UBUNTU-CVE-2026-99219: Medium severity ubuntu/linux vulnerability
In the Linux kernel, the following vulnerability has been resolved: ftrace: Initialize modname and offset in printrec() printrec() leaves 'modname' and 'offset' uninitialized and kallsymslookup() only sets them on success. When the lookup fails like when a module is being loaded or unloaded, 'modname' holds a garbage value, passes the 'if (modname)' check, and is dereferenced by seqprintf(). Oops: general protection fault RIP: 0010:string+0x48/0xe0 Call Trace: vsnprintf+0x1f5/0x650 seqprintf+0x8e/0xb0 printrec+0x6c/0xc0 tshow+0x4c/0x440 seqreaditer+0x119/0x480 This can be triggered by reading availablefilterfunctions while a module is being loaded or unloaded. Initialize both variables so a failed lookup skips the module name.
Affected Software
Event History
Frequently Asked Questions
What circumstances are required to trigger this issue?
The issue can be triggered by reading available_filter_functions while a kernel module is being loaded or unloaded. In that timing window, kallsyms_lookup() can fail and leave data used by print_rec() uninitialized.
What is the likely impact if the issue is triggered?
The kernel can dereference a garbage module-name pointer during seq_printf(), causing a general protection fault and an oops. The provided call trace indicates this is a kernel crash condition.
Which Ubuntu kernel packages are identified as affected?
The listed packages are ubuntu/linux, ubuntu/linux-fips, ubuntu/linux-aws, ubuntu/linux-azure, ubuntu/linux-gcp, ubuntu/linux-oracle, ubuntu/linux-aws-fips, and ubuntu/linux-azure-fips.