3.16.84-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Marios Pomonis <[email protected]> commit 8c86405f606ca8508b8d9280680166ca26723695 upstream. This fixes a Spectre-v1/L1TF vulnerability in ioapic_read_indirect(). This function contains index computations based on the (attacker-controlled) IOREGSEL register. Fixes: a2c118bfab8b ("KVM: Fix bounds checking in ioapic indirect register reads (CVE-2013-1798)") Signed-off-by: Nick Finco <[email protected]> Signed-off-by: Marios Pomonis <[email protected]> Reviewed-by: Andrew Honig <[email protected]> Reviewed-by: Jim Mattson <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <[email protected]> --- virt/kvm/ioapic.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -36,6 +36,7 @@ #include <linux/io.h> #include <linux/slab.h> #include <linux/export.h> +#include <linux/nospec.h> #include <asm/processor.h> #include <asm/page.h> #include <asm/current.h> @@ -73,13 +74,14 @@ static unsigned long ioapic_read_indirec default: { u32 redir_index = (ioapic->ioregsel - 0x10) >> 1; - u64 redir_content; + u64 redir_content = ~0ULL; - if (redir_index < IOAPIC_NUM_PINS) - redir_content = - ioapic->redirtbl[redir_index].bits; - else - redir_content = ~0ULL; + if (redir_index < IOAPIC_NUM_PINS) { + u32 index = array_index_nospec( + redir_index, IOAPIC_NUM_PINS); + + redir_content = ioapic->redirtbl[index].bits; + } result = (ioapic->ioregsel & 0x1) ? (redir_content >> 32) & 0xffffffff :
