Bug 1425825
| Summary: | gcc -Werror=format-security -Wall not reporting errors | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Frantisek Kluknavsky <fkluknav> |
| Component: | gcc | Assignee: | Jakub Jelinek <jakub> |
| Status: | CLOSED RAWHIDE | QA Contact: | Fedora Extras Quality Assurance <extras-qa> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 25 | CC: | davejohansen, jakub, jwakely, law, mpolacek |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2017-03-07 19:44:46 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
Filed upstream: PR79677. In the mean time, use -Wformat-security -Werror=format-security instead of just -Werror=format-security and then it will work properly. "-Wformat-security -Werror=format-security" gives "error: -Wformat-security ignored without -Wformat" "-Wformat -Wformat-security -Werror=format-security" works. Fun note: Fedora currently uses -Wall -Werror=format-security. While it is possible to get warnings with a right combination of flags (if you know...), it is a very strange feeling to fix rpm build errors by adding another -Wall. Surprisingly satisfying ;-) Fixed in F26, not going to backport. |
Description of problem: Combination of -Wformat and -Werror=format-security flags (or -Wall and -Werror=format-security) does not behave consistently. Using 'gcc -Wformat -Werror=format-security' with the source file provided below reports error "format not a string literal and no format arguments" on line 7 as expected whereas 'gcc -Werror=format-security -Wformat' does not. Similar behavior can be observed with the -Wall flag instead of -Wformat. Version-Release number of selected component (if applicable): gcc-6.3.1-1.fc25.x86_64 How reproducible: always Steps to Reproduce: 1. $ cat formatsecurity.c #include <stdio.h> int main() { char message[10]; message[0]=0; printf(message); return 0; } 2. $ gcc -Wall -Werror=format-security formatsecurity.c 3. $ gcc -Wall -Werror=format-security -Wall formatsecurity.c 4. $ gcc -Werror=format-security -Wall formatsecurity.c Actual results: Error after step 2, silent run after steps 3 and 4. Expected results: Error message after each run of gcc. Either about vulnerable code or about wrong usage of flags. Adding -Wall should definitely not hide errors as in step 3.