BUG #15312: Possible access to unintended variable in "postgres/src/backend/postmaster/pgstat.c" line 2698

The following bug has been logged on the website:

Bug reference: 15312
Logged by: Petru-Florin Mihancea
Email address: petrum(at)gmail(dot)com
PostgreSQL version: Unsupported/Unknown
Operating system: Macosx
Description:

While experimenting with a CodeSonar plugin we develop, we noticed a
potential bug in file "postgres/src/backend/postmaster/pgstat.c" line 2698
function CreateSharedBackendStatus.

/* Create or attach to the shared activity buffer */
BackendActivityBufferSize = mul_size(pgstat_track_activity_query_size,
NumBackendStatSlots);
BackendActivityBuffer = (char *)
ShmemInitStruct("Backend Activity Buffer",
BackendActivityBufferSize,
&found);
if (!found)
{
MemSet(BackendActivityBuffer, 0, size); //HERE

/* Initialize st_activity pointers. */
buffer = BackendActivityBuffer;
for (i = 0; i < NumBackendStatSlots; i++)
{
BackendStatusArray[i].st_activity_raw = buffer;
buffer += pgstat_track_activity_query_size;
}
}

Shouldn't BackendActivityBufferSize be accessed in the marked line instead
of size?

Thanks,
Petru Florin Mihancea