diff options
| author | Zheyu Ma <zheyuma97@gmail.com> | 2021-07-14 04:09:22 +0000 |
|---|---|---|
| committer | Sam Ravnborg <sam@ravnborg.org> | 2021-07-19 20:46:32 +0200 |
| commit | 98a65439172dc69cb16834e62e852afc2adb83ed (patch) | |
| tree | abd0b244c63d26fecbb8f577bcf8931fb1059f41 /drivers/video | |
| parent | 5cc4e71f0199391b0e311c44e79736c13eea269d (diff) | |
video: fbdev: kyro: fix a DoS bug by restricting user input
The user can pass in any value to the driver through the 'ioctl'
interface. The driver dost not check, which may cause DoS bugs.
The following log reveals it:
divide error: 0000 [#1] PREEMPT SMP KASAN PTI
RIP: 0010:SetOverlayViewPort+0x133/0x5f0 drivers/video/fbdev/kyro/STG4000OverlayDevice.c:476
Call Trace:
kyro_dev_overlay_viewport_set drivers/video/fbdev/kyro/fbdev.c:378 [inline]
kyrofb_ioctl+0x2eb/0x330 drivers/video/fbdev/kyro/fbdev.c:603
do_fb_ioctl+0x1f3/0x700 drivers/video/fbdev/core/fbmem.c:1171
fb_ioctl+0xeb/0x130 drivers/video/fbdev/core/fbmem.c:1185
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x19b/0x220 fs/ioctl.c:739
do_syscall_64+0x32/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1626235762-2590-1-git-send-email-zheyuma97@gmail.com
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/fbdev/kyro/fbdev.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/video/fbdev/kyro/fbdev.c b/drivers/video/fbdev/kyro/fbdev.c index 8fbde92ae8b9..4b8c7c16b1df 100644 --- a/drivers/video/fbdev/kyro/fbdev.c +++ b/drivers/video/fbdev/kyro/fbdev.c @@ -372,6 +372,11 @@ static int kyro_dev_overlay_viewport_set(u32 x, u32 y, u32 ulWidth, u32 ulHeight /* probably haven't called CreateOverlay yet */ return -EINVAL; + if (ulWidth == 0 || ulWidth == 0xffffffff || + ulHeight == 0 || ulHeight == 0xffffffff || + (x < 2 && ulWidth + 2 == 0)) + return -EINVAL; + /* Stop Ramdac Output */ DisableRamdacOutput(deviceInfo.pSTGReg); |