Re: [PATCH] Don't segfault if we failed to inflate a packed delta

From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Aug 25, 2007, 15:19 UTC
Message-ID: <alpine.LFD.0.999.0708250815150.25853@woody.linux-foundation.org>
In-Reply-To: <20070825072604.GA20155@spearce.org>

On Sat, 25 Aug 2007, Shawn O. Pearce wrote:

Show 8 quoted lines

> 
> cate on #git noticed this failure in `git fsck --full` where the
> call to verify_pack() first noticed that the packfile was corrupt
> by finding that the packfile's SHA-1 did not match the raw data of
> the file.  After finding this fsck went ahead and tried to verify
> every object within the packfile, even though the packfile was
> already known to be bad.  If we are going to shovel bad data at
> the delta unpacking code, we better handle it correctly.

Hmm. We should actually make "unpack_entry()" return print an error and return NULL for these cases, rather than die, I think.

Most of the callers seem to already check for NULL (not "load_tree()" in fast-import.c), but for something like fsck, while "die()" is obviously better than a SIGSEGV, we should probably continue and try to see what else we find.

(Although, to be honest, it might not matter. If your pack-file is corrupt enough for this to trigger, there's seldom anything interesting fsck will tell, so in practical terms this probably isn't a big deal).

		Linus