[Valgrind-users] Strange (at least to me) valgrind messages

[Tyson W. <twh...@gm...>]

I've been working on debugging someone else's MPI code and am getting error messages that seem pretty strange to me

==32704== Memcheck, a memory error detector
==32704== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==32704== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info

...

==32704== Unaddressable byte(s) found during client check request
...
==32704==  Address 0x243e6040 is 16,384 bytes inside a block of size 1,048,576 alloc'd
...

and

==32704== Invalid read of size 8
...
==32704==  Address 0x22fe2040 is 0 bytes inside a block of size 1,048,576 alloc'd
...

and

==32704== Invalid write of size 8
...
==32704==  Address 0x22fe2048 is 8 bytes inside a block of size 1,048,576 alloc'd
...

and on and on and on ...

Are these valid errors?  Everything I found online seemed to indicate that error addresses should not fall entirely inside allocated blocks.

Thanks!  -Tyson

PS:  This was run with --track-origins=yes and --leak-check=yes.