Re: [PATCH] fetch-pack: disregard invalid pack lockfiles

From: René Scharfe <l.s.r@web.de>
Date: Nov 30, 2020, 20:15 UTC
Message-ID: <67cf2f10-43a4-1200-0c60-dada466eadb9@web.de>
In-Reply-To: <X8VNszeQKJPfZ+Ht@nand.local>

Am 30.11.20 um 20:53 schrieb Taylor Blau:

Show 12 quoted lines

> On Mon, Nov 30, 2020 at 08:27:15PM +0100, René Scharfe wrote:
>> index_pack_lockfile() can return NULL if it doesn't like the contents it
>> reads from the file descriptor passed to it.  unlink(2) is declared to
>> not accept NULL pointers (at least with glibc).  Undefined Behavior
>> Sanitizer together with Address Sanitizer detects a case where a NULL
>> lockfile name is passed to unlink(2) by transport_unlock_pack() in t1060
>> (make SANITIZE=address,undefined; cd t; ./t1060-object-corruption.sh).
>
> Which test in t1060? I tried to reproduce this myself, but couldn't seem
> to coax out a failure. (Initially I thought that my ccache wasn't
> letting me recompile with the SANITIZE options, but running 'ccache
> clear' and then trying again left the test still passing).

15 - fetch into corrupted repo with index-pack

   $ cat trash\ directory.t1060-object-corruption/bit-error-cp/stderr
   error: inflate: data stream error (invalid distance too far back)
   error: unable to unpack d95f3ad14dee633a758d2e331151e950dd13e4ed header
   fatal: cannot read existing object info d95f3ad14dee633a758d2e331151e950dd13e4ed
   fatal: index-pack failed
   wrapper.c:568:52: runtime error: null pointer passed as argument 1, which is declared to never be null
   /usr/include/unistd.h:825:48: note: nonnull attribute specified here
   SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior wrapper.c:568:52 in
   Aborted

Compiled with:
   Debian clang version 11.0.0-5+b1
   Target: x86_64-pc-linux-gnu
   Thread model: posix
   InstalledDir: /usr/bin

René