EXT4-fs error (device loop5): ext4_validate_block_bitmap:441: comm syz.5.21441: bg 0: block 248: padding at end of block bitmap is not set
EXT4-fs error (device loop5): ext4_acquire_dquot:6937: comm syz.5.21441: Failed to acquire dquot type 1
==================================================================
BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff868e5030 of 88 bytes by task 19484 on cpu 1:
 prb_reserve+0x696/0xaf0 kernel/printk/printk_ringbuffer.c:1635
 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2326
 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2475
 ib_get_eth_speed+0x33d/0x4b0 drivers/infiniband/core/verbs.c:2006
 rxe_query_port+0x7d/0x220 drivers/infiniband/sw/rxe/rxe_verbs.c:62
 __ib_query_port drivers/infiniband/core/device.c:2148 [inline]
 ib_query_port+0x125/0x3d0 drivers/infiniband/core/device.c:2180
 ib_setup_port_attrs+0x14a/0x1430 drivers/infiniband/core/sysfs.c:1429
 add_one_compat_dev+0x261/0x360 drivers/infiniband/core/device.c:1005
 rdma_dev_init_net+0x182/0x210 drivers/infiniband/core/device.c:1221
 ops_init+0x227/0x2e0 net/core/net_namespace.c:136
 setup_net+0x82/0x200 net/core/net_namespace.c:438
 copy_net_ns+0x266/0x390 net/core/net_namespace.c:570
 create_new_namespaces+0x20e/0x3d0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xe8/0x120 kernel/nsproxy.c:218
 ksys_unshare+0x3d0/0x6d0 kernel/fork.c:3127
 __do_sys_unshare kernel/fork.c:3198 [inline]
 __se_sys_unshare kernel/fork.c:3196 [inline]
 __x64_sys_unshare+0x1f/0x30 kernel/fork.c:3196
 x64_sys_call+0x2911/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:273
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff868e5030 of 8 bytes by task 19477 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:486 [inline]
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1874 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1922 [inline]
 _prb_read_valid+0x1c4/0x920 kernel/printk/printk_ringbuffer.c:2113
 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2185
 __console_flush_and_unlock kernel/printk/printk.c:3304 [inline]
 console_unlock+0x164/0x330 kernel/printk/printk.c:3325
 vprintk_emit+0x388/0x650 kernel/printk/printk.c:2450
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2475
 __ext4_error+0x248/0x320 fs/ext4/super.c:813
 ext4_acquire_dquot+0x1bb/0x200 fs/ext4/super.c:6935
 dqget+0x535/0x8d0 fs/quota/dquot.c:977
 __dquot_initialize+0x20c/0x7c0 fs/quota/dquot.c:1505
 dquot_initialize+0x1a/0x30 fs/quota/dquot.c:1567
 ext4_process_orphan+0x32/0x1c0 fs/ext4/orphan.c:329
 ext4_orphan_cleanup+0x6a8/0xa00 fs/ext4/orphan.c:474
 __ext4_fill_super fs/ext4/super.c:5609 [inline]
 ext4_fill_super+0x3260/0x35d0 fs/ext4/super.c:5728
 get_tree_bdev_flags+0x28e/0x300 fs/super.c:1692
 get_tree_bdev+0x1f/0x30 fs/super.c:1715
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5760
 vfs_get_tree+0x57/0x1d0 fs/super.c:1815
 do_new_mount+0x207/0x5e0 fs/namespace.c:3808
 path_mount+0x4a4/0xb20 fs/namespace.c:4123
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4324
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4324
 x64_sys_call+0x2b4d/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000006e08 -> 0x0000000000008e08

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 19477 Comm: syz.5.21441 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
==================================================================
EXT4-fs (loop5): 1 truncate cleaned up
EXT4-fs (loop5): mounted filesystem 00000000-0000-0000-0008-000000000000 r/w without journal. Quota mode: writeback.