UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

media: pci: ttpci: av7110: fix possible buffer overflow caused by bad DMA value in debiirq() 

The value av7110->debi_virt is stored in DMA memory, and it is assigned
to data, and thus data[0] can be modified at any time by malicious
hardware. In this case, "if (data[0] < 2)" can be passed, but then
data[0] can be changed into a large number, which may cause buffer
overflow when the code "av7110->ci_slot[data[0]]" is used.

To fix this possible bug, data[0] is assigned to a local variable, which
replaces the use of data[0].

Signed-off-by: Jia-Ju Bai <baijiaju@tsinghua.edu.cn>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Jia-Ju Bai 2020-05-30 16:42:08 +02:00 committed by Mauro Carvalho Chehab
parent bc76369b89
commit 6499a0db9b
1 changed files with 3 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/media/pci/ttpci/av7110.c
View File

@ -406,14 +406,15 @@ static void debiirq(unsigned long cookie)
case DATA_CI_GET:
{
u8 *data = av7110->debi_virt;
u8 data_0 = data[0];
if ((data[0] < 2) && data[2] == 0xff) {
if (data_0 < 2 && data[2] == 0xff) {
int flags = 0;
if (data[5] > 0)
flags |= CA_CI_MODULE_PRESENT;
if (data[5] > 5)
flags |= CA_CI_MODULE_READY;
av7110->ci_slot[data[0]].flags = flags;
av7110->ci_slot[data_0].flags = flags;
} else
ci_get_data(&av7110->ci_rbuffer,
av7110->debi_virt,