Received: from eggs.gnu.org ([2001:4830:134:3::10]:34248) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eE8DB-0003EG-3S for qemu-devel@nongnu.org; Mon, 13 Nov 2017 01:27:14 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eE8DA-0006BL-0S for qemu-devel@nongnu.org; Mon, 13 Nov 2017 01:27:13 -0500 From: P J P Date: Mon, 13 Nov 2017 11:56:58 +0530 Message-Id: <20171113062658.9697-1-ppandit@redhat.com> Subject: [Qemu-devel] [PATCH v2] highbank: validate register offset before access List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Qemu Developers Cc: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Moguofang , Peter Maydell , qemu-arm@nongnu.org, Shawn Guo , Rob Herring , Prasad J Pandit From: Prasad J Pandit An 'offset' parameter sent to highbank register r/w functions could be greater than number(NUM_REGS=0x200) of hb registers, leading to an OOB access issue. Add check to avoid it. Reported-by: Moguofang (Dennis mo) Signed-off-by: Prasad J Pandit --- hw/arm/highbank.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) Update: use HWADDR_PRIx to print offset -> https://lists.gnu.org/archive/html/qemu-devel/2017-11/msg02116.html diff --git a/hw/arm/highbank.c b/hw/arm/highbank.c index 354c6b25a8..287392bbdc 100644 --- a/hw/arm/highbank.c +++ b/hw/arm/highbank.c @@ -34,6 +34,7 @@ #include "hw/ide/ahci.h" #include "hw/cpu/a9mpcore.h" #include "hw/cpu/a15mpcore.h" +#include "qemu/log.h" #define SMP_BOOT_ADDR 0x100 #define SMP_BOOT_REG 0x40 @@ -117,14 +118,26 @@ static void hb_regs_write(void *opaque, hwaddr offset, } } - regs[offset/4] = value; + if (offset / 4 >= NUM_REGS) { + qemu_log_mask(LOG_GUEST_ERROR, + "highbank: bad write offset 0x%" HWADDR_PRIx "\n", offset); + return; + } + regs[offset / 4] = value; } static uint64_t hb_regs_read(void *opaque, hwaddr offset, unsigned size) { + uint32_t value; uint32_t *regs = opaque; - uint32_t value = regs[offset/4]; + + if (offset / 4 >= NUM_REGS) { + qemu_log_mask(LOG_GUEST_ERROR, + "highbank: bad read offset 0x%" HWADDR_PRIx "\n", offset); + return 0; + } + value = regs[offset / 4]; if ((offset == 0x100) || (offset == 0x108) || (offset == 0x10C)) { value |= 0x30000000; -- 2.13.6