audit: type=1326 audit(5796151601.958:47391): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=12914 comm="syz.2.12316" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f29d96debe9 code=0x7ffc0000 audit: type=1326 audit(5796151601.958:47392): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=12914 comm="syz.2.12316" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f29d96debe9 code=0x7ffc0000 ================================================================== BUG: KCSAN: data-race in data_push_tail / vsnprintf write to 0xffffffff88e3c607 of 18 bytes by task 12917 on cpu 1: vsnprintf+0x2ce/0x890 lib/vsprintf.c:2878 vscnprintf+0x41/0x90 lib/vsprintf.c:2991 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2216 vprintk_store+0x599/0x860 kernel/printk/printk.c:2336 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 validate_nla lib/nlattr.c:414 [inline] __nla_validate_parse+0x1227/0x1d00 lib/nlattr.c:635 __nla_parse+0x40/0x60 lib/nlattr.c:732 nla_parse_nested_deprecated include/net/netlink.h:1379 [inline] bpf_parse_prog+0x74/0x180 net/core/lwt_bpf.c:345 bpf_build_state+0x170/0x330 net/core/lwt_bpf.c:404 lwtunnel_build_state+0x124/0x200 net/core/lwtunnel.c:137 fib_nh_common_init+0xaa/0x260 net/ipv4/fib_semantics.c:628 fib_nh_init+0x67/0x1a0 net/ipv4/fib_semantics.c:654 fib_create_info+0xedd/0x1980 net/ipv4/fib_semantics.c:1442 fib_table_insert+0x60/0xeb0 net/ipv4/fib_trie.c:1212 inet_rtm_newroute+0xab/0x140 net/ipv4/fib_frontend.c:929 rtnetlink_rcv_msg+0x5fe/0x6d0 net/core/rtnetlink.c:6946 netlink_rcv_skb+0x120/0x220 net/netlink/af_netlink.c:2552 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6973 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5c0/0x690 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x58b/0x6b0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x142/0x180 net/socket.c:729 ____sys_sendmsg+0x31e/0x4e0 net/socket.c:2614 ___sys_sendmsg+0x17b/0x1d0 net/socket.c:2668 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2703 x64_sys_call+0x191e/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:47 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 0xffffffff88e3c618 of 8 bytes by task 29 on cpu 0: data_make_reusable kernel/printk/printk_ringbuffer.c:594 [inline] data_push_tail+0xfd/0x420 kernel/printk/printk_ringbuffer.c:679 data_alloc+0xbf/0x2b0 kernel/printk/printk_ringbuffer.c:1054 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:463 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 value changed: 0x0000000100003459 -> 0x206e612073616820 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 29 Comm: kauditd 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 ================================================================== audit: type=1326 audit(5796151601.958:47393): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=12914 comm="syz.2.12316" exe="/root/syz-executor" sig=0 arch=c000003e syscall=321 compat=0 ip=0x7f29d96debe9 code=0x7ffc0000 audit: type=1326 audit(5796151601.958:47394): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=12914 comm="syz.2.12316" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f29d96debe9 code=0x7ffc0000 audit: type=1326 audit(5796151601.958:47395): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=12914 comm="syz.2.12316" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f29d96debe9 code=0x7ffc0000 audit: type=1326 audit(5796151601.958:47396): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=12914 comm="syz.2.12316" exe="/root/syz-executor" sig=0 arch=c000003e syscall=321 compat=0 ip=0x7f29d96debe9 code=0x7ffc0000 audit: type=1326 audit(5796151601.988:47397): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=12914 comm="syz.2.12316" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f29d96debe9 code=0x7ffc0000 audit: type=1326 audit(5796151601.988:47398): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=12914 comm="syz.2.12316" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f29d96debe9 code=0x7ffc0000 audit: type=1326 audit(5796151601.988:47399): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=12914 comm="syz.2.12316" exe="/root/syz-executor" sig=0 arch=c000003e syscall=321 compat=0 ip=0x7f29d96debe9 code=0x7ffc0000