RE: [PATCH] mtd: spi-nor: debugfs: fix out-of-bounds read in spi_nor_params_show()

From: <Takahiro.Kuwano@infineon.com>
To: <tudor.ambarus@linaro.org>, <pratyush@kernel.org>,
	<mwalle@kernel.org>, <miquel.raynal@bootlin.com>,
	<richard@nod.at>, <vigneshr@ti.com>
Cc: <p.yadav@ti.com>, <michael@walle.cc>,
	<linux-mtd@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
	<stable@vger.kernel.org>
Subject: RE: [PATCH] mtd: spi-nor: debugfs: fix out-of-bounds read in spi_nor_params_show()
Date: Tue, 21 Apr 2026 14:32:45 +0000	[thread overview]
Message-ID: <308e7510718f46169d9465658f2c385a@infineon.com> (raw)
In-Reply-To: <20260417-fix-oob-read-spi-nor-v1-1-2132e61a684a@linaro.org>

> Sashiko noticed an out-of-bounds read [1].
> 
> In spi_nor_params_show(), the snor_f_names array is passed to
> spi_nor_print_flags() using sizeof(snor_f_names).
> 
> Since snor_f_names is an array of pointers, sizeof() returns the total
> number of bytes occupied by the pointers
>         (element_count * sizeof(void *))
> rather than the element count itself. On 64-bit systems, this makes the
> passed length 8x larger than intended.
> 
> Inside spi_nor_print_flags(), the 'names_len' argument is used to
> bounds-check the 'names' array access. An out-of-bounds read occurs
> if a flag bit is set that exceeds the array's actual element count
> but is within the inflated byte-size count.
> 
> Correct this by using ARRAY_SIZE() to pass the actual number of
> string pointers in the array.
> 
> Cc: stable@vger.kernel.org
> Fixes: 0257be79fc4a ("mtd: spi-nor: expose internal parameters via debugfs")
> Closes: https://sashiko.dev/#/patchset/20260417-die-erase-fix-v2-1-73bb7004ebad%40infineon.com [1]
> Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

Reviewed-by: Takahiro Kuwano <takahiro.kuwano@infineon.com>

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