CVE-2026-63891

thunderbolt: property: Cap recursion depth in __tb_property_parse_dir()

State: Published
Severity: Not scored
Published: Jul 19, 2026
Updated: Jul 19, 2026
Reserved: Jul 19, 2026

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.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before 2b5f47a710172c962ef42d1b732b04d2ad0dce21Affected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before 95839a67ea56ca35732aad7f711404a3127cfe2dAffected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before 0a84ab9271936c11e84e511bb52fc5682f8b6726Affected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before b4621e5ef63405c317a84b711faf3bd75b3c6a94Affected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before f31c6d220f455b5af63590302b30e1b932d14599Affected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before 830c8a9b467e7d3a158483d37fa7dc13892b293aAffected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before ed9455ef4bd9babc90f92e526abe3fb68c1a8709Affected cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before 928abe19fbf0127003abcb1ea69cabc1c897d0abAffected
LinuxLinux	4.15Affected before 4.15Not affected 5.10.259 through 5.10.Not affected 5.15.210 through 5.15.Not affected 6.1.176 through 6.1.Not affected 6.6.143 through 6.6.Not affected 6.12.93 through 6.12.Not affected 6.18.35 through 6.18.Not affected 7.0.12 through 7.0.*Not affected 7.1 and laterNot affected

Product

Versions

LinuxLinux

cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before 2b5f47a710172c962ef42d1b732b04d2ad0dce21Affected
cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before 95839a67ea56ca35732aad7f711404a3127cfe2dAffected
cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before 0a84ab9271936c11e84e511bb52fc5682f8b6726Affected
cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before b4621e5ef63405c317a84b711faf3bd75b3c6a94Affected
cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before f31c6d220f455b5af63590302b30e1b932d14599Affected
cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before 830c8a9b467e7d3a158483d37fa7dc13892b293aAffected
cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before ed9455ef4bd9babc90f92e526abe3fb68c1a8709Affected
cdae7c07e3e3509eaabc18c1640a55dc5b99c179 to before 928abe19fbf0127003abcb1ea69cabc1c897d0abAffected

LinuxLinux

4.15Affected
before 4.15Not affected
5.10.259 through 5.10.*Not affected
5.15.210 through 5.15.*Not affected
6.1.176 through 6.1.*Not affected
6.6.143 through 6.6.*Not affected
6.12.93 through 6.12.*Not affected
6.18.35 through 6.18.*Not affected
7.0.12 through 7.0.*Not affected
7.1 and laterNot affected

References

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