Boot error since 6.9: Initramfs unpacking failed: invalid magic at start of compressed archive

[Thorsten Leemhuis]

Hi, Thorsten here, the Linux kernel's regression tracker.

I noticed a report about a regression in bugzilla.kernel.org that a user
bisected to the main ARM64 merge commit from the 6.9 cycle. So the real
issue might be somewhere else, but some help would be appreciated. To
quote from https://bugzilla.kernel.org/show_bug.cgi?id=219014 :

> Hi.
> 
> I'm marking as arm64 since git bisect identifies the first problematic commit as:
>   6d75c6f40a03c97e1ecd683ae54e249abb9d922b
> 
> git bisect log is attached.
> 
> Any kernel tagged v6.9x and later fails to boot with the following error:
> 
> [    0.420154] Initramfs unpacking failed: invalid magic at start of compressed archive
> [    0.433178] Freeing initrd memory: 8820K
> ... snip ...
> [    0.701958] List of all partitions:
> [    0.705604] No filesystem could mount root, tried: 
> [    0.705608] 
> [    0.712166] Kernel panic - not syncing: VFS: Unable to mount root fs on "UUID=a889afec-1ced-4493-ab8b-cf1569819c49" or unknown-block(0,0)                                                
> [    0.724903] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.9.8-sheeva64 #sheeva64
> [    0.732356] Hardware name: gti sheeva64 development board (DT)
> [    0.738369] Call trace:
> 
> full start-up log attached.
> 
> kernel 6.8.12 and earlier builds boot no problem. 
> 
> Info:
> 
> - hardware: sheeva64 plug (Marvell Armada 3720 dual core ARMv8 Cortex-A53)
> - uboot version: U-Boot 2017.03-armada-18.09.1-gc338309136
>   - uboot init script with kernel cmdline is attached (I haven't changed this in at least a few years)
> - ext4 rootfs is on external usb drive
> - kernel 6.8.12 and earlier boot without issue (see attached: .config.6.8.12)
> - problem first seen in commit: 6d75c6f40a03c97e1ecd683ae54e249abb9d922b (see attached: git_bisect.log)
> - any kernel tagged 6.9x and later that I've tried fails with above error (see attached: .config.6.9.8.broken)
> - I'm building the kernel by cross-compiling on debian "testing" (`crossbuild-essential-arm64`)
> - the `initrd.img-6.9x` file itself appears valid:
>   - `lsinitramfs` works no problem
>   - `file initrd.img-6.9x` output is the same as the working initrds (`Zstandard compressed data (v0.8+), Dictionary ID: None`)
> 
> The bisected commit 6d75c6f40a03c97e1ecd683ae54e249abb9d922b is a merge of some 130+ arm64-related commits, so I'm having a hard time narrowing this down further. I'm glad to help test/troubleshoot but I'd need someone to give me some pointers.
> 
> thanks.
> 
> Jack Donohue

See the ticket for more details.

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
--
Everything you wanna know about Linux kernel regression tracking:
https://linux-regtracking.leemhuis.info/about/#tldr
If I did something stupid, please tell me, as explained on that page.

P.S.: let me use this mail to also add the report to the list of tracked
regressions to ensure it's doesn't fall through the cracks:

#regzbot introduced: 6d75c6f40a03c97e1ecd683ae54e249abb9d922b
#regzbot title: arm64: Initramfs unpacking failed: invalid magic at
start of compressed archive
#regzbot from: Jack D <wm2vdghq at duck.com>
#regzbot duplicate: https://bugzilla.kernel.org/show_bug.cgi?id=219014
#regzbot ignore-activity