audit: type=1326 audit(1729758367.563:5080): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=8340 comm="syz.1.1644" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f22dc22dff9 code=0x7ffc0000 audit: type=1326 audit(1729758367.563:5081): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=8340 comm="syz.1.1644" exe="/root/syz-executor" sig=0 arch=c000003e syscall=321 compat=0 ip=0x7f22dc22dff9 code=0x7ffc0000 ================================================================== BUG: KCSAN: data-race in data_push_tail / vsnprintf write to 0xffffffff88bc0d37 of 1 bytes by task 8333 on cpu 0: vsnprintf+0xdd8/0xe30 vscnprintf+0x42/0x90 lib/vsprintf.c:2909 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2197 vprintk_store+0x570/0x810 kernel/printk/printk.c:2311 vprintk_emit+0x15e/0x680 kernel/printk/printk.c:2383 vprintk_default+0x26/0x30 kernel/printk/printk.c:2422 vprintk+0x75/0x80 kernel/printk/printk_safe.c:68 _printk+0x7a/0xa0 kernel/printk/printk.c:2432 chnl_net_open+0x525/0x5a0 __dev_open+0x1f7/0x2e0 net/core/dev.c:1476 __dev_change_flags+0x155/0x410 net/core/dev.c:8841 dev_change_flags+0x59/0xd0 net/core/dev.c:8913 do_setlink+0x844/0x2490 net/core/rtnetlink.c:2929 rtnl_group_changelink net/core/rtnetlink.c:3476 [inline] __rtnl_newlink net/core/rtnetlink.c:3735 [inline] rtnl_newlink+0xbc6/0x1690 net/core/rtnetlink.c:3772 rtnetlink_rcv_msg+0x6aa/0x710 net/core/rtnetlink.c:6675 netlink_rcv_skb+0x12c/0x230 net/netlink/af_netlink.c:2551 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6693 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] netlink_unicast+0x599/0x670 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x5cc/0x6e0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg+0x140/0x180 net/socket.c:744 ____sys_sendmsg+0x312/0x410 net/socket.c:2607 ___sys_sendmsg net/socket.c:2661 [inline] __sys_sendmsg+0x1d9/0x270 net/socket.c:2690 __do_sys_sendmsg net/socket.c:2699 [inline] __se_sys_sendmsg net/socket.c:2697 [inline] __x64_sys_sendmsg+0x46/0x50 net/socket.c:2697 x64_sys_call+0x2689/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff88bc0d30 of 8 bytes by task 29 on cpu 1: data_make_reusable kernel/printk/printk_ringbuffer.c:594 [inline] data_push_tail+0x102/0x430 kernel/printk/printk_ringbuffer.c:679 data_alloc+0xbe/0x2c0 kernel/printk/printk_ringbuffer.c:1054 prb_reserve+0x85e/0xb60 kernel/printk/printk_ringbuffer.c:1669 vprintk_store+0x53f/0x810 kernel/printk/printk.c:2301 vprintk_emit+0x15e/0x680 kernel/printk/printk.c:2383 vprintk_default+0x26/0x30 kernel/printk/printk.c:2422 vprintk+0x75/0x80 kernel/printk/printk_safe.c:68 _printk+0x7a/0xa0 kernel/printk/printk.c:2432 kauditd_printk_skb kernel/audit.c:546 [inline] kauditd_hold_skb+0x1a3/0x1b0 kernel/audit.c:581 kauditd_send_queue+0x288/0x2e0 kernel/audit.c:766 kauditd_thread+0x42a/0x650 kernel/audit.c:890 kthread+0x1d1/0x210 kernel/kthread.c:389 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 value changed: 0x00000000ffffebc6 -> 0x000a646564657463 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 29 Comm: kauditd Tainted: G W 6.12.0-rc4-syzkaller-00047-gc2ee9f594da8 #0 Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 ================================================================== kauditd_printk_skb: 15 callbacks suppressed audit: type=1400 audit(1729758372.073:5097): avc: denied { read } for pid=2953 comm="syslogd" name="log" dev="sda1" ino=1915 scontext=system_u:system_r:syslogd_t tcontext=system_u:object_r:var_t tclass=lnk_file permissive=1 audit: type=1400 audit(1729758372.073:5098): avc: denied { search } for pid=2953 comm="syslogd" name="/" dev="tmpfs" ino=1 scontext=system_u:system_r:syslogd_t tcontext=system_u:object_r:tmpfs_t tclass=dir permissive=1 audit: type=1400 audit(1729758372.073:5099): avc: denied { append } for pid=2953 comm="syslogd" name="messages" dev="tmpfs" ino=6 scontext=system_u:system_r:syslogd_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1 audit: type=1400 audit(1729758372.073:5100): avc: denied { open } for pid=2953 comm="syslogd" path="/tmp/messages" dev="tmpfs" ino=6 scontext=system_u:system_r:syslogd_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1 audit: type=1400 audit(1729758372.073:5101): avc: denied { getattr } for pid=2953 comm="syslogd" path="/tmp/messages" dev="tmpfs" ino=6 scontext=system_u:system_r:syslogd_t tcontext=system_u:object_r:tmpfs_t tclass=file permissive=1