=====================================================
BUG: KMSAN: uninit-value in map_id_up_base kernel/user_namespace.c:335 [inline]
BUG: KMSAN: uninit-value in map_id_up kernel/user_namespace.c:365 [inline]
BUG: KMSAN: uninit-value in from_kuid+0x51d/0xbd0 kernel/user_namespace.c:413
 map_id_up_base kernel/user_namespace.c:335 [inline]
 map_id_up kernel/user_namespace.c:365 [inline]
 from_kuid+0x51d/0xbd0 kernel/user_namespace.c:413
 p9pdu_vwritef+0x15ab/0x5120 net/9p/protocol.c:398
 p9pdu_writef+0x23a/0x280 net/9p/protocol.c:539
 p9pdu_vwritef+0x21f0/0x5120 net/9p/protocol.c:490
 p9_client_prepare_req+0x9e3/0x1090 net/9p/client.c:703
 p9_client_rpc+0x276/0x1460 net/9p/client.c:734
 p9_client_setattr+0x115/0x2c0 net/9p/client.c:1894
 v9fs_vfs_setattr_dotl+0x7e2/0xd70 fs/9p/vfs_inode_dotl.c:588
 notify_change+0x1fe3/0x2170 fs/attr.c:410
 vfs_utimes+0x8aa/0xc70 fs/utimes.c:65
 do_utimes_path fs/utimes.c:98 [inline]
 do_utimes+0x4d7/0x6d0 fs/utimes.c:144
 do_compat_futimesat+0x535/0x670 fs/utimes.c:284
 __do_sys_utimes_time32 fs/utimes.c:296 [inline]
 __se_sys_utimes_time32 fs/utimes.c:294 [inline]
 __ia32_sys_utimes_time32+0x9d/0xd0 fs/utimes.c:294
 do_syscall_32_irqs_on arch/x86/entry/common.c:114 [inline]
 __do_fast_syscall_32+0x96/0xf0 arch/x86/entry/common.c:180
 do_fast_syscall_32+0x34/0x70 arch/x86/entry/common.c:205
 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:248
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

Uninit was stored to memory at:
 v9fs_vfs_setattr_dotl+0x58a/0xd70 fs/9p/vfs_inode_dotl.c:565
 notify_change+0x1fe3/0x2170 fs/attr.c:410
 vfs_utimes+0x8aa/0xc70 fs/utimes.c:65
 do_utimes_path fs/utimes.c:98 [inline]
 do_utimes+0x4d7/0x6d0 fs/utimes.c:144
 do_compat_futimesat+0x535/0x670 fs/utimes.c:284
 __do_sys_utimes_time32 fs/utimes.c:296 [inline]
 __se_sys_utimes_time32 fs/utimes.c:294 [inline]
 __ia32_sys_utimes_time32+0x9d/0xd0 fs/utimes.c:294
 do_syscall_32_irqs_on arch/x86/entry/common.c:114 [inline]
 __do_fast_syscall_32+0x96/0xf0 arch/x86/entry/common.c:180
 do_fast_syscall_32+0x34/0x70 arch/x86/entry/common.c:205
 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:248
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

Local variable newattrs created at:
 vfs_utimes+0x69/0xc70 fs/utimes.c:22
 do_utimes_path fs/utimes.c:98 [inline]
 do_utimes+0x4d7/0x6d0 fs/utimes.c:144

CPU: 0 PID: 9758 Comm: syz-executor.3 Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
=====================================================