x86/fred: Correct speculative safety in fred_extint()
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.1%
exploitation probability
0.1%top 97% of all CVEs
observed exploitation
nono source reports it
In the Linux kernel, the following vulnerability has been resolved:
x86/fred: Correct speculative safety in fred_extint()
array_index_nospec() is no use if the result gets spilled to the stack, as
it makes the believed safe-under-speculation value subject to memory
predictions.
For all practical purposes, this means array_index_nospec() must be used in
the expression that accesses the array.
As the code currently stands, it's the wrong side of irqentry_enter(), and
'index' is put into %ebp across the function call.
Remove the index variable and reposition array_index_nospec(), so it's
calculated immediately before the array access.
Affected products
Linux · Linux