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Fri, 13 Jun 2025 17:54:31 -0700 (PDT) From: Alex Guo To: deller@gmx.de, FlorianSchandinat@gmx.de Cc: alexguo1023@gmail.com, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH] fbdev: via: Fix potential divide by zero Date: Fri, 13 Jun 2025 20:54:28 -0400 Message-Id: <20250614005428.3112421-1-alexguo1023@gmail.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Variable var->pixclock can be set by user. In case it equals to zero, divide by zero would occur in viafb_dvi_set_mode. Similar crashes have happened in other fbdev drivers. We fix this by checking whether 'pixclock' is zero. Signed-off-by: Alex Guo --- drivers/video/fbdev/via/dvi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/video/fbdev/via/dvi.c b/drivers/video/fbdev/via/dvi.c index 27990a73bfa3..0ba248b7b360 100644 --- a/drivers/video/fbdev/via/dvi.c +++ b/drivers/video/fbdev/via/dvi.c @@ -166,7 +166,7 @@ void viafb_dvi_set_mode(const struct fb_var_screeninfo *var, int maxPixelClock; maxPixelClock = viaparinfo->shared->tmds_setting_info.max_pixel_clock; - if (maxPixelClock && PICOS2KHZ(var->pixclock) / 1000 > maxPixelClock) { + if (maxPixelClock && var->pixclock && PICOS2KHZ(var->pixclock) / 1000 > maxPixelClock) { rb_mode = viafb_get_best_rb_mode(var->xres, var->yres, 60); if (rb_mode) viafb_fill_var_timing_info(&dvi_var, rb_mode);