Re: [PATCH 1/1] iscsi_ibft: KASAN false positive failure occurs in ibft_init()

From: Konrad Rzeszutek Wilk
Date: Wed Jan 27 2021 - 13:45:54 EST


On Tue, Jan 26, 2021 at 01:03:21PM -0500, George Kennedy wrote:
> During boot of kernel with CONFIG_KASAN the following KASAN false
> positive failure will occur when ibft_init() reads the
> ACPI iBFT table: BUG: KASAN: use-after-free in ibft_init
>
> The ACPI iBFT table is not allocated, and the iscsi driver uses
> a pointer to it to calculate checksum, etc. KASAN complains
> about this pointer with use-after-free, which this is not.
>

Andrey, Alexander, Dmitry,

I think this is the right way for this, but was wondering if you have
other suggestions?

Thanks!
> Signed-off-by: George Kennedy <george.kennedy@xxxxxxxxxx>
> ---
> drivers/firmware/Makefile | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
> index 5e013b6..30ddab5 100644
> --- a/drivers/firmware/Makefile
> +++ b/drivers/firmware/Makefile
> @@ -14,6 +14,9 @@ obj-$(CONFIG_INTEL_STRATIX10_SERVICE) += stratix10-svc.o
> obj-$(CONFIG_INTEL_STRATIX10_RSU) += stratix10-rsu.o
> obj-$(CONFIG_ISCSI_IBFT_FIND) += iscsi_ibft_find.o
> obj-$(CONFIG_ISCSI_IBFT) += iscsi_ibft.o
> +KASAN_SANITIZE_iscsi_ibft.o := n
> +KCOV_INSTRUMENT_iscsi_ibft.o := n
> +
> obj-$(CONFIG_FIRMWARE_MEMMAP) += memmap.o
> obj-$(CONFIG_RASPBERRYPI_FIRMWARE) += raspberrypi.o
> obj-$(CONFIG_FW_CFG_SYSFS) += qemu_fw_cfg.o
> --
> 1.8.3.1
>