netlink: 144 bytes leftover after parsing attributes in process `syz.8.9022'.
loop8: detected capacity change from 0 to 4096
==================================================================
BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff866e3b90 of 8 bytes by task 9527 on cpu 1:
 prb_reserve+0x740/0xb60
 vprintk_store+0x53f/0x810 kernel/printk/printk.c:2301
 vprintk_emit+0x15e/0x680 kernel/printk/printk.c:2383
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2422
 vprintk+0x75/0x80 kernel/printk/printk_safe.c:68
 _printk+0x7a/0xa0 kernel/printk/printk.c:2432
 set_capacity_and_notify+0xff/0x160 block/genhd.c:86
 loop_set_size+0x2e/0x70 drivers/block/loop.c:232
 loop_configure+0x8a7/0xa30 drivers/block/loop.c:1102
 lo_ioctl+0x5f6/0x11c0
 blkdev_ioctl+0x359/0x450 block/ioctl.c:693
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xcd/0x140 fs/ioctl.c:893
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:893
 x64_sys_call+0x15cc/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff866e3b90 of 8 bytes by task 9525 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:486 [inline]
 prb_first_seq kernel/printk/printk_ringbuffer.c:1957 [inline]
 _prb_read_valid+0x3bb/0xba0 kernel/printk/printk_ringbuffer.c:2114
 prb_read_valid+0x3d/0x60 kernel/printk/printk_ringbuffer.c:2182
 printk_get_next_message+0xd8/0x6f0 kernel/printk/printk.c:2963
 console_emit_next_record kernel/printk/printk.c:3046 [inline]
 console_flush_all+0x28a/0x770 kernel/printk/printk.c:3180
 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline]
 console_unlock+0xab/0x330 kernel/printk/printk.c:3279
 vprintk_emit+0x3f4/0x680 kernel/printk/printk.c:2407
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2422
 vprintk+0x75/0x80 kernel/printk/printk_safe.c:68
 _printk+0x7a/0xa0 kernel/printk/printk.c:2432
 set_capacity_and_notify+0xff/0x160 block/genhd.c:86
 loop_set_size+0x2e/0x70 drivers/block/loop.c:232
 loop_configure+0x8a7/0xa30 drivers/block/loop.c:1102
 lo_ioctl+0x5f6/0x11c0
 blkdev_ioctl+0x359/0x450 block/ioctl.c:693
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xcd/0x140 fs/ioctl.c:893
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:893
 x64_sys_call+0x15cc/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000002e7a -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 9525 Comm: syz.8.9022 Tainted: G        W          6.12.0-rc6-syzkaller-00099-g7758b206117d #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================
EXT4-fs: Ignoring removed nomblk_io_submit option
EXT4-fs (loop8): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
batadv0: entered promiscuous mode
batadv_slave_0: entered promiscuous mode
batadv_slave_0: left promiscuous mode
batadv0: left promiscuous mode