Re: [PATCH v3 1/3] fbdev: bound mode sysfs output to the sysfs buffer

Helge Deller <[email protected]> Sat, 18 Jul 2026 22:04:41 +0200
Newsgroups org.kernel.vger.linux-fbdev,org.freedesktop.lists.dri-devel,org.kernel.vger.linux-kernel,org.kernel.vger.stable
Message-ID <[email protected]>
On 7/2/26 01:42, Melbin K Mathew wrote:
> mode_string() uses snprintf() which can return a value larger than the
> remaining buffer space. show_modes() accumulates the return value into i
> without checking whether i has reached PAGE_SIZE, causing the offset to
> advance past the sysfs buffer if the modelist is long enough.
> 
> Add a size parameter to mode_string() and use scnprintf() to return
> only the bytes actually written. Add an early return when offset
> already exceeds the buffer. In show_modes(), stop accumulating once
> the buffer is full.
> 
> Cc: [email protected]
> Signed-off-by: Melbin K Mathew <[email protected]>
> ---
>   drivers/video/fbdev/core/fbsysfs.c | 15 ++++++++++-----
>   1 file changed, 10 insertions(+), 5 deletions(-)
I've applied the series to fbdev git tree for further testing.

Thanks!
Helge