linux-kernel - Re: [PATCH 2/2] mtd: nand: qpic_common: prevent out of bounds access of BAM arrays

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87cybv2032.fsf@bootlin.com>
Date: Mon, 26 May 2025 11:27:45 +0200
From: Miquel Raynal <miquel.raynal@...tlin.com>
To: Gabor Juhos <j4g8y7@...il.com>
Cc: Mark Brown <broonie@...nel.org>,  Md Sadre Alam
 <quic_mdalam@...cinc.com>,  Varadarajan Narayanan
 <quic_varada@...cinc.com>,  Sricharan Ramabadhran
 <quic_srichara@...cinc.com>,  Richard Weinberger <richard@....at>,
  Vignesh Raghavendra <vigneshr@...com>,  linux-spi@...r.kernel.org,
  linux-mtd@...ts.infradead.org,  linux-arm-msm@...r.kernel.org,
  linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] mtd: nand: qpic_common: prevent out of bounds
 access of BAM arrays

Hi Gabor,

On 25/05/2025 at 19:05:36 +02, Gabor Juhos <j4g8y7@...il.com> wrote:

> The common QPIC code does not do any boundary checking when it handles
> the command elements and scatter gater list arrays of a BAM transaction,
> thus it allows to access out of bounds elements in those.
>
> Although it is the responsibility of the given driver to allocate enough
> space for all possible BAM transaction variations, however there can be
> mistakes in the driver code which can lead to hidden memory corruption
> issues which are hard to debug.
>
> This kind of problem has been observed during testing the 'spi-qpic-snand'
> driver. Although the driver has been fixed with a preceding patch, but it
> still makes sense to reduce the chance of having such errors again later.
>
> In order to prevent such errors, change the qcom_alloc_bam_transaction()
> function to store the number of elements of the arrays in the
> 'bam_transaction' strucutre during allocation. Also, add sanity checks to
> the qcom_prep_bam_dma_desc_{cmd,data}() functions to avoid using out of
> bounds indices for the arrays.
>
> Tested with the 'spi-qpic-snand' driver only.
>
> Signed-off-by: Gabor Juhos <j4g8y7@...il.com>
> ---
> Preferably, this should go in via the SPI tree along with the previous
> patch. It is not a strict requirement though, in the case it gets
> included separately through the mtd tree it reveals the bug fixed in
> the first patch.

Sorry, didn't see that in the first place. Fine by me.

> ---
>  drivers/mtd/nand/qpic_common.c       | 28 ++++++++++++++++++++++++----
>  include/linux/mtd/nand-qpic-common.h |  8 ++++++++
>  2 files changed, 32 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mtd/nand/qpic_common.c b/drivers/mtd/nand/qpic_common.c
> index e0ed25b5afea9b289b767cd3d9c2d7572ed52008..fb1f81e4bdacaa3e81660a20e164926c64633513 100644
> --- a/drivers/mtd/nand/qpic_common.c
> +++ b/drivers/mtd/nand/qpic_common.c
> @@ -15,6 +15,13 @@
>  #include <linux/slab.h>
>  #include <linux/mtd/nand-qpic-common.h>
>  
> +static inline int qcom_err_bam_array_full(struct qcom_nand_controller *nandc,
> +					  const char *name)
> +{
> +	dev_err(nandc->dev, "BAM %s array is full\n", name);
> +	return -EINVAL;
> +}

This is rather uncommon, I don't know if it's very relevant to do
that. Please drop this static inline function.

Thanks,
Miquèl