DO NOT FLASH OR WIPE USING ANY ICS REPACK
The list of "known safe" kernels is below in this post - there are currently two known-safe ICS kernels, but only two.
These kernels are fundamentally dangerous. Samsung introduced some sort of bug in the eMMC driver that can permanently damage the eMMC flash storage of the phone. This leads to unusable partitions at best, and at worst a hardbricked device. The nature of the failure is so severe that the usual method for hardbrick recovery (JTAG) is unable to recover devices damaged in this manner.
Kernels that have been confirmed affected are:
All ICS leaks for the Samsung Epic 4G Touch (SPH-D710)
All ICS leaks for the Samsung Galaxy Note (GT-N7000)
XXLPY official ICS release for GT-N7000 - at least one hardbrick (chasmodo), 2 people with damaged partitions (unusable /data or /system), at least 1 person with unusable /data after a wipe in *factory* recovery - it's not just CWM, and one person who hardbricked after wiping in Settings
ZSLPF official ICS release for GT-N7000 - http://forum.xda-developers.com/show....php?t=1661590 and http://forum.xda-developers.com/show...1#post26275391 are the first two reports.
UCLD3 ICS leak for the AT&T Samsung Galaxy S II (SGH-I777) - Other leaks may also be affected
Kernels built using the most recent SHW-M250S/K/L official source code release as of May 3, 2012 - This includes SiyahKernel 3.1rc6 for GT-I9100 (all other Siyah releases are safe)
Damage is not guaranteed - it may only affect a small percentage of users, but even a 5% chance is far more dangerous than the effectively 0% chance of hardbricking due to kernel bugs in safe kernels.
Also, some people will not fully hardbrick - /data or /system will become unwritable, resulting in a phone that can enter download mode, can flash kernels, can write to some partitions in recovery, but is overall unusable due to one or more critical partitions being unusable.
Kernels that have been confirmed safe:
All known Gingerbread kernels for the Galaxy Note and other affected devices listed above
Kernels built from the GT-I9100 Update4 source code release - this includes XplodWILD's CM9 release and my DAFUQ release, hopefully more kernel choices will become available soon
Kernels that have had MMC_CAP_ERASE disabled in mshci.c should be safe, look for it in the listed features of the kernel - preliminary results are good, no bricks have been reported by anyone confirmed to be actually running such a kernel yet.
If you are running an affected kernel:
STOP USING IT IMMEDIATELY. FLASH A SAFE KERNEL USING ODIN/HEIMDALL.
DO NOT wipe in recovery
DO NOT flash anything else in recovery
In general, DO NOT use recovery at all
Right now, what we know:
Some people can wipe with affected kernels as often as they want without problems. Just because you didn't brick, DO NOT advise other users that they will be OK.
Based on reports from the Epic 4G Touch community, some people can wipe/flash 20-30 times before hardbricking - Just because you didn't brick once, DO NOT continue flashing with an affected kernel
The source of the problem is somewhere within the changes between I9100 Update4 and SHW-M250S Update5 - https://github.com/Entropy512/kernel...250s_dangerous
What we don't know:
Exactly which source commit above is responsible
How to determine if a future kernel or source release is safe without putting user's devices at risk - You only need to reproduce the problem once to be hosed.