffffff88e45ea0 of 8 bytes by task 29 on cpu 1:
 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+0x270/0x2c0 kernel/audit.c:766
 kauditd_thread+0x421/0x630 kernel/audit.c:890
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x11f/0x1b0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x000000010000119c -> 0x63203a3531232065

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 29 Comm: kauditd Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
==================================================================
audit: type=1326 audit(383.107:42623): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=24935 comm="syz.4.8113" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fa79d11ec29 code=0x7ffc0000
audit: type=1326 audit(383.107:42624): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=24935 comm="syz.4.8113" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fa79d11ec29 code=0x7ffc0000
audit: type=1326 audit(383.107:42625): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=24935 comm="syz.4.8113" exe="/root/syz-executor" sig=0 arch=c000003e syscall=242 compat=0 ip=0x7fa79d11ec29 code=0x7ffc0000
audit: type=1326 audit(383.107:42626): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=24935 comm="syz.4.8113" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fa79d11ec29 code=0x7ffc0000
audit: type=1326 audit(383.107:42627): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=24935 comm="syz.4.8113" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fa79d11ec29 code=0x7ffc0000