Bug 2555178 (CVE-2026-98687)
| Summary: | CVE-2026-98687 kernel: thunderbolt: Reject oversized XDomain properties responses | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the Linux kernel's Thunderbolt driver. When processing property requests from peer devices, the driver fails to verify that the response data length does not exceed the allocated buffer size. A malicious peer can exploit this flaw by sending an oversized response packet, triggering an out-of-bounds read from heap memory. This issue may allow an attacker to disclose sensitive kernel memory or cause a Denial of Service (DoS) by crashing the system.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
In the Linux kernel, the following vulnerability has been resolved: thunderbolt: Reject oversized XDomain properties responses tb_xdp_properties_request() allocates room for 45 data dwords in its 252-byte response buffer. The XDomain length field is six bits wide, however, and a malicious peer can set it to 63. After the fixed response fields are subtracted, the driver treats this as 48 data dwords. Commit 322e93448d90 ("thunderbolt: Clamp XDomain response data copy to allocation size") only bounds the copy against data_len. If data_len is at least 48, memcpy() reads 192 bytes from the 180-byte res->data array, causing a 12-byte heap out-of-bounds read. Commit 4db2bd2ed478 ("thunderbolt: Limit XDomain response copy to actual frame size") limits the earlier copy but does not constrain this header-derived length. Reject response data lengths that exceed the allocated source buffer before copying them into the assembled property block.