From 58b88779f00707b6231d827637b5a3d498f9fe28 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 11 Jan 2022 17:10:48 +0000 Subject: [PATCH] hw/intc/arm_gicv3_its: Range-check ICID before indexing into collection table MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit In process_its_cmd(), we read an ICID out of the interrupt table entry, and then use it as an index into the collection table. Add a check that it is within range for the collection table first. This check is not strictly necessary, because: * we range check the ICID from the guest before writing it into the interrupt table entry, so the the only way to get an out of range ICID in process_its_cmd() is if a badly-behaved guest is writing directly to the interrupt table memory * the collection table is in guest memory, so QEMU won't fall over if we read off the end of it However, it seems clearer to include the check. Signed-off-by: Peter Maydell Reviewed-by: Alex Bennée Message-id: 20220111171048.3545974-14-peter.maydell@linaro.org --- hw/intc/arm_gicv3_its.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/hw/intc/arm_gicv3_its.c b/hw/intc/arm_gicv3_its.c index ef6c0f55ff..b2f6a8c7f0 100644 --- a/hw/intc/arm_gicv3_its.c +++ b/hw/intc/arm_gicv3_its.c @@ -299,6 +299,13 @@ static ItsCmdResult process_its_cmd(GICv3ITSState *s, uint64_t value, return CMD_CONTINUE; } + if (icid >= s->ct.num_ids) { + qemu_log_mask(LOG_GUEST_ERROR, + "%s: invalid ICID 0x%x in ITE (table corrupted?)\n", + __func__, icid); + return CMD_CONTINUE; + } + cte_valid = get_cte(s, icid, &cte, &res); if (res != MEMTX_OK) { return CMD_STALL; -- 2.30.2