diff mbox

video: fbdev: sm501fb: fix potential null pointer dereference on fbi

Message ID 20171110173231.24598-1-colin.king@canonical.com (mailing list archive)
State New, archived
Headers show

Commit Message

Colin King Nov. 10, 2017, 5:32 p.m. UTC 
From: Colin Ian King <colin.king@canonical.com>

The pointer fbi is dereferenced with par = fbi->par before there is a
null check on fbi, hence there is a potential null pointer dereference
on a null par.  Fix this by moving the dereference after the null
pointer check.

Detected by CoverityScan, CID#1461301 ("Dereference before null check")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/video/fbdev/sm501fb.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Bartlomiej Zolnierkiewicz Nov. 17, 2017, 4:03 p.m. UTC | #1 
On Friday, November 10, 2017 05:32:31 PM Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> The pointer fbi is dereferenced with par = fbi->par before there is a
> null check on fbi, hence there is a potential null pointer dereference
> on a null par.  Fix this by moving the dereference after the null
> pointer check.
> 
> Detected by CoverityScan, CID#1461301 ("Dereference before null check")
> 
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Patch queued for 4.15, thanks.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

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diff mbox

Patch

diff --git a/drivers/video/fbdev/sm501fb.c b/drivers/video/fbdev/sm501fb.c
index 8d4fdb373299..6f0a19501c6a 100644
--- a/drivers/video/fbdev/sm501fb.c
+++ b/drivers/video/fbdev/sm501fb.c
@@ -2100,11 +2100,12 @@  static int sm501fb_suspend_fb(struct sm501fb_info *info,
 			      enum sm501_controller head)
 {
 	struct fb_info *fbi = info->fb[head];
-	struct sm501fb_par *par = fbi->par;
+	struct sm501fb_par *par;
 
 	if (!fbi)
 		return 0;
 
+	par = fbi->par;
 	if (par->screen.size == 0)
 		return 0;
 
@@ -2150,11 +2151,12 @@  static void sm501fb_resume_fb(struct sm501fb_info *info,
 			      enum sm501_controller head)
 {
 	struct fb_info *fbi = info->fb[head];
-	struct sm501fb_par *par = fbi->par;
+	struct sm501fb_par *par;
 
 	if (!fbi)
 		return;
 
+	par = fbi->par;
 	if (par->screen.size == 0)
 		return;