CVE-2022-48987: linux kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: media: v4l2-dv-timings.c: fix too strict blanking sanity checks Sanity checks were added to verify the v4l2_bt_timings blanking fields in order to avoid integer overflows when userspace passes weird values. But that assumed that userspace would correctly fill in the front porch, backporch and sync values, but sometimes all you know is the total blanking, which is then assigned to just one of these fields. And that can fail with these checks. So instead set a maximum for the total horizontal and vertical blanking and check that each field remains below that. That is still sufficient to avoid integer overflows, but it also allows for more flexibility in how userspace fills in these fields.
CVE-2022-48987CVSS 5.5Linux

CVE-2022-48987: linux kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: media: v4l2-dv-timings.c: fix too strict blanking sanity checks Sanity checks were added to verify the v4l2_bt_timings blanking fields in order to avoid integer overflows when userspace passes weird values. But that assumed that userspace would correctly fill in the front porch, backporch and sync values, but sometimes all you know is the total blanking, which is then assigned to just one of these fields. And that can fail with these checks. So instead set a maximum for the total horizontal and vertical blanking and check that each field remains below that. That is still sufficient to avoid integer overflows, but it also allows for more flexibility in how userspace fills in these fields.

CVSS
5.5 MEDIUM
EPSS
16.02%
Known exploited
not in KEV
Product
linux kernel

What is known

In the Linux kernel, the following vulnerability has been resolved: media: v4l2-dv-timings.c: fix too strict blanking sanity checks Sanity checks were added to verify the v4l2_bt_timings blanking fields in order to avoid integer overflows when userspace passes weird values. But that assumed that userspace would correctly fill in the front porch, backporch and sync values, but sometimes all you know is the total blanking, which is then assigned to just one of these fields. And that can fail with these checks. So instead set a maximum for the total horizontal and vertical blanking and check that each field remains below that. That is still sufficient to avoid integer overflows, but it also allows for more flexibility in how userspace fills in these fields.

Sources

Security newsletter

Get new CVE alerts before they become an incident

We send selected infrastructure threats in English, with practical notes for DataHouse environments.

  • DataHouse: server administration and secure cloud
  • Hostilla.pl: hosting and mail services
  • SecDNS.pl: free DNS security layer