EXT4-fs (loop2): mounted filesystem 00000000-0000-0000-0000-000000000000 ro without journal. Quota mode: writeback.
EXT4-fs error (device loop2): ext4_xattr_block_get:593: inode #16: comm syz.2.4282: corrupted xattr block 31: invalid header
==================================================================
BUG: KCSAN: data-race in _prb_read_valid / data_alloc

write to 0xffffffff86874f30 of 8 bytes by task 15916 on cpu 1:
 data_alloc+0x271/0x2b0 kernel/printk/printk_ringbuffer.c:1095
 prb_reserve+0x808/0xaf0 kernel/printk/printk_ringbuffer.c:1669
 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
 __ext4_warning_inode+0x17b/0x190 fs/ext4/super.c:1023
 __warn_no_space_for_csum fs/ext4/namei.c:362 [inline]
 ext4_dirblock_csum_verify fs/ext4/namei.c:375 [inline]
 __ext4_find_entry+0xde3/0xf40 fs/ext4/namei.c:1623
 ext4_lookup_entry fs/ext4/namei.c:1703 [inline]
 ext4_lookup+0xbb/0x390 fs/ext4/namei.c:1771
 lookup_one_qstr_excl+0xc8/0x250 fs/namei.c:1697
 filename_create+0x149/0x230 fs/namei.c:4140
 user_path_create+0x39/0x130 fs/namei.c:4187
 bpf_obj_do_pin kernel/bpf/inode.c:445 [inline]
 bpf_obj_pin_user+0xe0/0x230 kernel/bpf/inode.c:488
 bpf_obj_pin+0xac/0xd0 kernel/bpf/syscall.c:3048
 __sys_bpf+0x6cb/0x7b0 kernel/bpf/syscall.c:6032
 __do_sys_bpf kernel/bpf/syscall.c:6139 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6137 [inline]
 __x64_sys_bpf+0x41/0x50 kernel/bpf/syscall.c:6137
 x64_sys_call+0x2aea/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:322
 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 0xffffffff86874f30 of 16 bytes by task 15909 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:482 [inline]
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1874 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1922 [inline]
 _prb_read_valid+0x1bc/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_inode+0x2ca/0x3f0 fs/ext4/super.c:844
 check_xattrs+0x25e/0x7d0 fs/ext4/xattr.c:289
 __ext4_xattr_check_block fs/ext4/xattr.c:303 [inline]
 ext4_xattr_block_get fs/ext4/xattr.c:593 [inline]
 ext4_xattr_get+0x1ed/0x470 fs/ext4/xattr.c:708
 ext4_xattr_security_get+0x32/0x40 fs/ext4/xattr_security.c:20
 __vfs_getxattr+0x2aa/0x2c0 fs/xattr.c:423
 inode_doinit_use_xattr+0x7a/0x2d0 security/selinux/hooks.c:1371
 inode_doinit_with_dentry+0x596/0x7a0 security/selinux/hooks.c:1496
 selinux_d_instantiate+0x27/0x40 security/selinux/hooks.c:6519
 security_d_instantiate+0x7a/0xa0 security/security.c:4109
 d_splice_alias_ops+0x53/0x280 fs/dcache.c:2998
 d_splice_alias+0x1f/0x30 fs/dcache.c:3063
 ext4_lookup+0x194/0x390 fs/ext4/namei.c:1814
 __lookup_slow+0x193/0x250 fs/namei.c:1808
 lookup_slow+0x3c/0x60 fs/namei.c:1825
 walk_component+0x1ec/0x220 fs/namei.c:2129
 lookup_last fs/namei.c:2630 [inline]
 path_lookupat+0xfe/0x2a0 fs/namei.c:2654
 filename_lookup+0x147/0x340 fs/namei.c:2683
 vfs_statx+0x9d/0x390 fs/stat.c:353
 vfs_fstatat fs/stat.c:375 [inline]
 vfs_stat include/linux/fs.h:3588 [inline]
 __do_sys_newstat fs/stat.c:515 [inline]
 __se_sys_newstat+0x69/0x280 fs/stat.c:509
 __x64_sys_newstat+0x31/0x40 fs/stat.c:509
 x64_sys_call+0x73e/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:5
 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

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 15909 Comm: syz.2.4282 Tainted: G        W           6.16.0-syzkaller-12256-g561c80369df0 #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
==================================================================
SELinux: inode_doinit_use_xattr:  getxattr returned 117 for dev=loop2 ino=16
EXT4-fs error (device loop2): ext4_xattr_block_get:593: inode #16: comm syz.2.4282: corrupted xattr block 31: invalid header
SELinux: inode_doinit_use_xattr:  getxattr returned 117 for dev=loop2 ino=16
EXT4-fs error (device loop2): ext4_get_link:106: inode #16: comm syz.2.4282: bad symlink.