udevadm: Failed to scan devices: Input/output error

Hi experts,

I have a problem at hand that I've found pretty hard to debug and seems like I've hit a road block with this. I have a system running kernel v5.10.82 with SELinux, systemd v244. The system used to boot just fine until for some usecases I had to enable the following kernel configurations.

CONFIG_USER_NS=y
CONFIG_BLK_CGROUP=y
CONFIG_CGROUP_WRITEBACK=y
CONFIG_CGROUP_SCHED=y
CONFIG_CGROUP_FREEZER=y
CONFIG_CGROUP_DEVICE=y
CONFIG_CGROUP_CPUACCT=y
CONFIG_NF_NAT_MASQUERADE=y
CONFIG_OVERLAY_FS=y
CONFIG_OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW=y
CONFIG_IP_NF_NAT=m
CONFIG_IP_NF_TARGET_MASQUERADE=m
CONFIG_CGROUP_SCHED=y
CONFIG_CPUSETS=y
CONFIG_CHECKPOINT_RESTORE=y
CONFIG_MEMCG=y
CONFIG_MEMCG_SWAP=y
CONFIG_MEMCG_KMEM=y
CONFIG_OPENVSWITCH=m
CONFIG_OPENVSWITCH_VXLAN=m
CONFIG_MPLS=y
CONFIG_NET_MPLS_GSO=m
CONFIG_NET_NSH=m
CONFIG_NETFILTER_XT_NAT=m
CONFIG_NETFILTER_XT_TARGET_MASQUERADE=m
CONFIG_NETFILTER_XT_MATCH_ADDRTYPE=m

Now, the system boots just fine on some attempts while on others it takes quite a lot of time to boot with logs such as

Starting version 244
Failed to scan devices: Input/output error
  WARNING: Device /dev/ram0 not initialized in udev database even after waiting 10000000 microseconds.
  WARNING: Device /dev/mmcblk0 not initialized in udev database even after waiting 10000000 microseconds.
  WARNING: Device /dev/ram1 not initialized in udev database even after waiting 10000000 microseconds.
  WARNING: Device /dev/mmcblk0p1 not initialized in udev database even after waiting 10000000 microseconds.

  ...

  ...

I noticed the "Failed to scan devices" and enabled systemd debug using the kernel command line with

systemd.log_level=debug systemd.log_target=kmsg log_buf_len=1M printk.devkmsg=on

and got

udevadm[433]: Failed to scan devices: Input/output error

There are no AVC denials seen and running SELinux in permissive mode makes no difference, I still see failing/lazy boots, however if I disable SELinux (selinux=0) altogether everything starts up cleanly. On a boot where such hiccups are seen running systemd-udev-trigger even after login fails with the same input/output error.

Any pointers on why udevadm might run into an input/output error could get me going here. Help will be much appreciated.