From: Niklas Cassel <niklas.cassel@linaro.org>
To: Jingoo Han <jingoohan1@gmail.com>,
Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Cc: Niklas Cassel <niklas.cassel@linaro.org>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Bjorn Helgaas <bhelgaas@google.com>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] PCI: dwc: fix find_next_bit() usage
Date: Wed, 4 Sep 2019 18:03:38 +0200 [thread overview]
Message-ID: <20190904160339.2800-1-niklas.cassel@linaro.org> (raw)
find_next_bit() takes a parameter of size long, and performs arithmetic
that assumes that the argument is of size long.
Therefore we cannot pass a u32, since this will cause find_next_bit()
to read outside the stack buffer and will produce the following print:
BUG: KASAN: stack-out-of-bounds in find_next_bit+0x38/0xb0
Fixes: 1b497e6493c4 ("PCI: dwc: Fix uninitialized variable in dw_handle_msi_irq()")
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
---
drivers/pci/controller/dwc/pcie-designware-host.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index d3156446ff27..45f21640c977 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -78,7 +78,8 @@ static struct msi_domain_info dw_pcie_msi_domain_info = {
irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
{
int i, pos, irq;
- u32 val, num_ctrls;
+ unsigned long val;
+ u32 status, num_ctrls;
irqreturn_t ret = IRQ_NONE;
num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
@@ -86,14 +87,14 @@ irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
for (i = 0; i < num_ctrls; i++) {
dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_STATUS +
(i * MSI_REG_CTRL_BLOCK_SIZE),
- 4, &val);
- if (!val)
+ 4, &status);
+ if (!status)
continue;
ret = IRQ_HANDLED;
+ val = status;
pos = 0;
- while ((pos = find_next_bit((unsigned long *) &val,
- MAX_MSI_IRQS_PER_CTRL,
+ while ((pos = find_next_bit(&val, MAX_MSI_IRQS_PER_CTRL,
pos)) != MAX_MSI_IRQS_PER_CTRL) {
irq = irq_find_mapping(pp->irq_domain,
(i * MAX_MSI_IRQS_PER_CTRL) +
--
2.21.0
next reply other threads:[~2019-09-04 16:03 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-04 16:03 Niklas Cassel [this message]
2019-09-12 11:31 ` [PATCH] PCI: dwc: fix find_next_bit() usage Gustavo Pimentel
2019-09-12 13:04 ` Andrew Murray
2019-09-13 21:57 ` Bjorn Andersson
2019-10-15 15:34 ` Lorenzo Pieralisi
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