==================================================================
BUG: KCSAN: data-race in data_alloc / prb_reserve

write to 0xffffffff86671478 of 8 bytes by task 22725 on cpu 1:
 data_alloc+0x291/0x2c0 kernel/printk/printk_ringbuffer.c:1096
 prb_reserve+0x85e/0xb60 kernel/printk/printk_ringbuffer.c:1669
 vprintk_store+0x558/0x870 kernel/printk/printk.c:2326
 vprintk_emit+0x168/0x690 kernel/printk/printk.c:2408
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2447
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x7a/0xa0 kernel/printk/printk.c:2457
 __ext4_msg+0x18e/0x1a0 fs/ext4/super.c:998
 ext4_orphan_cleanup+0x39a/0x9e0 fs/ext4/orphan.c:437
 __ext4_fill_super fs/ext4/super.c:5602 [inline]
 ext4_fill_super+0x32ec/0x3630 fs/ext4/super.c:5722
 get_tree_bdev_flags+0x29f/0x310 fs/super.c:1636
 get_tree_bdev+0x1f/0x30 fs/super.c:1659
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5754
 vfs_get_tree+0x56/0x1e0 fs/super.c:1814
 do_new_mount+0x227/0x690 fs/namespace.c:3560
 path_mount+0x49b/0xb30 fs/namespace.c:3887
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:4088
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4088
 x64_sys_call+0x2c84/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:166
 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 0xffffffff86671478 of 8 bytes by task 22734 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:482 [inline]
 desc_push_tail kernel/printk/printk_ringbuffer.c:778 [inline]
 desc_reserve kernel/printk/printk_ringbuffer.c:924 [inline]
 prb_reserve+0x235/0xb60 kernel/printk/printk_ringbuffer.c:1619
 vprintk_store+0x558/0x870 kernel/printk/printk.c:2326
 vprintk_emit+0x168/0x690 kernel/printk/printk.c:2408
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2447
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x7a/0xa0 kernel/printk/printk.c:2457
 buffer_io_error fs/buffer.c:130 [inline]
 end_buffer_async_read+0x23d/0x260 fs/buffer.c:260
 end_buffer_async_read_io+0x1a/0x30 fs/buffer.c:370
 end_bio_bh_io_sync+0x76/0xa0 fs/buffer.c:2766
 bio_endio+0x369/0x410 block/bio.c:1548
 blk_mq_submit_bio+0x405/0xf40
 __submit_bio+0xf2/0x4f0 block/blk-core.c:628
 __submit_bio_noacct_mq block/blk-core.c:715 [inline]
 submit_bio_noacct_nocheck+0x295/0x6e0 block/blk-core.c:744
 submit_bio_noacct+0x6e1/0x930 block/blk-core.c:867
 submit_bio+0x218/0x230 block/blk-core.c:909
 submit_bh_wbc+0x2ed/0x330 fs/buffer.c:2814
 submit_bh fs/buffer.c:2819 [inline]
 block_read_full_folio+0x663/0x6f0 fs/buffer.c:2446
 blkdev_read_folio+0x1c/0x30 block/fops.c:467
 filemap_read_folio mm/filemap.c:2400 [inline]
 do_read_cache_folio+0x108/0x5b0 mm/filemap.c:3884
 read_cache_folio+0x3a/0x50 mm/filemap.c:3916
 read_mapping_folio include/linux/pagemap.h:1023 [inline]
 read_part_sector+0x6e/0x130 block/partitions/core.c:722
 read_lba+0xdf/0x1d0 block/partitions/efi.c:248
 find_valid_gpt block/partitions/efi.c:603 [inline]
 efi_partition+0x1ce/0x1360 block/partitions/efi.c:720
 check_partition block/partitions/core.c:141 [inline]
 blk_add_partitions block/partitions/core.c:589 [inline]
 bdev_disk_changed+0x481/0xcb0 block/partitions/core.c:693
 loop_reread_partitions+0x47/0xb0 drivers/block/loop.c:537
 loop_configure+0xa1c/0xa50 drivers/block/loop.c:1123
 lo_ioctl+0x613/0x14f0
 blkdev_ioctl+0x359/0x450 block/ioctl.c:693
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xc9/0x140 fs/ioctl.c:892
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:892
 x64_sys_call+0x1690/0x2dc0 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: 0x0000000000088360 -> 0x0000000000129228

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 22734 Comm: syz.9.6596 Tainted: G        W          6.14.0-rc7-syzkaller-00205-g586de92313fc #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================
Buffer I/O error on dev loop9, logical block 0, async page read
Buffer I/O error on dev loop9, logical block 0, async page read
 loop9: unable to read partition table
loop_reread_partitions: partition scan of loop9 (�被������ڬ��dƤ����ݡ�����

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