Syscall param poll(ufds.fd) points to uninitialised byte(s) ... by 0x........: main (badpoll.c:22) Address 0x........ is 8 bytes inside a block of size 15 alloc'd at 0x........: malloc (vg_replace_malloc.c:...) by 0x........: main (badpoll.c:12) Syscall param poll(ufds.revents) points to unaddressable byte(s) ... by 0x........: main (badpoll.c:22) Address 0x........ is 0 bytes after a block of size 15 alloc'd at 0x........: malloc (vg_replace_malloc.c:...) by 0x........: main (badpoll.c:12)