audit: type=1400 audit(1750636277.405:81043): avc:  denied  { mounton } for  pid=29662 comm="syz.0.8919" path="/103/file0" dev="tmpfs" ino=567 scontext=root:sysadm_r:sysadm_t tcontext=root:object_r:user_tmpfs_t tclass=dir permissive=1
audit: type=1400 audit(1750636277.435:81044): avc:  denied  { read write } for  pid=21527 comm="syz-executor" name="loop4" dev="devtmpfs" ino=104 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:fixed_disk_device_t tclass=blk_file permissive=1
==================================================================
BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff868d7a38 of 88 bytes by task 29657 on cpu 0:
 prb_reserve+0x696/0xaf0 kernel/printk/printk_ringbuffer.c:1635
 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
 debug_print_tree+0x17/0x110 fs/ext4/block_validity.c:132
 ext4_setup_system_zone+0x45b/0x610 fs/ext4/block_validity.c:265
 __ext4_fill_super fs/ext4/super.c:5531 [inline]
 ext4_fill_super+0x2e0b/0x34e0 fs/ext4/super.c:5724
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1681
 get_tree_bdev+0x1f/0x30 fs/super.c:1704
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5756
 vfs_get_tree+0x54/0x1d0 fs/super.c:1804
 do_new_mount+0x207/0x680 fs/namespace.c:3885
 path_mount+0x4a4/0xb20 fs/namespace.c:4209
 do_mount fs/namespace.c:4222 [inline]
 __do_sys_mount fs/namespace.c:4433 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4410
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4410
 x64_sys_call+0xd36/0x2fb0 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 0xffffffff868d7a38 of 8 bytes by task 29 on cpu 1:
 desc_read kernel/printk/printk_ringbuffer.c:486 [inline]
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1874 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1922 [inline]
 _prb_read_valid+0x1c4/0x920 kernel/printk/printk_ringbuffer.c:2113
 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2185
 __console_flush_and_unlock kernel/printk/printk.c:3304 [inline]
 console_unlock+0x164/0x330 kernel/printk/printk.c:3325
 vprintk_emit+0x388/0x650 kernel/printk/printk.c:2450
 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+0x486/0x510 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: 0x0000000000002b59 -> 0x0000000000004b59

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 29 Comm: kauditd Not tainted 6.16.0-rc2-syzkaller-00378-gb67ec639010f #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================
audit: type=1400 audit(1750636277.435:81045): avc:  denied  { open } for  pid=21527 comm="syz-executor" path="/dev/loop4" dev="devtmpfs" ino=104 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:fixed_disk_device_t tclass=blk_file permissive=1
audit: type=1400 audit(1750636277.435:81046): avc:  denied  { ioctl } for  pid=21527 comm="syz-executor" path="/dev/loop4" dev="devtmpfs" ino=104 ioctlcmd=0x4c01 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:fixed_disk_device_t tclass=blk_file permissive=1
audit: type=1400 audit(1750636277.495:81047): avc:  denied  { read write } for  pid=29662 comm="syz.0.8919" name="loop0" dev="devtmpfs" ino=905 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:device_t tclass=blk_file permissive=1
audit: type=1400 audit(1750636277.495:81048): avc:  denied  { open } for  pid=29662 comm="syz.0.8919" path="/dev/loop0" dev="devtmpfs" ino=905 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:device_t tclass=blk_file permissive=1
audit: type=1400 audit(1750636277.495:81049): avc:  denied  { ioctl } for  pid=29662 comm="syz.0.8919" path="/dev/loop0" dev="devtmpfs" ino=905 ioctlcmd=0x4c01 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:device_t tclass=blk_file permissive=1