EXT4-fs error (device loop9): ext4_do_update_inode:5801: inode #15: comm syz.9.5459: corrupted inode contents
EXT4-fs error (device loop9): __ext4_ext_dirty:207: inode #15: comm syz.9.5459: mark_inode_dirty error
EXT4-fs error (device loop9): ext4_do_update_inode:5801: inode #15: comm syz.9.5459: corrupted inode contents
==================================================================
BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff86eaa8c0 of 88 bytes by task 29 on cpu 1:
 prb_reserve+0x6fb/0xaf0 kernel/printk/printk_ringbuffer.c:1693
 vprintk_store+0x54e/0x910 kernel/printk/printk.c:2354
 vprintk_emit+0x1a4/0x610 kernel/printk/printk.c:2455
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2504
 kauditd_printk_skb kernel/audit.c:588 [inline]
 kauditd_hold_skb+0x1b1/0x1c0 kernel/audit.c:623
 kauditd_send_queue+0x275/0x2d0 kernel/audit.c:808
 kauditd_thread+0x439/0x660 kernel/audit.c:932
 kthread+0x223/0x270 kernel/kthread.c:436
 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff86eaa8c0 of 8 bytes by task 24831 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:500 [inline]
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1934 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1982 [inline]
 _prb_read_valid+0x18c/0x930 kernel/printk/printk_ringbuffer.c:2173
 desc_update_last_finalized+0x8f/0x170 kernel/printk/printk_ringbuffer.c:1573
 prb_final_commit+0x111/0x150 kernel/printk/printk_ringbuffer.c:1842
 vprintk_store+0x88f/0x910 kernel/printk/printk.c:2381
 vprintk_emit+0x1a4/0x610 kernel/printk/printk.c:2455
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2504
 __ext4_error_inode+0x298/0x3a0 fs/ext4/super.c:861
 ext4_do_update_inode fs/ext4/inode.c:5801 [inline]
 ext4_mark_iloc_dirty+0x347/0xe40 fs/ext4/inode.c:6473
 __ext4_mark_inode_dirty+0x31d/0x410 fs/ext4/inode.c:6707
 __ext4_ext_dirty+0xda/0x1f0 fs/ext4/extents.c:207
 ext4_ext_remove_space+0x26dd/0x28b0 fs/ext4/extents.c:3088
 ext4_ext_truncate+0xc7/0x160 fs/ext4/extents.c:4574
 ext4_truncate+0x7c9/0xa50 fs/ext4/inode.c:4698
 ext4_setattr+0xbfc/0x1170 fs/ext4/inode.c:6220
 notify_change+0x842/0x8c0 fs/attr.c:556
 do_truncate+0x14f/0x190 fs/open.c:68
 handle_truncate fs/namei.c:4300 [inline]
 do_open fs/namei.c:4841 [inline]
 path_openat+0xd21/0x10d0 fs/namei.c:5000
 do_file_open+0x16c/0x290 fs/namei.c:5029
 do_sys_openat2+0xa0/0x130 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_creat fs/open.c:1501 [inline]
 __se_sys_creat fs/open.c:1495 [inline]
 __x64_sys_creat+0x65/0x90 fs/open.c:1495
 x64_sys_call+0xea6/0x2550 arch/x86/include/generated/asm/syscalls_64.h:86
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000002408 -> 0x0000000000004408

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 24831 Comm: syz.9.5459 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
==================================================================
EXT4-fs error (device loop9): __ext4_ext_dirty:207: inode #15: comm syz.9.5459: mark_inode_dirty error
EXT4-fs error (device loop9): ext4_do_update_inode:5801: inode #15: comm syz.9.5459: corrupted inode contents
EXT4-fs error (device loop9): ext4_truncate:4721: inode #15: comm syz.9.5459: mark_inode_dirty error
EXT4-fs error (device loop9) in ext4_setattr:6247: Corrupt filesystem
EXT4-fs error (device loop9): ext4_do_update_inode:5801: inode #15: comm syz.9.5459: corrupted inode contents