From: Jeff King <peff@peff.net>
To: git@vger.kernel.org
Subject: [PATCH 0/6] harden tree-walking against integer overflow
Date: Wed, 31 Jul 2019 00:37:00 -0400 [thread overview]
Message-ID: <20190731043659.GA27028@sigill.intra.peff.net> (raw)
I noticed that it's possible to get funny integer over/underflows with
tree-walk's traverse_info (with specially-crafted absurdly-sized tree
paths). I wasn't able to turn this into an actual buffer overflow
because the funky sizes cause allocation failures way before we ever get
into make_traverse_path(). But it makes sense to protect ourselves
anyway.
The first two patches are an unrelated memory problem I found (and
they're here in the same series because I build on the cleanups). I
don't think it's security-relevant, though; it involves reading from
uninitialized heap memory, but we don't actually _do_ anything with the
result. We just copy uninitialized bytes from one heap buffer to the
other, and then never look at them again.
[1/6]: setup_traverse_info(): stop copying oid
[2/6]: tree-walk: drop oid from traverse_info
[3/6]: tree-walk: use size_t consistently
[4/6]: tree-walk: accept a raw length for traverse_path_len()
[5/6]: tree-walk: add a strbuf wrapper for make_traverse_path()
[6/6]: tree-walk: harden make_traverse_path() length computations
Documentation/technical/api-tree-walking.txt | 8 ++-
builtin/merge-tree.c | 5 +-
cache-tree.c | 2 +-
tree-walk.c | 64 +++++++++++------
tree-walk.h | 18 +++--
unpack-trees.c | 74 +++++++++++---------
6 files changed, 103 insertions(+), 68 deletions(-)
-Peff
next reply other threads:[~2019-07-31 4:37 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-31 4:37 Jeff King [this message]
2019-07-31 4:38 ` [PATCH 1/6] setup_traverse_info(): stop copying oid Jeff King
2019-07-31 4:38 ` [PATCH 2/6] tree-walk: drop oid from traverse_info Jeff King
2019-07-31 4:38 ` [PATCH 3/6] tree-walk: use size_t consistently Jeff King
2019-08-01 18:17 ` Derrick Stolee
2019-07-31 4:38 ` [PATCH 4/6] tree-walk: accept a raw length for traverse_path_len() Jeff King
2019-07-31 4:38 ` [PATCH 5/6] tree-walk: add a strbuf wrapper for make_traverse_path() Jeff King
2019-07-31 4:38 ` [PATCH 6/6] tree-walk: harden make_traverse_path() length computations Jeff King
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