netlink: 36 bytes leftover after parsing attributes in process `syz.1.10860'. ================================================================== BUG: KCSAN: data-race in _prb_read_valid / data_alloc write to 0xffffffff868845a0 of 8 bytes by task 29 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 kauditd_printk_skb kernel/audit.c:546 [inline] kauditd_hold_skb+0x1b1/0x1c0 kernel/audit.c:581 kauditd_send_queue+0x270/0x2c0 kernel/audit.c:766 kauditd_thread+0x421/0x630 kernel/audit.c:890 kthread+0x486/0x510 kernel/kthread.c:464 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read to 0xffffffff868845a0 of 16 bytes by task 8518 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 __nla_validate_parse+0x1738/0x1d00 lib/nlattr.c:647 __nla_parse+0x40/0x60 lib/nlattr.c:732 __nlmsg_parse include/net/netlink.h:765 [inline] nlmsg_parse_deprecated include/net/netlink.h:806 [inline] rtnl_newlink+0xf1/0x12d0 net/core/rtnetlink.c:3970 rtnetlink_rcv_msg+0x5fb/0x6d0 net/core/rtnetlink.c:6955 netlink_rcv_skb+0x120/0x220 net/netlink/af_netlink.c:2534 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6982 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x59e/0x670 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x58b/0x6b0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x142/0x180 net/socket.c:727 ____sys_sendmsg+0x31e/0x4e0 net/socket.c:2566 ___sys_sendmsg+0x17b/0x1d0 net/socket.c:2620 __sys_sendmsg net/socket.c:2652 [inline] __do_sys_sendmsg net/socket.c:2657 [inline] __se_sys_sendmsg net/socket.c:2655 [inline] __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2655 x64_sys_call+0x2999/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd0/0x1a0 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: 8518 Comm: syz.1.10860 Not tainted 6.15.0-rc4-syzkaller-00147-gebd297a2affa #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 ==================================================================