audit: type=1326 audit(1768440927.220:23291): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=10590 comm="syz.3.2362" exe="/root/syz-executor" sig=0 arch=c000003e syscall=230 compat=0 ip=0x7f6dfb442005 code=0x7ffc0000
audit: type=1326 audit(1768440927.230:23292): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=10590 comm="syz.3.2362" exe="/root/syz-executor" sig=0 arch=c000003e syscall=230 compat=0 ip=0x7f6dfb442005 code=0x7ffc0000
==================================================================
BUG: KCSAN: data-race in data_push_tail / vsnprintf

write to 0xffffffff88ea08a8 of 24 bytes by task 7354 on cpu 1:
 vsnprintf+0x2ce/0x860 lib/vsprintf.c:2898
 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
 __ext4_error_inode+0x30f/0x3f0 fs/ext4/super.c:848
 __check_block_validity fs/ext4/inode.c:389 [inline]
 ext4_map_blocks+0xa66/0xd20 fs/ext4/inode.c:-1
 ext4_getblk+0x114/0x510 fs/ext4/inode.c:984
 ext4_bread+0x28/0x110 fs/ext4/inode.c:1047
 ext4_quota_read+0xe8/0x260 fs/ext4/super.c:7304
 read_blk fs/quota/quota_tree.c:61 [inline]
 remove_tree+0x129/0x1120 fs/quota/quota_tree.c:555
 qtree_delete_dquot fs/quota/quota_tree.c:617 [inline]
 qtree_release_dquot+0x16e/0x180 fs/quota/quota_tree.c:787
 v2_release_dquot+0x98/0xd0 fs/quota/quota_v2.c:391
 dquot_release+0x10e/0x210 fs/quota/dquot.c:540
 ext4_release_dquot+0x1e4/0x460 fs/ext4/super.c:-1
 quota_release_workfn+0x256/0x530 fs/quota/dquot.c:843
 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

read to 0xffffffff88ea08b0 of 8 bytes by task 29 on cpu 0:
 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
 kauditd_printk_skb kernel/audit.c:583 [inline]
 kauditd_hold_skb+0x1b1/0x1c0 kernel/audit.c:618
 kauditd_send_queue+0x273/0x2c0 kernel/audit.c:803
 kauditd_thread+0x442/0x680 kernel/audit.c:927
 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: 0x00000000fffff85d -> 0x642820726f727265

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 29 Comm: kauditd Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
==================================================================
audit: type=1326 audit(1768440927.230:23293): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=10590 comm="syz.3.2362" exe="/root/syz-executor" sig=0 arch=c000003e syscall=230 compat=0 ip=0x7f6dfb442005 code=0x7ffc0000
audit: type=1326 audit(1768440927.230:23294): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=10590 comm="syz.3.2362" exe="/root/syz-executor" sig=0 arch=c000003e syscall=230 compat=0 ip=0x7f6dfb442005 code=0x7ffc0000
audit: type=1326 audit(1768440927.230:23295): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=10590 comm="syz.3.2362" exe="/root/syz-executor" sig=0 arch=c000003e syscall=230 compat=0 ip=0x7f6dfb442005 code=0x7ffc0000
audit: type=1326 audit(1768440927.230:23296): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=10590 comm="syz.3.2362" exe="/root/syz-executor" sig=0 arch=c000003e syscall=230 compat=0 ip=0x7f6dfb442005 code=0x7ffc0000
audit: type=1326 audit(1768440927.230:23297): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=10590 comm="syz.3.2362" exe="/root/syz-executor" sig=0 arch=c000003e syscall=230 compat=0 ip=0x7f6dfb442005 code=0x7ffc0000