CVE-2021-47284

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 5.13.0-rc1-00144-g25a1298726e #13

Description A vulnerability in the Linux kernel has been resolved, specifically in the isdn: mISDN: netjet module. The issue arises when 'nj setup' in netjet.c fails with -EIO, causing 'card->irq' to be initialized with a value greater than zero. A subsequent call to 'nj release' will then attempt to free the irq that was not requested, leading to a crash. The KASAN log reveals this issue. The vulnerability is related to the use of the free irq function and the nj release function.

Recommendations To resolve this issue, update the Linux kernel to a version that includes the fix for this vulnerability. Specifically, the fix involves deleting the previous assignment to 'card->irq' and keeping only the assignment before 'request irq'. As a temporary workaround, consider disabling the nj setup function in netjet.c until a patch is available.