EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
==================================================================
BUG: KCSAN: data-race in _prb_read_valid / data_alloc

write to 0xffffffff86c73b48 of 8 bytes by task 54 on cpu 0:
 data_alloc+0x310/0x390 kernel/printk/printk_ringbuffer.c:1129
 prb_reserve+0x8d7/0xae0 kernel/printk/printk_ringbuffer.c:1724
 vprintk_store+0x54a/0x910 kernel/printk/printk.c:2354
 vprintk_emit+0x1a4/0x600 kernel/printk/printk.c:2455
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2504
 __ext4_error+0x225/0x310 fs/ext4/super.c:823
 ext4_release_dquot+0x2e6/0x460 fs/ext4/super.c:7037
 quota_release_workfn+0x260/0x540 fs/quota/dquot.c:843
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0x4de/0x9e0 kernel/workqueue.c:3358
 worker_thread+0x581/0x770 kernel/workqueue.c:3439
 kthread+0x22a/0x280 kernel/kthread.c:467
 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff86c73b48 of 16 bytes by task 15910 on cpu 1:
 desc_read kernel/printk/printk_ringbuffer.c:496 [inline]
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1931 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1979 [inline]
 _prb_read_valid+0x1bc/0x950 kernel/printk/printk_ringbuffer.c:2170
 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2242
 __console_flush_and_unlock kernel/printk/printk.c:3392 [inline]
 console_unlock+0x146/0x280 kernel/printk/printk.c:3413
 vprintk_emit+0x3e4/0x600 kernel/printk/printk.c:2479
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2504
 __ext4_msg+0x1aa/0x1c0 fs/ext4/super.c:995
 ext4_check_descriptors fs/ext4/super.c:3382 [inline]
 ext4_group_desc_init+0x133b/0x1570 fs/ext4/super.c:4914
 __ext4_fill_super fs/ext4/super.c:5410 [inline]
 ext4_fill_super+0x1f49/0x37c0 fs/ext4/super.c:5793
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1694
 get_tree_bdev+0x1f/0x30 fs/super.c:1717
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5825
 vfs_get_tree+0x57/0x1d0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3760 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3836
 path_mount+0x4d0/0xbc0 fs/namespace.c:4146
 do_mount fs/namespace.c:4159 [inline]
 __do_sys_mount fs/namespace.c:4348 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4325
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4325
 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 15910 Comm: syz.0.3262 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
==================================================================
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
set_capacity_and_notify: 7 callbacks suppressed
loop0: detected capacity change from 0 to 1024
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
loop0: detected capacity change from 0 to 1024
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
loop0: detected capacity change from 0 to 1024
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
loop0: detected capacity change from 0 to 1024
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
loop0: detected capacity change from 0 to 1024
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
loop0: detected capacity change from 0 to 1024
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
loop0: detected capacity change from 0 to 1024
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
loop0: detected capacity change from 0 to 1024
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
loop0: detected capacity change from 0 to 1024
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
loop0: detected capacity change from 0 to 1024
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
loop0: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
EXT4-fs error (device loop0): ext4_map_blocks:776: inode #3: block 17104912: comm syz.0.3262: lblock 2 mapped to illegal pblock 17104912 (length 1)
EXT4-fs (loop0): Remounting filesystem read-only
EXT4-fs (loop0): failed to initialize system zone (-117)
EXT4-fs (loop0): mount failed
EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (7780!=20869)
EXT4-fs (loop0): stripe (65535) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): invalid journal inode
EXT4-fs (loop0): can't get journal size
workqueue: Failed to create a rescuer kthread for wq "ext4-rsv-conversion": -EINTR
EXT4-fs: failed to create workqueue
EXT4-fs (loop0): mount failed