From b6e9756ca03ec887ef1d0bc8e38f63c29db7a365 Mon Sep 17 00:00:00 2001 From: Julian Andres Klode Date: Tue, 28 Jun 2016 10:24:11 +0200 Subject: Fix buffer overflow in debListParser::VersionHash() If a package file is formatted in a way that that no space follows a deprecated "<", we would reformat it to "<=" and increase the length of the output by 1, which can break. Under normal circumstances with "<=" this should not be an issue. Closes: #828812 --- apt-pkg/deb/deblistparser.cc | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'apt-pkg/deb/deblistparser.cc') diff --git a/apt-pkg/deb/deblistparser.cc b/apt-pkg/deb/deblistparser.cc index ed5484ad9..e24ced271 100644 --- a/apt-pkg/deb/deblistparser.cc +++ b/apt-pkg/deb/deblistparser.cc @@ -357,8 +357,12 @@ unsigned short debListParser::VersionHash() continue; *J++ = tolower_ascii(*Start); - if ((*Start == '<' || *Start == '>') && Start[1] != *Start && Start[1] != '=') - *J++ = '='; + /* Normalize <= to < and >= to >. This is the wrong way around, but + * more efficient that the right way. And since we're only hashing + * it does not matter which way we normalize. */ + if ((*Start == '<' || *Start == '>') && Start[1] == '=') { + Start++; + } } Result = AddCRC16(Result,S,J - S); -- cgit v1.2.3