Re: New Defects reported by Coverity Scan for Linux

[Bjorn Helgaas <helgaas@kernel.org>]

[+cc Om, just noticed your series of pcie-tegra194 updates]

On Mon, Jun 21, 2021 at 07:44:26AM -0500, Bjorn Helgaas wrote:
> FYI.  Looks like we rely directy on the result of a read from the
> device to index an array, probably not a great idea.
> 
> On Mon, Jun 21, 2021 at 07:45:30AM +0000, scan-admin@coverity.com wrote:
> > Hi,
> > 
> > Please find the latest report on new defect(s) introduced to Linux found with Coverity Scan.
> > 
> > 7 new defect(s) introduced to Linux found with Coverity Scan.
> > 4 defect(s), reported by Coverity Scan earlier, were marked fixed in the recent build analyzed by Coverity Scan.
> 
> 
> > ** CID 1475616:  Memory - illegal accesses  (OVERRUN)
> > /drivers/pci/controller/dwc/pcie-tegra194.c: 994 in tegra_pcie_dw_start_link()
> > 
> > 
> > ________________________________________________________________________________________________________
> > *** CID 1475616:  Memory - illegal accesses  (OVERRUN)
> > /drivers/pci/controller/dwc/pcie-tegra194.c: 994 in tegra_pcie_dw_start_link()
> > 988     		retry = false;
> > 989     		goto retry_link;
> > 990     	}
> > 991     
> > 992     	speed = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA) &
> > 993     		PCI_EXP_LNKSTA_CLS;
> > >>>     CID 1475616:  Memory - illegal accesses  (OVERRUN)
> > >>>     Overrunning array "pcie_gen_freq" of 4 4-byte elements at element index 4294967295 (byte offset 17179869183) using index "speed - 1U" (which evaluates to 4294967295).
> > 994     	clk_set_rate(pcie->core_clk, pcie_gen_freq[speed - 1]);
> > 995     
> > 996     	tegra_pcie_enable_interrupts(pp);
> > 997     
> > 998     	return 0;
> > 999     }
> > 
> > ** CID 1475402:  Memory - illegal accesses  (OVERRUN)
> > /drivers/pci/controller/dwc/pcie-tegra194.c: 457 in tegra_pcie_ep_irq_thread()
> > 
> > 
> > ________________________________________________________________________________________________________
> > *** CID 1475402:  Memory - illegal accesses  (OVERRUN)
> > /drivers/pci/controller/dwc/pcie-tegra194.c: 457 in tegra_pcie_ep_irq_thread()
> > 451     	struct tegra_pcie_dw *pcie = arg;
> > 452     	struct dw_pcie *pci = &pcie->pci;
> > 453     	u32 val, speed;
> > 454     
> > 455     	speed = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA) &
> > 456     		PCI_EXP_LNKSTA_CLS;
> > >>>     CID 1475402:  Memory - illegal accesses  (OVERRUN)
> > >>>     Overrunning array "pcie_gen_freq" of 4 4-byte elements at element index 4294967295 (byte offset 17179869183) using index "speed - 1U" (which evaluates to 4294967295).
> > 457     	clk_set_rate(pcie->core_clk, pcie_gen_freq[speed - 1]);
> > 458     
> > 459     	/* If EP doesn't advertise L1SS, just return */
> > 460     	val = dw_pcie_readl_dbi(pci, pcie->cfg_link_cap_l1sub);
> > 461     	if (!(val & (PCI_L1SS_CAP_ASPM_L1_1 | PCI_L1SS_CAP_ASPM_L1_2)))
> > 462     		return IRQ_HANDLED;