Fix NULL pointer dereference in logcollector when no logfiles configured#2168
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atomicturtle merged 2 commits intoossec:mainfrom Jan 23, 2026
Merged
Fix NULL pointer dereference in logcollector when no logfiles configured#2168atomicturtle merged 2 commits intoossec:mainfrom
atomicturtle merged 2 commits intoossec:mainfrom
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When all logfile tags are removed from ossec.conf, logcollector would segfault due to a NULL pointer dereference on line 292. The code was calling strncmp() on logff[i].logformat without checking if it was NULL. This fix adds a NULL check before the strncmp() call to prevent the segfault when no logfiles are configured. Fixes segfault reported on Ubuntu 22.04 (Jammy) with version 3.8.0.
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Pull request overview
Fixes a logcollector crash when no <localfile> entries are configured by preventing a NULL dereference during journald/command handling.
Changes:
- Add a NULL check before calling
strncmp()onlogff[i].logformatinside the main loop.
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Based on code review feedback, the previous fix didn't handle the case where logformat is 'journald' but the binary is built without HAVE_SYSTEMD. In that case, logff[i].read is not set, and calling it later would crash. The improved fix checks if logff[i].read is set before attempting to call it, which handles both: - NULL logformat when no logfiles are configured - journald entries when built without HAVE_SYSTEMD support This is a more robust solution that prevents crashes in both scenarios.
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Pull request overview
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When all logfile tags are removed from ossec.conf, logcollector would segfault due to a NULL pointer dereference on line 292. The code was calling strncmp() on logff[i].logformat without checking if it was NULL.
This fix adds a NULL check before the strncmp() call to prevent the segfault when no logfiles are configured.
Fixes segfault reported on Ubuntu 22.04 (Jammy) with version 3.8.0. Closes issue #2156