Bug 26697 - NULL pointer dereference might happen in get_utrace_lock()
Summary: NULL pointer dereference might happen in get_utrace_lock()
Status: RESOLVED FIXED
Alias: None
Product: systemtap
Classification: Unclassified
Component: runtime (show other bugs)
Version: unspecified
: P2 normal
Target Milestone: ---
Assignee: Unassigned
URL:
Keywords:
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Blocks:
 
Reported: 2020-10-01 22:24 UTC by agentzh
Modified: 2020-10-01 22:29 UTC (History)
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Description agentzh 2020-10-01 22:24:41 UTC 
We often observed kernel panics like the following when fuzzing systemtap with load:

```
BUG: unable to handle kernel NULL pointer dereference at           (null)
 #9 [ffff8843e56ffd20] get_utrace_lock at ffffffffc08258c6 [stap_X_40544]
```

Investigating the kdump reveals that the NULL pointer is returned by the task_utrace_struct() function.
Comment 1 agentzh 2020-10-01 22:29:15 UTC 
Fixed in commit 619f6940d. Thanks Sultan Alsawaf for the patch.