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Bug 1037297 - qt3 FTBFS if "-Werror=format-security" flag is used
Summary: qt3 FTBFS if "-Werror=format-security" flag is used
Keywords:
Status: CLOSED RAWHIDE
Alias: None
Product: Fedora
Classification: Fedora
Component: qt3
Version: rawhide
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Than Ngo
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks: 1038083
TreeView+ depends on / blocked
 
Reported: 2013-12-03 05:54 UTC by Dhiru Kholia
Modified: 2014-03-25 03:45 UTC (History)
4 users (show)

Fixed In Version: qt3-3.3.8b-56.fc21
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2014-01-14 03:53:13 UTC
Type: ---
Embargoed:

Attachments (Terms of Use)

Description Dhiru Kholia 2013-12-03 05:54:27 UTC 
Description of problem
----------------------

qt3 fails to build if "-Werror=format-security" flag is used.

...

../tools/qgdict.cpp:849:26: error: format not a string literal and no format arguments [-Werror=format-security]
../tools/qgdict.cpp:853:23: error: format not a string literal and no format arguments [-Werror=format-security]
../tools/qgdict.cpp:874:14: error: format not a string literal and no format arguments [-Werror=format-security]
../tools/qgdict.cpp:882:26: error: format not a string literal and no format arguments [-Werror=format-security]

...

We are working on a proposal to enable "-Werror=format-security" for all
packages. Once this flag is enabled, GCC will refuse to compile code that could
be vulnerable to a string format security flaw. For more details, please see
https://fedorahosted.org/fesco/ticket/1185 page.

To understand why it is important to fix this, please see
https://fedoraproject.org/wiki/Format-Security-FAQ page.

How to fix this
---------------

The fix for these errors is quite simple. It's a matter of changing a
line like,

   printf(foo);

to read,

   printf("%s", foo);

That's it.

Please fix this issue in rawhide with a patch (which you should submit
to upstream to merge moving forward). Please do a new build with the
fix in rawhide. Other releases do not need to be directly fixed, but
there should be no harm in pushing out this fix/patch with other needed
changes to those branches.

In the event you don't fix this bug before the next mass rebuild,
provenpackagers may step in and update your package(s) to fix this
issue.

How reproducible
----------------

Build qt3-3.3.8b-53.fc21.src.rpm with "-Werror=format-security" flag to reproduce the problem.

To make this process easier, you can use a modified "redhat-rpm-config" package
from http://people.fedoraproject.org/~halfie/artifacts/redhat-rpm-config/ URL.

$ sha256sum redhat-rpm-config-9.1.0-56.fc20.*
faad7594b2080fe76497d0ce50808c905a93dd7b41c1defdde5ca57e3833d3d2  redhat-rpm-config-9.1.0-56.fc20.noarch.rpm
5aa9357174305c7285ffdbc92d7ffe1c07a8a95d5459b930461308f5aad75413  redhat-rpm-config-9.1.0-56.fc20.src.rpm
Comment 1 Kevin Kofler 2014-01-14 03:53:13 UTC 
As I pointed out to FESCo, the 4 errors above are all false positives, "line.ascii()" contains only '-' characters, "buf" contains only '*' characters. But that's only the first file that fails, there are 4 more:
* qgcache.cpp: also trivially false positives as above.
* moc.y / moc_yacc.cpp: false positives, constant format strings in const char * variables.
* qjpegio.cpp: This one may or may not be a problem depending on what libjpeg's format_message can return. That's the only one I'm unsure about. It's fixed now ("%s" added) in any case.
* qsql_odbc.cpp: Arguably a bug, if a client program is really dumb enough to pass junk that may contain '%' characters where constant strings such as "SQL_MODE_READ_ONLY" are expected. Otherwise, false positives. I strongly doubt any client program makes this exploitable.

This is the whole mess I had to commit to make the broken warning/error happy:
http://pkgs.fedoraproject.org/cgit/qt3.git/tree/qt-x11-free-3.3.8b-%231037297.patch

It took me about 2 hours to clean up this mess!
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