video: fbdev: kyro: fix a DoS bug by restricting user input
[ Upstream commit 98a65439172dc69cb16834e62e852afc2adb83ed ]
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
Signed-off-by: Sasha Levin <sashal@kernel.org>
1 file changed