loop5: detected capacity change from 0 to 1764
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BUG: KCSAN: data-race in data_push_tail / vsnprintf

write to 0xffffffff86eca114 of 1 bytes by task 2731 on cpu 1:
 vsnprintf+0xdd0/0xe20
 vscnprintf+0x42/0x80 lib/vsprintf.c:2925
 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2124
 vprintk_store+0x56f/0x800 kernel/printk/printk.c:2238
 vprintk_emit+0xd0/0x5d0 kernel/printk/printk.c:2284
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2318
 vprintk+0x71/0x80 kernel/printk/printk_safe.c:45
 _printk+0x7a/0xa0 kernel/printk/printk.c:2328
 isofs_fill_super+0x1765/0x1840 fs/isofs/inode.c:940
 mount_bdev+0x185/0x1f0 fs/super.c:1650
 isofs_mount+0x31/0x40 fs/isofs/inode.c:1559
 legacy_get_tree+0x74/0xd0 fs/fs_context.c:662
 vfs_get_tree+0x51/0x1b0 fs/super.c:1771
 do_new_mount+0x203/0x660 fs/namespace.c:3337
 path_mount+0x496/0xb30 fs/namespace.c:3664
 do_mount fs/namespace.c:3677 [inline]
 __do_sys_mount fs/namespace.c:3886 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:3863
 __x64_sys_mount+0x67/0x80 fs/namespace.c:3863
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffffffff86eca110 of 8 bytes by task 2730 on cpu 0:
 data_make_reusable kernel/printk/printk_ringbuffer.c:590 [inline]
 data_push_tail+0x102/0x430 kernel/printk/printk_ringbuffer.c:675
 data_alloc+0xbe/0x2c0 kernel/printk/printk_ringbuffer.c:1046
 prb_reserve+0x893/0xbc0 kernel/printk/printk_ringbuffer.c:1555
 vprintk_store+0x53e/0x800 kernel/printk/printk.c:2228
 vprintk_emit+0xd0/0x5d0 kernel/printk/printk.c:2284
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2318
 vprintk+0x71/0x80 kernel/printk/printk_safe.c:45
 _printk+0x7a/0xa0 kernel/printk/printk.c:2328
 isofs_fill_super+0x1765/0x1840 fs/isofs/inode.c:940
 mount_bdev+0x185/0x1f0 fs/super.c:1650
 isofs_mount+0x31/0x40 fs/isofs/inode.c:1559
 legacy_get_tree+0x74/0xd0 fs/fs_context.c:662
 vfs_get_tree+0x51/0x1b0 fs/super.c:1771
 do_new_mount+0x203/0x660 fs/namespace.c:3337
 path_mount+0x496/0xb30 fs/namespace.c:3664
 do_mount fs/namespace.c:3677 [inline]
 __do_sys_mount fs/namespace.c:3886 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:3863
 __x64_sys_mount+0x67/0x80 fs/namespace.c:3863
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x000000010000648b -> 0x000000000a746f74

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2730 Comm: syz-executor.5 Not tainted 6.7.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
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