diff options
| -rw-r--r-- | apt-pkg/deb/debfile.cc | 15 | ||||
| -rwxr-xr-x | test/integration/test-cve-2020-27350 | 3 | ||||
| -rw-r--r-- | test/interactive-helper/createdeb-cve-2020-27350.cc | 4 |
3 files changed, 22 insertions, 0 deletions
diff --git a/apt-pkg/deb/debfile.cc b/apt-pkg/deb/debfile.cc index f8d752e7f..bef0cd0d8 100644 --- a/apt-pkg/deb/debfile.cc +++ b/apt-pkg/deb/debfile.cc @@ -184,11 +184,23 @@ bool debDebFile::ControlExtract::DoItem(Item &Itm,int &Fd) // --------------------------------------------------------------------- /* This sets up to extract the control block member file into a memory block of just the right size. All other files go into the bit bucket. */ + +// Upper size limit for control files. Two reasons for having a limit here: +// +// 1. We read those files into memory and want to avoid being killed by OOM +// +// 2. We allocate (Itm.Size+2)-large arrays, so this can overflow if Itm.Size +// becomes 2**64-2 or larger. This is obviously +// +// 64 MiB seems like a terribly large size that everyone should be happy with. +static const unsigned long long DEB_CONTROL_SIZE_LIMIT = 64 * 1024 * 1024; bool debDebFile::MemControlExtract::DoItem(Item &Itm,int &Fd) { // At the control file, allocate buffer memory. if (Member == Itm.Name) { + if (Itm.Size > DEB_CONTROL_SIZE_LIMIT) + return _error->Error("Control file too large: %llu > %llu bytes", Itm.Size, DEB_CONTROL_SIZE_LIMIT); delete [] Control; Control = new char[Itm.Size+2]; IsControl = true; @@ -237,6 +249,9 @@ bool debDebFile::MemControlExtract::Read(debDebFile &Deb) record. */ bool debDebFile::MemControlExtract::TakeControl(const void *Data,unsigned long long Size) { + if (Size > DEB_CONTROL_SIZE_LIMIT) + return _error->Error("Control file too large: %llu > %llu bytes", Size, DEB_CONTROL_SIZE_LIMIT); + delete [] Control; Control = new char[Size+2]; Length = Size; diff --git a/test/integration/test-cve-2020-27350 b/test/integration/test-cve-2020-27350 index 336dc5b7e..f4bb79bcb 100755 --- a/test/integration/test-cve-2020-27350 +++ b/test/integration/test-cve-2020-27350 @@ -17,3 +17,6 @@ testequal "E: Long name to large: 67108865 bytes > 1048576 bytes" runapt ${APTTE ${APTTESTHELPERSBINDIR}/createdeb-cve-2020-27350 long-link long-link.deb testequal "E: Long name to large: 67108865 bytes > 1048576 bytes" runapt ${APTTESTHELPERSBINDIR}/extract-control long-link.deb control + +${APTTESTHELPERSBINDIR}/createdeb-cve-2020-27350 long-control long-control.deb +testequal "E: Control file too large: 67108865 > 67108864 bytes" runapt ${APTTESTHELPERSBINDIR}/extract-control long-control.deb control diff --git a/test/interactive-helper/createdeb-cve-2020-27350.cc b/test/interactive-helper/createdeb-cve-2020-27350.cc index 7c58eb9df..af049d4e8 100644 --- a/test/interactive-helper/createdeb-cve-2020-27350.cc +++ b/test/interactive-helper/createdeb-cve-2020-27350.cc @@ -303,6 +303,10 @@ int main(int argc, char *argv[]) { createdeb_bigtarfilelength(fd, 'K'); } + else if (strcmp(mode, "long-control") == 0) + { + createdeb_bigtarfilelength(fd, '0'); + } else if (strcmp(mode, "test") == 0) { createdeb_test(fd); |