leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

video: fbdev: vt8623fb: Error out if 'pixclock' equals zero

Browse Source 
The userspace program could pass any values to the driver through
ioctl() interface. If the driver doesn't check the value of 'pixclock',
it may cause divide error.

Fix this by checking whether 'pixclock' is zero in the function
vt8623fb_check_var().

The following log reveals it:
 divide error: 0000 [#1] PREEMPT SMP KASAN PTI
 RIP: 0010:vt8623fb_set_par+0xecd/0x2210
 Call Trace:
  <TASK>
  fb_set_var+0x604/0xeb0
  do_fb_ioctl+0x234/0x670
  fb_ioctl+0xdd/0x130
  do_syscall_64+0x3b/0x90

Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
Zheyu Ma 2022-04-04 16:47:20 +08:00 committed by Helge Deller
parent 213e2df473
commit f2bfd792c1
1 changed files with 3 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
drivers/video/fbdev/vt8623fb.c
View File

@ -321,6 +321,9 @@ static int vt8623fb_check_var(struct fb_var_screeninfo *var, struct fb_info *inf
{
int rv, mem, step;
if (!var->pixclock)
return -EINVAL;
/* Find appropriate format */
rv = svga_match_format (vt8623fb_formats, var, NULL);
if (rv < 0)