CVE-2026-98540

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

fprobe: Terminate the fgraph_data list when the reservation is not filled

fprobe_fgraph_entry() reserves shadow stack space for every fprobe with

an exit handler, but only fills it for those whose entry handler returns

0. fgraph_reserve_data() does not clear the area, so fprobe_return()

parses the unused tail as headers left over from an earlier call, and an

exit handler can run twice or despite its entry handler asking to skip

it.

Write a zero word after the last entry to terminate the walk. A zeroed

slot does not decode to a NULL fprobe on the arches that encode the

header into one unsigned long, since arch_decode_fprobe_header_fp() ORs

in FPROBE_HEADER_MSB_PATTERN, so make read_fprobe_header() return NULL

for a zeroed slot.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References