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BUG: KCSAN: data-race in data_alloc / data_push_tail

write to 0xffffffff86ed7578 of 8 bytes by task 20970 on cpu 0:
 data_alloc+0x216/0x2c0 kernel/printk/printk_ringbuffer.c:1074
 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
 ext4_setup_super+0x554/0x560 fs/ext4/super.c:3142
 __ext4_fill_super fs/ext4/super.c:5503 [inline]
 ext4_fill_super+0x3051/0x39a0 fs/ext4/super.c:5712
 get_tree_bdev+0x272/0x300 fs/super.c:1598
 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5744
 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 0xffffffff86ed7578 of 8 bytes by task 20961 on cpu 1:
 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
 init_rescuer+0x1b0/0x1c0 kernel/workqueue.c:4655
 alloc_workqueue+0x996/0xc30 kernel/workqueue.c:4724
 nci_register_device+0x320/0x570 net/nfc/nci/core.c:1246
 virtual_ncidev_open+0xdc/0x140 drivers/nfc/virtual_ncidev.c:153
 misc_open+0x203/0x240 drivers/char/misc.c:165
 chrdev_open+0x322/0x390 fs/char_dev.c:414
 do_dentry_open+0x635/0xbd0 fs/open.c:948
 vfs_open+0x4a/0x50 fs/open.c:1082
 do_open fs/namei.c:3622 [inline]
 path_openat+0x1819/0x1d70 fs/namei.c:3779
 do_filp_open+0xf6/0x200 fs/namei.c:3809
 do_sys_openat2+0xab/0x110 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1463
 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: 0x0000000100005470 -> 0x00000001000064f4

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 20961 Comm: syz-executor.2 Not tainted 6.7.0-rc7-syzkaller-00051-g2639772a11c8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
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