commit 6ad959b6703e2c4c5d7af03b4cfd5ff608036339 upstream.
The commit 04e5eac8f3ab("fbdev: savage: Error out if pixclock equals zero")
checks the value of pixclock to avoid divide-by-zero error. However
the function savagefb_probe doesn't handle the error return of
savagefb_check_var. When pixclock is 0, it will cause divide-by-zero error.
Fixes: 04e5eac8f3ab ("fbdev: savage: Error out if pixclock equals zero")
Signed-off-by: Cai Xinchen <caixinchen1@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 04e5eac8f3ab2ff52fa191c187a46d4fdbc1e288 ]
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-by-zero error.
Although pixclock is checked in savagefb_decode_var(), but it is not
checked properly in savagefb_probe(). Fix this by checking whether
pixclock is zero in the function savagefb_check_var() before
info->var.pixclock is used as the divisor.
This is similar to CVE-2022-3061 in i740fb which was fixed by
commit 15cf0b8.
Signed-off-by: Fullway Wang <fullwaywang@outlook.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
