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loop2: rw=0, sector=145, nr_sectors = 8 limit=128
syz.2.2965: attempt to access beyond end of device
loop2: rw=0, sector=145, nr_sectors = 8 limit=128
syz.2.2965: attempt to access beyond end of device
loop2: rw=0, sector=145, nr_sectors = 8 limit=128
==================================================================
BUG: KCSAN: data-race in data_alloc / prb_reserve

write to 0xffffffff8666b9a0 of 8 bytes by task 12404 on cpu 0:
 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+0x15e/0x680 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_grp_locked_error+0x53e/0x7b0 fs/ext4/super.c:1064
 ext4_mb_generate_buddy+0x247/0x2d0 fs/ext4/mballoc.c:1217
 ext4_mb_init_cache+0x848/0xbc0 fs/ext4/mballoc.c:1406
 ext4_mb_init_group+0x210/0x3b0 fs/ext4/mballoc.c:1543
 ext4_mb_load_buddy_gfp+0x6e0/0x750 fs/ext4/mballoc.c:1613
 ext4_mb_clear_bb fs/ext4/mballoc.c:6451 [inline]
 ext4_free_blocks+0x75c/0x14b0 fs/ext4/mballoc.c:6652
 ext4_clear_blocks+0x2a3/0x2c0 fs/ext4/indirect.c:888
 ext4_free_data fs/ext4/indirect.c:962 [inline]
 ext4_ind_truncate+0x5d5/0x880 fs/ext4/indirect.c:1154
 ext4_truncate+0x751/0xb10 fs/ext4/inode.c:4219
 ext4_process_orphan+0x113/0x1c0 fs/ext4/orphan.c:339
 ext4_orphan_cleanup+0x696/0x9e0 fs/ext4/orphan.c:474
 __ext4_fill_super fs/ext4/super.c:5602 [inline]
 ext4_fill_super+0x3306/0x3650 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 0xffffffff8666b9a0 of 8 bytes by task 12364 on cpu 1:
 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+0x15e/0x680 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
 bio_check_eod block/blk-core.c:557 [inline]
 submit_bio_noacct+0x82e/0x930 block/blk-core.c:790
 submit_bio+0x218/0x230 block/blk-core.c:910
 mpage_bio_submit_read fs/mpage.c:75 [inline]
 mpage_read_folio+0x98/0xd0 fs/mpage.c:394
 fat_read_folio+0x1c/0x30 fs/fat/inode.c:204
 filemap_read_folio+0x2a/0x110 mm/filemap.c:2358
 filemap_fault+0x613/0xb30 mm/filemap.c:3513
 __do_fault+0xb6/0x200 mm/memory.c:4908
 do_read_fault mm/memory.c:5323 [inline]
 do_fault mm/memory.c:5457 [inline]
 do_pte_missing mm/memory.c:3980 [inline]
 handle_pte_fault mm/memory.c:5820 [inline]
 __handle_mm_fault mm/memory.c:5963 [inline]
 handle_mm_fault+0xe98/0x2ac0 mm/memory.c:6131
 faultin_page mm/gup.c:1196 [inline]
 __get_user_pages+0xf2c/0x2670 mm/gup.c:1494
 populate_vma_page_range mm/gup.c:1932 [inline]
 __mm_populate+0x25b/0x3b0 mm/gup.c:2035
 do_mlock+0x4bd/0x570 mm/mlock.c:653
 __do_sys_mlock2 mm/mlock.c:674 [inline]
 __se_sys_mlock2 mm/mlock.c:664 [inline]
 __x64_sys_mlock2+0x72/0x90 mm/mlock.c:664
 x64_sys_call+0x971/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:326
 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: 0xfffffffffffcf6d8 -> 0x000000000007aec0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 12364 Comm: syz.2.2965 Not tainted 6.13.0-syzkaller-07078-gb46c89c08f41 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
==================================================================
syz.2.2965: attempt to access beyond end of device
loop2: rw=0, sector=145, nr_sectors = 8 limit=128