9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 ================================================================== BUG: KCSAN: data-race in data_push_tail / vsnprintf write to 0xffffffff893a1708 of 12 bytes by task 29601 on cpu 1: vsnprintf+0x2ce/0x860 lib/vsprintf.c:2899 vscnprintf+0x41/0x90 lib/vsprintf.c:3013 printk_sprint+0x30/0x2b0 kernel/printk/printk.c:2222 vprintk_store+0x57b/0x910 kernel/printk/printk.c:2364 vprintk_emit+0x1a4/0x600 kernel/printk/printk.c:2455 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2504 p9_fd_create_tcp+0x3da/0x430 net/9p/trans_fd.c:921 p9_client_create+0x231/0x770 net/9p/client.c:894 v9fs_session_init+0x3c/0x4a0 fs/9p/v9fs.c:442 v9fs_get_tree+0x5c/0x5e0 fs/9p/vfs_super.c:97 vfs_get_tree+0x57/0x1d0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x288/0x8d0 fs/namespace.c:3834 path_mount+0x4d0/0xbc0 fs/namespace.c:4154 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4360 __x64_sys_mount+0x67/0x80 fs/namespace.c:4360 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff893a1708 of 8 bytes by task 29597 on cpu 0: data_make_reusable kernel/printk/printk_ringbuffer.c:608 [inline] data_push_tail+0x100/0x470 kernel/printk/printk_ringbuffer.c:693 data_alloc+0x11b/0x390 kernel/printk/printk_ringbuffer.c:1089 prb_reserve+0x8d7/0xae0 kernel/printk/printk_ringbuffer.c:1724 vprintk_store+0x54a/0x910 kernel/printk/printk.c:2354 vprintk_emit+0x1a4/0x600 kernel/printk/printk.c:2455 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2504 p9_fd_create_tcp+0x3da/0x430 net/9p/trans_fd.c:921 p9_client_create+0x231/0x770 net/9p/client.c:894 v9fs_session_init+0x3c/0x4a0 fs/9p/v9fs.c:442 v9fs_get_tree+0x5c/0x5e0 fs/9p/vfs_super.c:97 vfs_get_tree+0x57/0x1d0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x288/0x8d0 fs/namespace.c:3834 path_mount+0x4d0/0xbc0 fs/namespace.c:4154 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4360 __x64_sys_mount+0x67/0x80 fs/namespace.c:4360 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00000001000019a5 -> 0x5f74656e70393301 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 29597 Comm: syz.0.5471 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 ================================================================== 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1 9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1