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When running libnss-cache behind nscd, this author observed a large number of fd leaks that corresponded to cache files. In the scenario in which the leaks occurred, the leaked fds prevented old deleted cache files from getting freed on disk, and resulted in the root volume filling up. An audit of the nss_cache module found multiple paths where it was possible to leak a FILE pointer that would in turn result in a fd being leaked. After applying this fix, none of the leaks reoccurred, even after 24+ hours of testing.
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When running libnss-cache behind nscd, this author observed fd leaks that corresponded to cache files. In the scenario in which the leaks occurred, the leaked fds prevented old deleted cache files from getting freed on disk, and resulted in the root volume filling up.
An audit of the nss_cache module found multiple paths where it was possible to leak a FILE pointer that would in turn result in a fd being leaked. After applying this fix, none of the leaks reoccurred, even after 24+ hours of testing.
For the changes outside of
_nss_cache_bsearch2, the fix mimics the behavior in the internal glibc functions. E.g. if the FILE pointer is NULL, open the file. Otherwise, rewind the FILE.