syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 ================================================================== BUG: KCSAN: data-race in data_alloc / prb_reserve write to 0xffffffff8686c208 of 8 bytes by task 31331 on cpu 0: 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 __netdev_printk+0x321/0x3e0 net/core/dev.c:12588 netdev_info+0x9b/0xd0 net/core/dev.c:12635 tun_net_xmit+0x4f2/0xb40 drivers/net/tun.c:1024 __netdev_start_xmit include/linux/netdevice.h:5219 [inline] netdev_start_xmit include/linux/netdevice.h:5228 [inline] xmit_one net/core/dev.c:3827 [inline] dev_hard_start_xmit+0x125/0x3e0 net/core/dev.c:3843 sch_direct_xmit+0x192/0x550 net/sched/sch_generic.c:344 __dev_xmit_skb net/core/dev.c:4102 [inline] __dev_queue_xmit+0xe9a/0x2000 net/core/dev.c:4679 dev_queue_xmit include/linux/netdevice.h:3358 [inline] neigh_hh_output include/net/neighbour.h:531 [inline] neigh_output include/net/neighbour.h:545 [inline] ip_finish_output2+0x77f/0x8b0 net/ipv4/ip_output.c:235 __ip_finish_output net/ipv4/ip_output.c:-1 [inline] ip_finish_output+0x114/0x2a0 net/ipv4/ip_output.c:323 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0xbd/0x190 net/ipv4/ip_output.c:436 dst_output include/net/dst.h:461 [inline] ip_local_out net/ipv4/ip_output.c:129 [inline] ip_send_skb+0x12c/0x160 net/ipv4/ip_output.c:1506 udp_send_skb+0x6e3/0xa40 net/ipv4/udp.c:1195 udp_sendmsg+0x1050/0x13c0 net/ipv4/udp.c:1484 inet_sendmsg+0xac/0xd0 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x102/0x180 net/socket.c:729 ____sys_sendmsg+0x345/0x4e0 net/socket.c:2614 ___sys_sendmsg+0x17b/0x1d0 net/socket.c:2668 __sys_sendmmsg+0x178/0x300 net/socket.c:2757 __do_sys_sendmmsg net/socket.c:2784 [inline] __se_sys_sendmmsg net/socket.c:2781 [inline] __x64_sys_sendmmsg+0x57/0x70 net/socket.c:2781 x64_sys_call+0x1c4a/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:308 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 0xffffffff8686c208 of 8 bytes by task 31361 on cpu 1: 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 __netdev_printk+0x321/0x3e0 net/core/dev.c:12588 netdev_info+0x9b/0xd0 net/core/dev.c:12635 tun_net_xmit+0x4f2/0xb40 drivers/net/tun.c:1024 __netdev_start_xmit include/linux/netdevice.h:5219 [inline] netdev_start_xmit include/linux/netdevice.h:5228 [inline] xmit_one net/core/dev.c:3827 [inline] dev_hard_start_xmit+0x125/0x3e0 net/core/dev.c:3843 sch_direct_xmit+0x192/0x550 net/sched/sch_generic.c:344 __dev_xmit_skb net/core/dev.c:4102 [inline] __dev_queue_xmit+0xe9a/0x2000 net/core/dev.c:4679 dev_queue_xmit include/linux/netdevice.h:3358 [inline] neigh_hh_output include/net/neighbour.h:531 [inline] neigh_output include/net/neighbour.h:545 [inline] ip_finish_output2+0x77f/0x8b0 net/ipv4/ip_output.c:235 __ip_finish_output net/ipv4/ip_output.c:-1 [inline] ip_finish_output+0x114/0x2a0 net/ipv4/ip_output.c:323 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0xbd/0x190 net/ipv4/ip_output.c:436 dst_output include/net/dst.h:461 [inline] ip_local_out net/ipv4/ip_output.c:129 [inline] ip_send_skb+0x12c/0x160 net/ipv4/ip_output.c:1506 udp_send_skb+0x6e3/0xa40 net/ipv4/udp.c:1195 udp_sendmsg+0x1050/0x13c0 net/ipv4/udp.c:1484 inet_sendmsg+0xac/0xd0 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x102/0x180 net/socket.c:729 ____sys_sendmsg+0x345/0x4e0 net/socket.c:2614 ___sys_sendmsg+0x17b/0x1d0 net/socket.c:2668 __sys_sendmmsg+0x178/0x300 net/socket.c:2757 __do_sys_sendmmsg net/socket.c:2784 [inline] __se_sys_sendmmsg net/socket.c:2781 [inline] __x64_sys_sendmmsg+0x57/0x70 net/socket.c:2781 x64_sys_call+0x1c4a/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:308 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 value changed: 0x00000000001ecf40 -> 0x0000000000269328 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 31361 Comm: syz.2.19732 Tainted: G W 6.17.0-rc1-syzkaller-00016-g8742b2d8935f #0 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 ================================================================== syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42 syz_tun: tun_net_xmit 42