# Resolved: Bit Flip Corruption in Cryptsetup Binary
## Summary
Bit flip corruption in cryptsetup binary causing segmentation fault during
boot. Regenerating the initramfs with a uncorrupted binary allows decryption
and normal boot.
## Description
A bit flip occurred in the cryptsetup binary within the initramfs, causing
segmentation faults and preventing successful LUKS decryption during boot. The
corruption was detected when comparing working and non-working initramfs images.
## Evidence of Corruption
# Extract both initramfs images
mkdir initrd.34 && cd initrd.34
unmkinitramfs /boot/initrd.img-6.14.0-34-generic .
cd ..
mkdir initrd.35 && cd initrd.35
unmkinitramfs /boot/initrd.img-6.14.0-35-generic .
cd ..
# Generate checksums
find initrd.34 -type f -exec md5sum {} \; > initrd-34.checksums.txt
find initrd.35 -type f -exec md5sum {} \; > initrd-35.checksums.txt
### Working vs Corrupted Binary
```
# Working initramfs (kernel 6.14.0-34):
$ /tmp/initrd.34/main/usr/sbin/cryptsetup --version
cryptsetup 2.7.5 flags: UDEV BLKID KEYRING FIPS KERNEL_CAPI HW_OPAL
# Corrupted initramfs (kernel 6.14.0-35):
$ /tmp/initrd.35/main/usr/sbin/cryptsetup --version
Segmentation fault (core dumped)
```
### Checksum Verification
```
# Checksum differences confirm binary corruption:
$ grep cryptsetup initrd-34.checksums.txt
8579c3e53069dfc5666e2a852e1bf8b1 ./main/usr/sbin/cryptsetup
$ grep cryptsetup initrd-35.checksums.txt
f143a736cc702efa927b5c87ba06a19d ./main/usr/sbin/cryptsetup
# Binary comparison confirms bit flip:
$ cmp -l initrd.34/main/usr/sbin/cryptsetup initrd.35/main/usr/sbin/cryptsetup
5540 0 4
```
## Solution:
### Regenerated initramfs image
```
$ sudo update-initramfs -d -k 6.14.0-35-generic
$ sudo update-initramfs -u -k 6.14.0-35-generic
$ sudo update-grub
```
Can now boot and decrypt my root partition using kernel
6.14.0-35-generic
** Changed in: ubuntu
Status: New => Invalid
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https://bugs.launchpad.net/bugs/2130368
Title:
Segmentation fault decrypting root partition when using kernel
6.14.0-35.35
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