From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757295AbdJKJmy (ORCPT ); Wed, 11 Oct 2017 05:42:54 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:57312 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751964AbdJKJmv (ORCPT ); Wed, 11 Oct 2017 05:42:51 -0400 From: Punit Agrawal To: linux-kernel@vger.kernel.org Cc: Punit Agrawal , marc.zyngier@arm.com, linux-arm-kernel@lists.infradead.org Subject: [PATCH 3/3] irqchip/gic-v3: Bounds check redistributor accesses Date: Wed, 11 Oct 2017 10:41:48 +0100 Message-Id: <20171011094148.15674-4-punit.agrawal@arm.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20171011094148.15674-1-punit.agrawal@arm.com> References: <20171011094148.15674-1-punit.agrawal@arm.com> X-ARM-No-Footer: FoSSMail Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The kernel crashes while iterating over a redistributor that is in-correctly sized by the platform firmware or doesn't contain the last record. Prevent the crash by checking accesses against the size of the region provided by the firmware. While we are at it, warn the user about incorrect region size. Signed-off-by: Punit Agrawal Cc: Marc Zyngier --- drivers/irqchip/irq-gic-v3.c | 48 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 40 insertions(+), 8 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 881d327c53fa..754d936c95e5 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -429,11 +429,21 @@ static int gic_iterate_rdists(int (*fn)(struct redist_region *, void __iomem *)) int i; for (i = 0; i < gic_data.nr_redist_regions; i++) { - void __iomem *ptr = gic_data.redist_regions[i].redist_base; struct resource *res = &gic_data.redist_regions[i].res; - u64 typer; + void __iomem *ptr, *base; + u64 typer, size, stride; u32 reg; + ptr = base = gic_data.redist_regions[i].redist_base; + size = resource_size(res); + + stride = gic_data.redist_stride ?: SZ_64K * 2; + if (ptr + stride > base + size) { + pr_warn("Insufficient size for redistributor region @%llx. Skipping\n", + res->start); + continue; + } + reg = readl_relaxed(ptr + GICR_PIDR2) & GIC_PIDR2_ARCH_MASK; if (reg != GIC_PIDR2_ARCH_GICv3 && reg != GIC_PIDR2_ARCH_GICv4) { /* We're in trouble... */ @@ -442,7 +452,28 @@ static int gic_iterate_rdists(int (*fn)(struct redist_region *, void __iomem *)) } do { + /* + * We can access GICR_TYPER as we have already + * checked that we have atleast 128kB or + * redist_stride + */ typer = gic_read_typer(ptr + GICR_TYPER); + if (!gic_data.redist_stride && + (typer & GICR_TYPER_VLPIS)) { + /* VLPI_base + reserved page */ + stride += SZ_64K * 2; + + /* + * We are larger than we thought, do + * we still fit? + */ + if (ptr + stride > base + size) { + pr_warn("No last record found in redistributor region @%llx\n", + gic_data.redist_regions[i].res.start); + break; + } + } + ret = fn(gic_data.redist_regions + i, ptr); if (!ret) return 0; @@ -450,12 +481,13 @@ static int gic_iterate_rdists(int (*fn)(struct redist_region *, void __iomem *)) if (gic_data.redist_regions[i].single_redist) break; - if (gic_data.redist_stride) { - ptr += gic_data.redist_stride; - } else { - ptr += SZ_64K * 2; /* Skip RD_base + SGI_base */ - if (typer & GICR_TYPER_VLPIS) - ptr += SZ_64K * 2; /* Skip VLPI_base + reserved page */ + ptr += stride; + + stride = gic_data.redist_stride ?: SZ_64K * 2; + if (ptr + stride > base + size) { + pr_warn("No last record found in redistributor region @%llx\n", + gic_data.redist_regions[i].res.start); + break; } } while (!(typer & GICR_TYPER_LAST)); } -- 2.14.1 From mboxrd@z Thu Jan 1 00:00:00 1970 From: punit.agrawal@arm.com (Punit Agrawal) Date: Wed, 11 Oct 2017 10:41:48 +0100 Subject: [PATCH 3/3] irqchip/gic-v3: Bounds check redistributor accesses In-Reply-To: <20171011094148.15674-1-punit.agrawal@arm.com> References: <20171011094148.15674-1-punit.agrawal@arm.com> Message-ID: <20171011094148.15674-4-punit.agrawal@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The kernel crashes while iterating over a redistributor that is in-correctly sized by the platform firmware or doesn't contain the last record. Prevent the crash by checking accesses against the size of the region provided by the firmware. While we are at it, warn the user about incorrect region size. Signed-off-by: Punit Agrawal Cc: Marc Zyngier --- drivers/irqchip/irq-gic-v3.c | 48 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 40 insertions(+), 8 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 881d327c53fa..754d936c95e5 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -429,11 +429,21 @@ static int gic_iterate_rdists(int (*fn)(struct redist_region *, void __iomem *)) int i; for (i = 0; i < gic_data.nr_redist_regions; i++) { - void __iomem *ptr = gic_data.redist_regions[i].redist_base; struct resource *res = &gic_data.redist_regions[i].res; - u64 typer; + void __iomem *ptr, *base; + u64 typer, size, stride; u32 reg; + ptr = base = gic_data.redist_regions[i].redist_base; + size = resource_size(res); + + stride = gic_data.redist_stride ?: SZ_64K * 2; + if (ptr + stride > base + size) { + pr_warn("Insufficient size for redistributor region @%llx. Skipping\n", + res->start); + continue; + } + reg = readl_relaxed(ptr + GICR_PIDR2) & GIC_PIDR2_ARCH_MASK; if (reg != GIC_PIDR2_ARCH_GICv3 && reg != GIC_PIDR2_ARCH_GICv4) { /* We're in trouble... */ @@ -442,7 +452,28 @@ static int gic_iterate_rdists(int (*fn)(struct redist_region *, void __iomem *)) } do { + /* + * We can access GICR_TYPER as we have already + * checked that we have atleast 128kB or + * redist_stride + */ typer = gic_read_typer(ptr + GICR_TYPER); + if (!gic_data.redist_stride && + (typer & GICR_TYPER_VLPIS)) { + /* VLPI_base + reserved page */ + stride += SZ_64K * 2; + + /* + * We are larger than we thought, do + * we still fit? + */ + if (ptr + stride > base + size) { + pr_warn("No last record found in redistributor region @%llx\n", + gic_data.redist_regions[i].res.start); + break; + } + } + ret = fn(gic_data.redist_regions + i, ptr); if (!ret) return 0; @@ -450,12 +481,13 @@ static int gic_iterate_rdists(int (*fn)(struct redist_region *, void __iomem *)) if (gic_data.redist_regions[i].single_redist) break; - if (gic_data.redist_stride) { - ptr += gic_data.redist_stride; - } else { - ptr += SZ_64K * 2; /* Skip RD_base + SGI_base */ - if (typer & GICR_TYPER_VLPIS) - ptr += SZ_64K * 2; /* Skip VLPI_base + reserved page */ + ptr += stride; + + stride = gic_data.redist_stride ?: SZ_64K * 2; + if (ptr + stride > base + size) { + pr_warn("No last record found in redistributor region @%llx\n", + gic_data.redist_regions[i].res.start); + break; } } while (!(typer & GICR_TYPER_LAST)); } -- 2.14.1