loop4: detected capacity change from 0 to 764
==================================================================
BUG: KCSAN: data-race in data_push_tail / vsnprintf

write to 0xffffffff88e2fe0b of 61 bytes by task 29025 on cpu 1:
 vsnprintf+0x2ce/0x890 lib/vsprintf.c:2878
 va_format lib/vsprintf.c:1728 [inline]
 pointer+0x833/0xcf0 lib/vsprintf.c:2548
 vsnprintf+0x491/0x890 lib/vsprintf.c:2930
 vscnprintf+0x41/0x90 lib/vsprintf.c:2991
 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2189
 vprintk_store+0x599/0x860 kernel/printk/printk.c:2309
 vprintk_emit+0x10d/0x580 kernel/printk/printk.c:2399
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2438
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2448
 __ext4_msg+0x135/0x1a0 fs/ext4/super.c:983
 ext4_check_quota_consistency fs/ext4/super.c:-1 [inline]
 ext4_check_opt_consistency+0xb05/0xb10 fs/ext4/super.c:2811
 __ext4_fill_super fs/ext4/super.c:5311 [inline]
 ext4_fill_super+0x192c/0x35d0 fs/ext4/super.c:5734
 get_tree_bdev_flags+0x28e/0x300 fs/super.c:1691
 get_tree_bdev+0x1f/0x30 fs/super.c:1714
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5766
 vfs_get_tree+0x57/0x1d0 fs/super.c:1751
 fc_mount fs/namespace.c:1208 [inline]
 do_new_mount_fc fs/namespace.c:3651 [inline]
 do_new_mount+0x24d/0x660 fs/namespace.c:3727
 path_mount+0x4a5/0xb70 fs/namespace.c:4037
 do_mount fs/namespace.c:4050 [inline]
 __do_sys_mount fs/namespace.c:4238 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4215
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4215
 x64_sys_call+0x2b51/0x3000 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 0xffffffff88e2fe18 of 8 bytes by task 29020 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:2299
 vprintk_emit+0x10d/0x580 kernel/printk/printk.c:2399
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2438
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2448
 isofs_read_inode fs/isofs/inode.c:1378 [inline]
 __isofs_iget+0xfe9/0x1100 fs/isofs/inode.c:1519
 isofs_iget fs/isofs/isofs.h:135 [inline]
 isofs_get_blocks+0x185/0x490 fs/isofs/inode.c:1064
 isofs_get_block fs/isofs/inode.c:1117 [inline]
 isofs_bmap fs/isofs/inode.c:1128 [inline]
 isofs_bread+0x5b/0x100 fs/isofs/inode.c:1136
 isofs_find_entry fs/isofs/namei.c:59 [inline]
 isofs_lookup+0x1a8/0x930 fs/isofs/namei.c:165
 __lookup_slow+0x190/0x250 fs/namei.c:1816
 lookup_slow+0x3c/0x60 fs/namei.c:1833
 walk_component fs/namei.c:2151 [inline]
 link_path_walk+0x753/0x900 fs/namei.c:2519
 path_lookupat+0x63/0x2a0 fs/namei.c:2675
 filename_lookup+0x147/0x340 fs/namei.c:2705
 user_path_at+0x3e/0x130 fs/namei.c:3215
 inotify_find_inode fs/notify/inotify/inotify_user.c:377 [inline]
 __do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:771 [inline]
 __se_sys_inotify_add_watch+0x102/0x7b0 fs/notify/inotify/inotify_user.c:729
 __x64_sys_inotify_add_watch+0x43/0x50 fs/notify/inotify/inotify_user.c:729
 x64_sys_call+0xfc7/0x3000 arch/x86/include/generated/asm/syscalls_64.h:255
 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

value changed: 0x0000000100001932 -> 0x736e6f6974706f20

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 29020 Comm: syz.4.8310 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
==================================================================
rock: directory entry would overflow storage
rock: sig=0x4f50, size=4, remaining=3
iso9660: Corrupted directory entry in block 6 of inode 1792