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| author | Zheyu Ma <zheyuma97@gmail.com> | 2022-04-04 16:47:23 +0800 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2022-04-11 08:23:50 +0200 |
| commit | 7015bb57c304bad7289e872c2c5c587adee3a756 (patch) | |
| tree | c82d6daf29a2baeba74279ce42bd8f8c5bb21f6c /drivers/video/fbdev/s3fb.c | |
| parent | e1e965156438a3662dbb151d892ada834214c833 (diff) | |
| download | linux-7015bb57c304bad7289e872c2c5c587adee3a756.tar.gz | |
video: fbdev: s3fb: 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 in s3fb_check_var(). The following log reveals it: divide error: 0000 [#1] PREEMPT SMP KASAN PTI RIP: 0010:s3fb_check_var+0x3f3/0x530 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>
Diffstat (limited to 'drivers/video/fbdev/s3fb.c')
| -rw-r--r-- | drivers/video/fbdev/s3fb.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/video/fbdev/s3fb.c b/drivers/video/fbdev/s3fb.c index 5c74253e7b2c..b93c8eb02336 100644 --- a/drivers/video/fbdev/s3fb.c +++ b/drivers/video/fbdev/s3fb.c @@ -549,6 +549,9 @@ static int s3fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info) int rv, mem, step; u16 m, n, r; + if (!var->pixclock) + return -EINVAL; + /* Find appropriate format */ rv = svga_match_format (s3fb_formats, var, NULL); |