Re: [PATCH] hwmon: (pmbus/q54sj108a2) fix stack overflow in debugfs read

[Guenter Roeck]

On 3/3/26 17:00, Sanman Pradhan wrote:
>  From 166d8a9220dc783b752cb212937a31e6e1adc811 Mon Sep 17 00:00:00 2001
> From: Sanman Pradhan <psanman@xxxxxxxxxxx>
> Date: Tue, 3 Mar 2026 16:22:08 -0800
> Subject: [PATCH] hwmon: (pmbus/q54sj108a2) fix stack overflow in debugfs read
>
> The q54sj108a2_debugfs_read function suffers from a stack buffer overflow
> due to incorrect arguments passed to bin2hex(). The function currently
> passes 'data' as the destination and 'data_char' as the source.
>
> Because bin2hex() converts each input byte into two hex characters, a
> 32-byte block read results in 64 bytes of output. Since 'data' is only
> 34 bytes (I2C_SMBUS_BLOCK_MAX + 2), this writes 30 bytes past the end
> of the buffer onto the stack.
>
> Additionally, the arguments were swapped: it was reading from the
> zero-initialized 'data_char' and writing to 'data', resulting in
> all-zero output regardless of the actual I2C read.
>
> Fix this by:
> 1. Expanding 'data_char' to 66 bytes to safely hold the hex output.
> 2. Correcting the bin2hex() argument order and using the actual read count.
> 3. Using a pointer to select the correct output buffer for the final
>     simple_read_from_buffer call.
>
> Fixes: d014538aa385 ("hwmon: (pmbus) Driver for Delta power supplies Q54SJ108A2")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Sanman Pradhan <psanman@xxxxxxxxxxx>

This patch does not apply.

ERROR: patch seems to be corrupt (line wrapped?)
#235: FILE: drivers/hwmon/pmbus/q54sj108a2.c:78:
	int idx = *idxp;

Guenter