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Fri, 13 Jun 2025 17:44:53 -0700 (PDT) From: Alex Guo To: deller@gmx.de Cc: tzimmermann@suse.de, alexguo1023@gmail.com, gonzalo.silvalde@gmail.com, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH] fbdev: sstfb: Fix potential divide by zero Date: Fri, 13 Jun 2025 20:44:50 -0400 Message-Id: <20250614004450.3096366-1-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 sstfb_check_var. 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/sstfb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/video/fbdev/sstfb.c b/drivers/video/fbdev/sstfb.c index 2ea947f57efb..fd387ca8401b 100644 --- a/drivers/video/fbdev/sstfb.c +++ b/drivers/video/fbdev/sstfb.c @@ -359,7 +359,7 @@ static int sstfb_check_var(struct fb_var_screeninfo *var, int tiles_in_X, real_length; unsigned int freq; - if (sst_calc_pll(PICOS2KHZ(var->pixclock), &freq, &par->pll)) { + if (var->pixclock && sst_calc_pll(PICOS2KHZ(var->pixclock), &freq, &par->pll)) { printk(KERN_ERR "sstfb: Pixclock at %ld KHZ out of range\n", PICOS2KHZ(var->pixclock)); return -EINVAL;