syzbot

loop5: detected capacity change from 0 to 512
EXT4-fs: Ignoring removed oldalloc option
==================================================================
BUG: KCSAN: data-race in data_alloc / prb_reserve

write to 0xffffffff8688bb40 of 8 bytes by task 7911 on cpu 0:
 data_alloc+0x290/0x2c0 kernel/printk/printk_ringbuffer.c:1096
 prb_reserve+0x86a/0xb80 kernel/printk/printk_ringbuffer.c:1669
 vprintk_store+0x552/0x860 kernel/printk/printk.c:2326
 vprintk_emit+0x174/0x6a0 kernel/printk/printk.c:2408
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2447
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x7f/0xb0 kernel/printk/printk.c:2457
 validate_nla lib/nlattr.c:414 [inline]
 __nla_validate_parse+0x131a/0x1f60 lib/nlattr.c:635
 __nla_parse+0x40/0x60 lib/nlattr.c:732
 __nlmsg_parse include/net/netlink.h:764 [inline]
 nlmsg_parse_deprecated include/net/netlink.h:805 [inline]
 rtnl_newlink+0xf4/0x1280 net/core/rtnetlink.c:3927
 rtnetlink_rcv_msg+0x65a/0x740 net/core/rtnetlink.c:6912
 netlink_rcv_skb+0x12f/0x230 net/netlink/af_netlink.c:2533
 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6939
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x605/0x6c0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0x609/0x720 net/netlink/af_netlink.c:1882
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg+0x140/0x180 net/socket.c:733
 ____sys_sendmsg+0x350/0x4e0 net/socket.c:2573
 ___sys_sendmsg net/socket.c:2627 [inline]
 __sys_sendmsg+0x1a0/0x240 net/socket.c:2659
 __do_sys_sendmsg net/socket.c:2664 [inline]
 __se_sys_sendmsg net/socket.c:2662 [inline]
 __x64_sys_sendmsg+0x46/0x50 net/socket.c:2662
 x64_sys_call+0x26f3/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff8688bb40 of 8 bytes by task 7915 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+0x239/0xb80 kernel/printk/printk_ringbuffer.c:1619
 vprintk_store+0x552/0x860 kernel/printk/printk.c:2326
 vprintk_emit+0x174/0x6a0 kernel/printk/printk.c:2408
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2447
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x7f/0xb0 kernel/printk/printk.c:2457
 __ext4_error+0x225/0x320 fs/ext4/super.c:830
 ext4_xattr_inode_iget+0x7a/0x210 fs/ext4/xattr.c:435
 ext4_xattr_inode_get+0x95/0x250 fs/ext4/xattr.c:535
 ext4_xattr_move_to_block fs/ext4/xattr.c:2643 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2745 [inline]
 ext4_expand_extra_isize_ea+0x8b7/0x1000 fs/ext4/xattr.c:2837
 __ext4_expand_extra_isize+0x256/0x290 fs/ext4/inode.c:5893
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5936 [inline]
 __ext4_mark_inode_dirty+0x2cd/0x440 fs/ext4/inode.c:6014
 ext4_evict_inode+0x82d/0xdf0 fs/ext4/inode.c:256
 evict+0x2de/0x550 fs/inode.c:810
 iput_final fs/inode.c:1898 [inline]
 iput+0x42a/0x5b0 fs/inode.c:1924
 ext4_process_orphan+0x1a9/0x1c0 fs/ext4/orphan.c:360
 ext4_orphan_cleanup+0x69c/0x9f0 fs/ext4/orphan.c:474
 __ext4_fill_super fs/ext4/super.c:5602 [inline]
 ext4_fill_super+0x32de/0x3620 fs/ext4/super.c:5722
 get_tree_bdev_flags+0x2b4/0x330 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:1759
 do_new_mount+0x246/0x6b0 fs/namespace.c:3878
 path_mount+0x49b/0xb30 fs/namespace.c:4205
 do_mount fs/namespace.c:4218 [inline]
 __do_sys_mount fs/namespace.c:4429 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4406
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4406
 x64_sys_call+0xd11/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x000000000019d4a8 -> 0x000000000024eaf0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 7915 Comm: syz.5.12613 Not tainted 6.14.0-syzkaller-01103-g2df0c02dab82 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================
EXT4-fs error (device loop5): ext4_xattr_inode_iget:436: comm syz.5.12613: Parent and EA inode have the same ino 15
EXT4-fs (loop5): Remounting filesystem read-only
EXT4-fs warning (device loop5): ext4_evict_inode:259: couldn't mark inode dirty (err -5)
EXT4-fs (loop5): 1 orphan inode deleted
EXT4-fs (loop5): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.
SELinux: (dev loop5, type ext4) getxattr errno 5
EXT4-fs (loop5): unmounting filesystem 00000000-0000-0000-0000-000000000000.
loop5: detected capacity change from 0 to 512
EXT4-fs (loop5): encrypted files will use data=ordered instead of data journaling mode
EXT4-fs (loop5): 1 truncate cleaned up
EXT4-fs (loop5): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.