Snapshot WRT32X: SQUASHFS error: xz decompression failed, data probably corrupt

For Developers
1

Device: Linksys WRT32x
Image File: https://downloads.openwrt.org/snapshots/targets/mvebu/cortexa9/openwrt-mvebu-cortexa9-linksys_wrt32x-squashfs-factory.img
Time: Tue Sep 24 21:25:32 2019
Sum: 52a91567312ea0f845dd15287ca665e19c3ab948efc93a55d22101df2caf747d

First boot gave me these errors. I rebooted a few times since, and I don't see the errors in 'dmesg' anymore.

[   16.352768] br-lan: port 1(eth0.1) entered forwarding state
[   16.358415] IPv6: ADDRCONF(NETDEV_UP): br-lan: link is not ready
[   16.367308] mvneta f1070000.ethernet eth1: configuring for fixed/rgmii-id link mode
[   16.375352] IPv6: ADDRCONF(NETDEV_UP): eth1: link is not ready
[   16.381293] mvneta f1070000.ethernet eth1: Link is Up - 1Gbps/Full - flow control off
[   16.389265] IPv6: ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready
[   17.351307] IPv6: ADDRCONF(NETDEV_CHANGE): br-lan: link becomes ready
[   17.487042] ICMPv6: process `sysctl' is using deprecated sysctl (syscall) net.ipv6.neigh.br-lan.base_reachable_time - use net.ipv6.neigh.br-lan.base_reachable_time_ms instead
[   18.816795] SQUASHFS error: xz decompression failed, data probably corrupt
[   18.823716] SQUASHFS error: squashfs_read_data failed to read block 0x27970e
[   18.844839] SQUASHFS error: xz decompression failed, data probably corrupt
[   18.851750] SQUASHFS error: squashfs_read_data failed to read block 0x27970e
[   18.874009] SQUASHFS error: xz decompression failed, data probably corrupt
[   18.880917] SQUASHFS error: squashfs_read_data failed to read block 0x27970e
[   18.903068] SQUASHFS error: xz decompression failed, data probably corrupt
[   18.909977] SQUASHFS error: squashfs_read_data failed to read block 0x27970e
[   18.932220] SQUASHFS error: xz decompression failed, data probably corrupt
[   18.939130] SQUASHFS error: squashfs_read_data failed to read block 0x27970e
[   18.961446] SQUASHFS error: xz decompression failed, data probably corrupt
2

Possibly a NAND block "went bad". While relatively rare to see, it is expected. "Raw" NAND flash reserves around 2% of the total blocks for remapping. nandtest can possibly shed some light on things, but even with the -k option to restore data, there's always a chance that it corrupts your data.

Another thing to consider is that the device's U-Boot detected enough boot failures, then switched over to the other firmware version.