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Fri, 13 Jun 2025 18:03:20 -0700 (PDT) From: Alex Guo To: deller@gmx.de Cc: FlorianSchandinat@gmx.de, alexguo1023@gmail.com, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH] fbdev: via: hw: Fix potential divide by zero Date: Fri, 13 Jun 2025 21:03:18 -0400 Message-Id: <20250614010318.3128558-1-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_fill_crtc_timing. Similar crashes have happened in other fbdev drivers. We fix this by checking whether 'pixclock' is zero. Similar commit: commit 16844e58704 ("video: fbdev: tridentfb: Error out if 'pixclock' equals zero") Signed-off-by: Alex Guo --- drivers/video/fbdev/via/hw.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/video/fbdev/via/hw.c b/drivers/video/fbdev/via/hw.c index 66afd7be00cc..31e0cac91889 100644 --- a/drivers/video/fbdev/via/hw.c +++ b/drivers/video/fbdev/via/hw.c @@ -1488,8 +1488,9 @@ void viafb_fill_crtc_timing(const struct fb_var_screeninfo *var, if (viaparinfo->chip_info->gfx_chip_name != UNICHROME_CLE266 && viaparinfo->chip_info->gfx_chip_name != UNICHROME_K400) viafb_load_FIFO_reg(iga, var->xres, var->yres); - - viafb_set_vclock(PICOS2KHZ(var->pixclock) * 1000, iga); + + if (var->pixclock) + viafb_set_vclock(PICOS2KHZ(var->pixclock) * 1000, iga); } void viafb_init_chip_info(int chip_type)