From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Date: Mon, 30 Jan 2017 15:59:22 +0000 Subject: Re: [PATCH v1] video : fbdev : stifb :- Handle return NULL error from ioremap_nocache. Message-Id: <1759269.Z5Z5RrJiUP@amdc3058> List-Id: References: <1484734911-5299-1-git-send-email-arvind.yadav.cs@gmail.com> In-Reply-To: <1484734911-5299-1-git-send-email-arvind.yadav.cs@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Arvind Yadav Cc: jejb@parisc-linux.org, deller@gmx.de, linux-parisc@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org Hi, On Wednesday, January 18, 2017 03:51:51 PM Arvind Yadav wrote: > Here, If ioremap_nocache will fail. It will return NULL. > Kernel can run into a NULL-pointer dereference. > This error check will avoid NULL pointer dereference. > > Signed-off-by: Arvind Yadav Thanks, I queued your patch with some minor changes for 4.11 (you can see the final version of the patch below). Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics From: Arvind Yadav Subject: [PATCH v1] video: fbdev: stifb: handle NULL return value from ioremap_nocache Add missing error check for ioremap_nocache() failure (prevents NULL pointer dereference on error). Cc: "James E.J. Bottomley" Cc: Helge Deller Signed-off-by: Arvind Yadav [b.zolnierkie: minor fixes] Signed-off-by: Bartlomiej Zolnierkiewicz --- drivers/video/fbdev/stifb.c | 4 ++++ 1 file changed, 4 insertions(+) Index: b/drivers/video/fbdev/stifb.c =================================--- a/drivers/video/fbdev/stifb.c 2017-01-30 16:55:15.766435453 +0100 +++ b/drivers/video/fbdev/stifb.c 2017-01-30 16:55:15.750435453 +0100 @@ -1294,6 +1294,10 @@ static int __init stifb_init_fb(struct s strcpy(fix->id, "stifb"); info->fbops = &stifb_ops; info->screen_base = ioremap_nocache(REGION_BASE(fb,1), fix->smem_len); + if (!info->screen_base) { + printk(KERN_ERR "stifb: failed to map memory\n"); + goto out_err0; + } info->screen_size = fix->smem_len; info->flags = FBINFO_DEFAULT | FBINFO_HWACCEL_COPYAREA; info->pseudo_palette = &fb->pseudo_palette;