audit: type=1326 audit(1747183605.389:23478): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=28026 comm="syz.5.7849" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f34f686e969 code=0x7ffc0000 ================================================================== BUG: KCSAN: data-race in data_alloc / prb_reserve write to 0xffffffff86897498 of 8 bytes by task 28033 on cpu 1: data_alloc+0x27d/0x2b0 kernel/printk/printk_ringbuffer.c:1096 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 caif_disconnect_client+0x13d/0x150 net/caif/cfcnfg.c:194 chnl_net_open+0x4c6/0x560 net/caif/chnl_net.c:326 __dev_open+0x2d5/0x530 net/core/dev.c:1629 __dev_change_flags+0x163/0x400 net/core/dev.c:9354 netif_change_flags+0x5a/0xd0 net/core/dev.c:9417 do_setlink+0x90e/0x27f0 net/core/rtnetlink.c:3152 rtnl_group_changelink net/core/rtnetlink.c:3783 [inline] __rtnl_newlink net/core/rtnetlink.c:3937 [inline] rtnl_newlink+0xd8b/0x12d0 net/core/rtnetlink.c:4065 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+0x5a1/0x670 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 read to 0xffffffff86897498 of 8 bytes by task 29 on cpu 0: 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+0x221/0xaf0 kernel/printk/printk_ringbuffer.c:1619 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+0x489/0x510 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 value changed: 0x0000000000074cc0 -> 0x0000000000132138 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 29 Comm: kauditd Not tainted 6.15.0-rc6-syzkaller-00051-g405e6c37c89e #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 ================================================================== audit: type=1326 audit(1747183605.389:23479): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=28026 comm="syz.5.7849" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f34f686e969 code=0x7ffc0000