do_config_file() should exit with an error code on internal run-time errors, and not return if it fails as then the error in do_config_file() would go unnoticed in the current code and allow the build to continue. The exit with error code will make the build fail in those very exceptional cases. If this occurs, this actually indicates a deeper problem in the execution of the kernel build process. Now, in these error cases, we do not explicitly free memory and close the file handlers in do_config_file(), as this is covered by exit(). This issue in the fixdep script was introduced with its initial implementation back in 2002 by the original author Kai Germaschewski with this commit 04bd72170653 ("kbuild: Make dependencies at compile time") in the linux history git tree, i.e., git://git.kernel.org/pub/scm/linux/kernel/git/history/history.git. This issue was identified during the review of a previous patch that intended to address a memory leak detected by a static analysis tool. Link: https://lkml.org/lkml/2017/12/14/736
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| @@ -290,13 +290,11 @@ static void do_config_file(const char *filename) · 289 unmodified lines | ||
| 290 | 290 | map = malloc(st.st_size + 1); |
| 291 | 291 | if (!map) { |
| 292 | 292 | perror("fixdep: malloc"); |
| 293 | − close(fd); | |
| 294 | − return; | |
| 293 | + exit(2); | |
| 295 | 294 | } |
| 296 | 295 | if (read(fd, map, st.st_size) != st.st_size) { |
| 297 | 296 | perror("fixdep: read"); |
| 298 | − close(fd); | |
| 299 | − return; | |
| 297 | + exit(2); | |
| 300 | 298 | } |
| 301 | 299 | map[st.st_size] = '\0'; |
| 302 | 300 | close(fd); |