udevd[18891]: inotify_add_watch(7, /dev/loop4p4, 10) failed: No such file or directory
==================================================================
BUG: KCSAN: data-race in data_push_tail / string

write to 0xffffffff870a3320 of 1 bytes by task 18890 on cpu 0:
 string_nocheck lib/vsprintf.c:647 [inline]
 string+0x17b/0x220 lib/vsprintf.c:725
 vsnprintf+0xb57/0xe80 lib/vsprintf.c:2800
 vscnprintf+0x3e/0x80 lib/vsprintf.c:2906
 printk_sprint kernel/printk/printk.c:2089 [inline]
 vprintk_store+0x5f2/0xb50 kernel/printk/printk.c:2203
 vprintk_emit+0xcc/0x430 kernel/printk/printk.c:2249
 devkmsg_emit+0x82/0xa4 kernel/printk/printk.c:649
 devkmsg_write+0x244/0x290 kernel/printk/printk.c:712
 do_iter_write+0x494/0x750 fs/read_write.c:861
 vfs_writev fs/read_write.c:934 [inline]
 do_writev+0x256/0x4b0 fs/read_write.c:977
 __do_sys_writev fs/read_write.c:1050 [inline]
 __se_sys_writev fs/read_write.c:1047 [inline]
 __x64_sys_writev+0x41/0x50 fs/read_write.c:1047
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffffffff870a3320 of 8 bytes by task 18891 on cpu 1:
 data_make_reusable kernel/printk/printk_ringbuffer.c:590 [inline]
 data_push_tail+0x10f/0x440 kernel/printk/printk_ringbuffer.c:675
 data_alloc+0xbc/0x2b0 kernel/printk/printk_ringbuffer.c:1046
 prb_reserve+0x897/0xbd0 kernel/printk/printk_ringbuffer.c:1555
 vprintk_store+0x51c/0xb50 kernel/printk/printk.c:2193
 vprintk_emit+0xcc/0x430 kernel/printk/printk.c:2249
 devkmsg_emit+0x82/0xa4 kernel/printk/printk.c:649
 devkmsg_write+0x244/0x290 kernel/printk/printk.c:712
 do_iter_write+0x494/0x750 fs/read_write.c:861
 vfs_writev fs/read_write.c:934 [inline]
 do_writev+0x256/0x4b0 fs/read_write.c:977
 __do_sys_writev fs/read_write.c:1050 [inline]
 __se_sys_writev fs/read_write.c:1047 [inline]
 __x64_sys_writev+0x41/0x50 fs/read_write.c:1047
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000100013eb4 -> 0x2f7665642f202c37

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 18891 Comm: udevd Not tainted 6.1.0-rc1-syzkaller-00093-g6d36c728bc2e-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
==================================================================
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
Buffer I/O error on dev loop4p4, logical block 0, async page read
Buffer I/O error on dev loop4p4, logical block 0, async page read
udevd[18891]: inotify_add_watch(7, /dev/loop4p4, 10) failed: No such file or directory
udevd[18891]: inotify_add_watch(7, /dev/loop4p4, 10) failed: No such file or directory
udevd[18891]: inotify_add_watch(7, /dev/loop4p4, 10) failed: No such file or directory
blk_print_req_error: 18 callbacks suppressed
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev loop4p4, logical block 0, async page read
udevd[18891]: inotify_add_watch(7, /dev/loop4p4, 10) failed: No such file or directory
udevd[18891]: inotify_add_watch(7, /dev/loop4p4, 10) failed: No such file or directory
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev loop4p4, logical block 0, async page read
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
Buffer I/O error on dev loop4p4, logical block 0, async page read
Buffer I/O error on dev loop4p4, logical block 0, async page read
udevd[18891]: inotify_add_watch(7, /dev/loop4p4, 10) failed: No such file or directory
udevd[18891]: inotify_add_watch(7, /dev/loop4p4, 10) failed: No such file or directory
udevd[18891]: inotify_add_watch(7, /dev/loop4p4, 10) failed: No such file or directory