corrupt object memory allocation error

I've got a git repository of < 2 mb, where git wants to
allocate a rather insane amount of memory:

git fsck

Checking object directories: 100% (256/256), done.
fatal: Out of memory, malloc failed (tried to allocate 124865231165 bytes)

git show 11644b5a075dc1425e01fbba51c045cea2d0c408

fatal: Out of memory, malloc failed (tried to allocate 124865231165 bytes)

The problem seems to be the attached object file, which has gotten
corrupted, presumably in the header that git reads to see how large it
is. Thought I'd report this in case there is some easy way to
add a sanity check.

-- 
see shy jo