9pnet_fd: Insufficient options for proto=fd
==================================================================
BUG: KCSAN: data-race in console_flush_all / console_flush_all

write to 0xffffffff86a20c28 of 8 bytes by task 20870 on cpu 0:
 console_emit_next_record kernel/printk/printk.c:3099 [inline]
 console_flush_all+0x35a/0x730 kernel/printk/printk.c:3226
 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
 console_unlock+0xa1/0x330 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
 chnl_net_open+0x2a9/0x560 net/caif/chnl_net.c:260
 __dev_open+0x2d2/0x530 net/core/dev.c:1682
 __dev_change_flags+0x163/0x400 net/core/dev.c:9549
 netif_change_flags+0x5a/0xd0 net/core/dev.c:9612
 do_setlink+0x9d2/0x2810 net/core/rtnetlink.c:3143
 rtnl_group_changelink net/core/rtnetlink.c:3775 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3929 [inline]
 rtnl_newlink+0xd8b/0x12d0 net/core/rtnetlink.c:4057
 rtnetlink_rcv_msg+0x5fb/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 0xffffffff86a20c28 of 8 bytes by task 20874 on cpu 1:
 console_flush_all+0x563/0x730 kernel/printk/printk.c:3227
 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
 console_unlock+0xa1/0x330 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
 p9_fd_create+0x20c/0x280 net/9p/trans_fd.c:1093
 p9_client_create+0x60b/0xbc0 net/9p/client.c:1017
 v9fs_session_init+0xf7/0xde0 fs/9p/v9fs.c:410
 v9fs_mount+0x67/0x5c0 fs/9p/vfs_super.c:122
 legacy_get_tree+0x75/0xd0 fs/fs_context.c:666
 vfs_get_tree+0x54/0x1d0 fs/super.c:1815
 do_new_mount+0x207/0x5e0 fs/namespace.c:3808
 path_mount+0x4a4/0xb20 fs/namespace.c:4123
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4324
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4324
 x64_sys_call+0x2b4d/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:166
 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: 0x0000000000003401 -> 0x0000000000003402

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 20874 Comm: syz.0.6568 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
==================================================================