FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

FreeBSD -- System call kernel data register leak

Affected packages
12.0	<=	FreeBSD-kernel	<	12.0_3
11.2	<=	FreeBSD-kernel	<	11.2_9

Details

VuXML ID	683c714d-2d91-11e9-bf3e-a4badb2f4699
Discovery	2019-02-05
Entry	2019-02-11

Problem Description:

The callee-save registers are used by kernel and for some of them (%r8, %r10, and for non-PTI configurations, %r9) the content is not sanitized before return from syscalls, potentially leaking sensitive information.

Impact:

Typically an address of some kernel data structure used in the syscall implementation, is exposed.

References

CVE Name	CVE-2019-5595
FreeBSD Advisory	SA-19:01.syscall