thunderbolt: property: Cap recursion depth in __tb_property_parse_dir()
Summary
| CVE | CVE-2026-63891 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-19 16:17:06 UTC |
| Updated | 2026-07-19 16:17:06 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: thunderbolt: property: Cap recursion depth in __tb_property_parse_dir() A DIRECTORY entry's value field is used as the dir_offset for a recursive call into __tb_property_parse_dir() with no depth counter. A crafted peer that chains DIRECTORY entries into a back-reference loop drives the parser until the kernel stack is exhausted and the guard page fires. Any untrusted XDomain peer (cable, dock, in-line inspector, adjacent host) that reaches the PROPERTIES_REQUEST control-plane exchange can trigger this without authentication. Thread a depth counter through tb_property_parse() and __tb_property_parse_dir(), and reject blocks that exceed TB_PROPERTY_MAX_DEPTH = 8. That is comfortably larger than any observed legitimate XDomain layout. Operators who do not need XDomain host-to-host discovery can disable the path entirely with thunderbolt.xdomain=0 on the kernel command line. |
Risk And Classification
EPSS: 0.002630000 probability, percentile 0.179640000 (date 2026-07-20)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 2b5f47a710172c962ef42d1b732b04d2ad0dce21 git | Not specified |
| CNA | Linux | Linux | affected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 95839a67ea56ca35732aad7f711404a3127cfe2d git | Not specified |
| CNA | Linux | Linux | affected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 0a84ab9271936c11e84e511bb52fc5682f8b6726 git | Not specified |
| CNA | Linux | Linux | affected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 b4621e5ef63405c317a84b711faf3bd75b3c6a94 git | Not specified |
| CNA | Linux | Linux | affected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 f31c6d220f455b5af63590302b30e1b932d14599 git | Not specified |
| CNA | Linux | Linux | affected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 830c8a9b467e7d3a158483d37fa7dc13892b293a git | Not specified |
| CNA | Linux | Linux | affected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 ed9455ef4bd9babc90f92e526abe3fb68c1a8709 git | Not specified |
| CNA | Linux | Linux | affected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 928abe19fbf0127003abcb1ea69cabc1c897d0ab git | Not specified |
| CNA | Linux | Linux | affected 4.15 | Not specified |
| CNA | Linux | Linux | unaffected 4.15 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.259 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.210 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.176 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.143 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.93 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.35 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0.12 7.0.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/b4621e5ef63405c317a84b711faf3bd75b3c6a94 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/ed9455ef4bd9babc90f92e526abe3fb68c1a8709 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/928abe19fbf0127003abcb1ea69cabc1c897d0ab | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/0a84ab9271936c11e84e511bb52fc5682f8b6726 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/f31c6d220f455b5af63590302b30e1b932d14599 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/2b5f47a710172c962ef42d1b732b04d2ad0dce21 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/830c8a9b467e7d3a158483d37fa7dc13892b293a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/95839a67ea56ca35732aad7f711404a3127cfe2d | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.