In the Linux kernel, the following vulnerability has been resolved:
powerpc/rtas: Prevent Spectre v1 gadget construction in sys_rtas()
Smatch warns:
arch/powerpc/kernel/rtas.c:1932 __do_sys_rtas() warn: potential spectre issue 'args.args' [r] (local cap)
The 'nargs' and 'nret' locals come directly from a user-supplied buffer and are used as indexes into a small stack-based array and as inputs to copy_to_user() after they are subject to bounds checks.
Use array_index_nospec() after the bounds checks to clamp these values for speculative execution.
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:NI:HA:H7.1/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H