diff options
| author | Zheyu Ma | 2022-04-04 16:47:21 +0800 |
|---|---|---|
| committer | Helge Deller | 2022-04-11 08:23:50 +0200 |
| commit | 16844e5870424c2728486dc0c0300ebf7fa09ad6 (patch) | |
| tree | 7bc4ca2a1a6e01f825165d585d9ce37b87419f36 | |
| parent | f2bfd792c1ed4b1e0578db3fcdb0879dc87fe027 (diff) | |
video: fbdev: tridentfb: Error out if 'pixclock' equals zero
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.
The following log reveals it:
divide error: 0000 [#1] PREEMPT SMP KASAN PTI
RIP: 0010:tridentfb_check_var+0x853/0xe60
Call Trace:
<TASK>
fb_set_var+0x367/0xeb0
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>
| -rw-r--r-- | drivers/video/fbdev/tridentfb.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/video/fbdev/tridentfb.c b/drivers/video/fbdev/tridentfb.c index 4d20cb557ff0..319131bd72cf 100644 --- a/drivers/video/fbdev/tridentfb.c +++ b/drivers/video/fbdev/tridentfb.c @@ -996,6 +996,9 @@ static int tridentfb_check_var(struct fb_var_screeninfo *var, int ramdac = 230000; /* 230MHz for most 3D chips */ debug("enter\n"); + if (!var->pixclock) + return -EINVAL; + /* check color depth */ if (bpp == 24) bpp = var->bits_per_pixel = 32; |