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Date:   Mon, 30 Dec 2019 12:03:40 -0500
From:   Konrad Rzeszutek Wilk <konrad@darnok.org>
To:     Lubomir Rintel <lkundrak@v3.sk>
Cc:     Konrad Rzeszutek Wilk <konrad@kernel.org>,
        Peter Jones <pjones@redhat.com>, linux-kernel@vger.kernel.org
Subject: Re: [RESEND PATCH] iscsi_ibft: Don't limits Targets and NICs to two
Message-ID: <20191230170340.GA23237@localhost.localdomain>
References: <20191221070956.268321-1-lkundrak@v3.sk>
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On Sat, Dec 21, 2019 at 08:09:56AM +0100, Lubomir Rintel wrote:
> According to iSCSI Boot Firmware Table Version 1.03 [1], the length of
> the control table is ">= 18", where the optional expansion structure
> pointer follow the mandatory ones. This allows for more than two NICs
> and Targets.
> 
> [1] ftp://ftp.software.ibm.com/systems/support/bladecenter/iscsi_boot_firmware_table_v1.03.pdf
> 
> Let's enforce the minimum length of the control structure instead
> instead of limiting it to the smallest allowed size.

Hi!

Do you have an example of such iBFT table? Thanks
> 
> Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
> ---
>  drivers/firmware/iscsi_ibft.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/firmware/iscsi_ibft.c b/drivers/firmware/iscsi_ibft.c
> index 7e12cbdf957cc..96758b71a8db8 100644
> --- a/drivers/firmware/iscsi_ibft.c
> +++ b/drivers/firmware/iscsi_ibft.c
> @@ -104,6 +104,7 @@ struct ibft_control {
>  	u16 tgt0_off;
>  	u16 nic1_off;
>  	u16 tgt1_off;
> +	u16 expansion[0];
>  } __attribute__((__packed__));
>  
>  struct ibft_initiator {
> @@ -235,7 +236,7 @@ static int ibft_verify_hdr(char *t, struct ibft_hdr *hdr, int id, int length)
>  				"found %d instead!\n", t, id, hdr->id);
>  		return -ENODEV;
>  	}
> -	if (hdr->length != length) {
> +	if (length && hdr->length != length) {
>  		printk(KERN_ERR "iBFT error: We expected the %s " \
>  				"field header.length to have %d but " \
>  				"found %d instead!\n", t, length, hdr->length);
> @@ -749,16 +750,16 @@ static int __init ibft_register_kobjects(struct acpi_table_ibft *header)
>  	control = (void *)header + sizeof(*header);
>  	end = (void *)control + control->hdr.length;
>  	eot_offset = (void *)header + header->header.length - (void *)control;
> -	rc = ibft_verify_hdr("control", (struct ibft_hdr *)control, id_control,
> -			     sizeof(*control));
> +	rc = ibft_verify_hdr("control", (struct ibft_hdr *)control, id_control, 0);
>  
>  	/* iBFT table safety checking */
>  	rc |= ((control->hdr.index) ? -ENODEV : 0);
> +	rc |= ((control->hdr.length < sizeof(*control)) ? -ENODEV : 0);
>  	if (rc) {
>  		printk(KERN_ERR "iBFT error: Control header is invalid!\n");
>  		return rc;
>  	}
> -	for (ptr = &control->initiator_off; ptr < end; ptr += sizeof(u16)) {
> +	for (ptr = &control->initiator_off; ptr + sizeof(u16) <= end; ptr += sizeof(u16)) {
>  		offset = *(u16 *)ptr;
>  		if (offset && offset < header->header.length &&
>  						offset < eot_offset) {
> -- 
> 2.24.1
>