CVE-2026-80679: s390/dasd: Fix potential NULL pointer dereference
In the Linux kernel, the following vulnerability has been resolved:
s390/dasd: Fix potential NULL pointer dereference
dasdreleasespace() checks the implementation of the isese() discipline function before calling it to determine if a given device is an ESE DASD.
The current usage of the logical AND operator will lead to a NULL pointer dereference as the function is called even if the function pointer is NULL.
Fix this by using the logical OR operator.
Affected Software
Event History
Frequently Asked Questions
Which systems are in scope for this issue?
The issue is in the Linux kernel s390 DASD code. Systems not using the s390 DASD subsystem are not indicated by the provided information as being affected.
What condition is needed to trigger the NULL pointer dereference?
dasd_release_space() must handle a DASD discipline whose is_ese() function implementation is NULL. The flawed logical-AND check calls the function even when that function pointer is NULL.
How is the issue corrected?
The resolved fix changes the condition to use a logical OR operator, preventing is_ese() from being called when its implementation is NULL. The provided stable kernel references identify commits containing the fix, but no affected or fixed kernel versions are specified.