Control: tags -1 upstream patch (Copy of message sent to the author of nzbget) Hi there,
Debian (and Ubuntu) use hardening flags to harden their binaries against memory corruption attacks and get some useful warning messages during compiles. One such warning, when building with -D_FORTIFY_SOURCE=2 [1] is this: > $ g++ -D_FORTIFY_SOURCE=2 -g -O2 -c -o RemoteClient.o RemoteClient.cpp > In file included from /usr/include/string.h:638:0, > from RemoteClient.cpp:36: > In function char* strncat(char*, const char*, size_t), > inlined from bool RemoteClient::RequestServerList(bool, bool, const > char*) at RemoteClient.cpp:537:59: > /usr/include/x86_64-linux-gnu/bits/string3.h:150:71: warning: call to char* > __builtin___strncat_chk(char*, const char*, long unsigned int, long unsigned > int) might overflow destination buffer [enabled by default] > return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest)); > ^ > In function char* strncat(char*, const char*, size_t), > inlined from bool RemoteClient::RequestServerList(bool, bool, const > char*) at RemoteClient.cpp:539:60: > /usr/include/x86_64-linux-gnu/bits/string3.h:150:71: warning: call to char* > __builtin___strncat_chk(char*, const char*, long unsigned int, long unsigned > int) might overflow destination buffer [enabled by default] > return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest)); > ^ > In function char* strncat(char*, const char*, size_t), > inlined from bool RemoteClient::RequestServerList(bool, bool, const > char*) at RemoteClient.cpp:661:117: > /usr/include/x86_64-linux-gnu/bits/string3.h:150:71: warning: call to char* > __builtin___strncat_chk(char*, const char*, long unsigned int, long unsigned > int) might overflow destination buffer [enabled by default] > return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest)); > ^ My proposal to fix this is to use > strncat(szParameters, pNZBParameter->GetName(), > sizeof(szParameters)-strlen(szParameters)-1); instead of > strncat(szParameters, pNZBParameter->GetName(), 1024); I've attached a patch with those changes. Do you think that this is ok? Cheers, Andreas [1] https://wiki.debian.org/Hardening#gcc_-D_FORTIFY_SOURCE.3D2_-O1
--- RemoteClient.cpp.orig 2013-08-21 17:53:33.000000000 +0000
+++ RemoteClient.cpp 2013-08-21 17:48:38.000000000 +0000
@@ -534,9 +534,9 @@
strncat(szParameters, ", ", 1024);
}
NZBParameter* pNZBParameter = *it;
- strncat(szParameters, pNZBParameter->GetName(), 1024);
- strncat(szParameters, "=", 1024);
- strncat(szParameters, pNZBParameter->GetValue(), 1024);
+ strncat(szParameters, pNZBParameter->GetName(), sizeof(szParameters)-strlen(szParameters)-1);
+ strncat(szParameters, "=", sizeof(szParameters)-strlen(szParameters)-1);
+ strncat(szParameters, pNZBParameter->GetValue(), sizeof(szParameters)-strlen(szParameters)-1);
}
if (szParameters[0] != '\0')
{
@@ -658,7 +658,7 @@
if (ntohl(ListResponse.m_iPostJobCount) > 0 || ntohl(ListResponse.m_bPostPaused))
{
- strncat(szServerState, strlen(szServerState) > 0 ? ", Post-Processing" : "Post-Processing", sizeof(szServerState));
+ strncat(szServerState, strlen(szServerState) > 0 ? ", Post-Processing" : "Post-Processing", sizeof(szServerState)-strlen(szServerState)-1);
if (ntohl(ListResponse.m_bPostPaused))
{
strncat(szServerState, " paused", sizeof(szServerState));
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