From: Punit Agrawal <punit.agrawal@arm.com> To: linux-kernel@vger.kernel.org Cc: Punit Agrawal <punit.agrawal@arm.com>, 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 [thread overview] Message-ID: <20171011094148.15674-4-punit.agrawal@arm.com> (raw) In-Reply-To: <20171011094148.15674-1-punit.agrawal@arm.com> 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 <punit.agrawal@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> --- 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
WARNING: multiple messages have this Message-ID (diff)
From: punit.agrawal@arm.com (Punit Agrawal) To: 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 [thread overview] Message-ID: <20171011094148.15674-4-punit.agrawal@arm.com> (raw) In-Reply-To: <20171011094148.15674-1-punit.agrawal@arm.com> 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 <punit.agrawal@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> --- 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
next prev parent reply other threads:[~2017-10-11 9:42 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-10-11 9:41 [PATCH 0/3] GICv3: Bounds check redistributor accesses Punit Agrawal 2017-10-11 9:41 ` Punit Agrawal 2017-10-11 9:41 ` [PATCH 1/3] irqchip/gic-v3: Use resource structure to store redistributor regions Punit Agrawal 2017-10-11 9:41 ` Punit Agrawal 2017-10-11 9:41 ` [PATCH 2/3] irqchip/gic-v3: Report firmwware provided address in case of error Punit Agrawal 2017-10-11 9:41 ` Punit Agrawal 2017-10-11 9:41 ` Punit Agrawal [this message] 2017-10-11 9:41 ` [PATCH 3/3] irqchip/gic-v3: Bounds check redistributor accesses Punit Agrawal 2018-03-13 13:38 ` [3/3] " Lokesh Vutla 2018-03-13 13:38 ` Lokesh Vutla 2018-03-13 14:21 ` Marc Zyngier 2018-03-13 14:21 ` Marc Zyngier 2018-03-13 18:49 ` Nishanth Menon 2018-03-13 18:49 ` Nishanth Menon 2018-03-13 20:19 ` Marc Zyngier 2018-03-13 20:19 ` Marc Zyngier
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