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PCI: dwc: Fix find_next_bit() usage

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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: 1b497e6493 ("PCI: dwc: Fix uninitialized variable in dw_handle_msi_irq()")
Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
This commit is contained in:
Niklas Cassel
2019-09-04 18:03:38 +02:00
committed by Lorenzo Pieralisi
parent 54ecb8f702
commit 1137e61dcb
1 changed files with 6 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
drivers/pci/controller/dwc/pcie-designware-host.c
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@@ -78,7 +78,8 @@ static struct msi_domain_info dw_pcie_msi_domain_info = {
irqreturn_t dw_handle_msi_irq(struct pcie_port *pp) irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
{ {
int i, pos, irq; int i, pos, irq;
u32 val, num_ctrls; unsigned long val;
u32 status, num_ctrls;
irqreturn_t ret = IRQ_NONE; irqreturn_t ret = IRQ_NONE;
num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL; 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++) { for (i = 0; i < num_ctrls; i++) {
dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_STATUS + dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_STATUS +
(i * MSI_REG_CTRL_BLOCK_SIZE), (i * MSI_REG_CTRL_BLOCK_SIZE),
4, &val); 4, &status);
if (!val) if (!status)
continue; continue;
ret = IRQ_HANDLED; ret = IRQ_HANDLED;
val = status;
pos = 0; pos = 0;
while ((pos = find_next_bit((unsigned long *) &val, while ((pos = find_next_bit(&val, MAX_MSI_IRQS_PER_CTRL,
MAX_MSI_IRQS_PER_CTRL,
pos)) != MAX_MSI_IRQS_PER_CTRL) { pos)) != MAX_MSI_IRQS_PER_CTRL) {
irq = irq_find_mapping(pp->irq_domain, irq = irq_find_mapping(pp->irq_domain,
(i * MAX_MSI_IRQS_PER_CTRL) + (i * MAX_MSI_IRQS_PER_CTRL) +