Bug 2213139 (CVE-2023-31084)

Summary: CVE-2023-31084 kernel: blocking operation in dvb_frontend_get_event and wait_event_interruptible
Product: [Other] Security Response Reporter: Alex <allarkin>
Component: vulnerabilityAssignee: Nobody <nobody>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: acaringi, allarkin, bhu, chwhite, dbohanno, ddepaula, debarbos, dfreiber, dnelson, dvlasenk, ezulian, hkrzesin, jarod, jburrell, jdenham, jfaracco, jferlan, jforbes, jlelli, joe.lawrence, jshortt, jstancek, jwyatt, kcarcia, kernel-mgr, ldoskova, lgoncalv, lleshchi, lzampier, nmurray, ptalbert, qzhao, rogbas, rrobaina, rvrbovsk, rysulliv, scweaver, stanley.king, swood, tyberry, vkumar, walters, wcosta, williams, wmealing, ycote
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A potential deadlock flaw was found in the Linux’s kernel DVB API (used by Digital TV devices) functionality. This flaw allows a local user to crash the system.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2213141, 2213142, 2213140, 2213143, 2213144    
Bug Blocks: 2189448    

Description Alex 2023-06-07 08:25:28 UTC 
A flaw in the Linux Kernel found in drivers/media/dvb-core/dvb_frontend.c. There is a blocking operation when a task is in !TASK_RUNNING. In dvb_frontend_get_event, wait_event_interruptible is called; the condition is dvb_frontend_test_event(fepriv,events). In dvb_frontend_test_event, down(&fepriv->sem) is called. However, wait_event_interruptible would put the process to sleep, and down(&fepriv->sem) may block the process.

Reference:
https://lore.kernel.org/all/CA+UBctCu7fXn4q41O_3=id1+OdyQ85tZY1x+TkT-6OVBL6KAUw@mail.gmail.com/
Comment 1 Alex 2023-06-07 08:25:54 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2213140]