syzbot

__nla_validate_parse: 7 callbacks suppressed
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'.
==================================================================
BUG: KCSAN: data-race in data_alloc / data_push_tail

write to 0xffffffff86eb6458 of 8 bytes by task 2840 on cpu 1:
 data_alloc+0x205/0x2b0 kernel/printk/printk_ringbuffer.c:1074
 prb_reserve+0x897/0xbd0 kernel/printk/printk_ringbuffer.c:1555
 vprintk_store+0x50b/0xad0 kernel/printk/printk.c:2282
 vprintk_emit+0xcc/0x430 kernel/printk/printk.c:2338
 vprintk_default+0x22/0x30 kernel/printk/printk.c:2368
 vprintk+0x7f/0x90 kernel/printk/printk_safe.c:50
 _printk+0x76/0xa0 kernel/printk/printk.c:2378
 pr_cont_kernfs_path+0x8f/0xb0 fs/kernfs/dir.c:280
 pr_cont_cgroup_path include/linux/cgroup.h:612 [inline]
 pids_can_fork+0x22e/0x250 kernel/cgroup/pids.c:254
 cgroup_can_fork+0x572/0x950 kernel/cgroup/cgroup.c:6520
 copy_process+0x11e7/0x2090 kernel/fork.c:2370
 create_io_thread+0x6d/0xa0 kernel/fork.c:2629
 create_io_worker+0x119/0x310 io_uring/io-wq.c:820
 io_wqe_create_worker io_uring/io-wq.c:310 [inline]
 io_wqe_enqueue+0x405/0x500 io_uring/io-wq.c:936
 io_wq_enqueue+0x31/0x40 io_uring/io-wq.c:960
 io_queue_iowq+0x1d2/0x2f0 io_uring/io_uring.c:475
 io_queue_sqe_fallback+0x82/0xe0 io_uring/io_uring.c:2059
 io_submit_sqe+0x8bc/0xa50 io_uring/io_uring.c:2281
 io_submit_sqes+0x274/0x550 io_uring/io_uring.c:2397
 __do_sys_io_uring_enter io_uring/io_uring.c:3345 [inline]
 __se_sys_io_uring_enter+0x1ef/0xc40 io_uring/io_uring.c:3277
 __x64_sys_io_uring_enter+0x74/0x80 io_uring/io_uring.c:3277
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffffffff86eb6458 of 8 bytes by task 2835 on cpu 0:
 data_make_reusable kernel/printk/printk_ringbuffer.c:590 [inline]
 data_push_tail+0x10f/0x440 kernel/printk/printk_ringbuffer.c:675
 data_alloc+0xbc/0x2b0 kernel/printk/printk_ringbuffer.c:1046
 prb_reserve+0x897/0xbd0 kernel/printk/printk_ringbuffer.c:1555
 vprintk_store+0x50b/0xad0 kernel/printk/printk.c:2282
 vprintk_emit+0xcc/0x430 kernel/printk/printk.c:2338
 vprintk_default+0x22/0x30 kernel/printk/printk.c:2368
 vprintk+0x7f/0x90 kernel/printk/printk_safe.c:50
 _printk+0x76/0xa0 kernel/printk/printk.c:2378
 __nla_validate_parse+0x155a/0x1970 lib/nlattr.c:612
 __nla_parse+0x3c/0x50 lib/nlattr.c:697
 nla_parse_nested_deprecated include/net/netlink.h:1280 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3506 [inline]
 rtnl_newlink+0x438/0x16f0 net/core/rtnetlink.c:3637
 rtnetlink_rcv_msg+0x811/0x8d0 net/core/rtnetlink.c:6141
 netlink_rcv_skb+0x13e/0x250 net/netlink/af_netlink.c:2564
 rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:6159
 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
 netlink_unicast+0x58a/0x660 net/netlink/af_netlink.c:1356
 netlink_sendmsg+0x666/0x760 net/netlink/af_netlink.c:1932
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 ____sys_sendmsg+0x38f/0x500 net/socket.c:2476
 ___sys_sendmsg net/socket.c:2530 [inline]
 __sys_sendmsg+0x19a/0x230 net/socket.c:2559
 __do_sys_sendmsg net/socket.c:2568 [inline]
 __se_sys_sendmsg net/socket.c:2566 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2566
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00000000ffffe280 -> 0x00000000ffffed89

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2835 Comm: syz-executor.2 Not tainted 6.2.0-rc3-syzkaller-00008-g1fe4fd6f5cad-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
==================================================================
netlink: 'syz-executor.2': attribute type 5 has an invalid length.
syz-executor.2 (2835) used greatest stack depth: 9248 bytes left