CVE-2026-97980

In the Linux kernel, the following vulnerability has been resolved: s390/debug: Fix NULL pointer dereference in debug_set_level() Commit a2cec6863709 ("s390/debug: Add s390dbf kernel parameter") incorrectly removed a null-id check from debug_set_level(), introducing a possible NULL pointer dereference for debug-API users that put debug_register() results unchecked into debug_set_level(). Fix this by moving the check from the internal _debug_set_level() variant back to the external debug_set_level() wrapper.

• https://git.kernel.org/stable/c/716e1cd3783806929407dbd596e6b1118971eb9e
• https://git.kernel.org/stable/c/b1eb31d533cdfcae1011ed53850d52f36afe5774