linux_ioctl: Refactor some v4l2 struct converters

According to the C standard, it is invalid to copy beyond the end of an
object, even if that object is obviously a member of a larger object (a
struct, in this case).

Appease the standard and Coverity by refactoring the copy in a
straightforward way.  No functional change.

Reported by:	Coverity (CWE-120)
CIDs:		1007819, 1007820, 1007821, 1007822, 1009668, 1009669
Security:	no (false positive detection)
Sponsored by:	Dell EMC Isilon
This commit is contained in:
Conrad Meyer 2017-04-13 17:34:51 +00:00
parent 0a600b6312
commit c6943f3abc

@ -3185,7 +3185,12 @@ linux_to_bsd_v4l2_standard(struct l_v4l2_standard *lvstd, struct v4l2_standard *
{
vstd->index = lvstd->index;
vstd->id = lvstd->id;
memcpy(&vstd->name, &lvstd->name, sizeof(*lvstd) - offsetof(struct l_v4l2_standard, name));
CTASSERT(sizeof(vstd->name) == sizeof(lvstd->name));
memcpy(vstd->name, lvstd->name, sizeof(vstd->name));
vstd->frameperiod = lvstd->frameperiod;
vstd->framelines = lvstd->framelines;
CTASSERT(sizeof(vstd->reserved) == sizeof(lvstd->reserved));
memcpy(vstd->reserved, lvstd->reserved, sizeof(vstd->reserved));
return (0);
}
@ -3194,7 +3199,12 @@ bsd_to_linux_v4l2_standard(struct v4l2_standard *vstd, struct l_v4l2_standard *l
{
lvstd->index = vstd->index;
lvstd->id = vstd->id;
memcpy(&lvstd->name, &vstd->name, sizeof(*lvstd) - offsetof(struct l_v4l2_standard, name));
CTASSERT(sizeof(vstd->name) == sizeof(lvstd->name));
memcpy(lvstd->name, vstd->name, sizeof(lvstd->name));
lvstd->frameperiod = vstd->frameperiod;
lvstd->framelines = vstd->framelines;
CTASSERT(sizeof(vstd->reserved) == sizeof(lvstd->reserved));
memcpy(lvstd->reserved, vstd->reserved, sizeof(lvstd->reserved));
return (0);
}