RHEL6: corrupted ELF header in /proc/vmcore causes kdump to fail

Issue

On some systems, kdump frequently fails on one of our server with the following message.

[Tue Jul 21 07:23:19 2015]Saving vmcore-dmesg.txt
[Tue Jul 21 07:23:19 2015]Cannot malloc 5999218776 bytes
[Tue Jul 21 07:23:19 2015]Saving vmcore-dmesg.txt failed

The problem is caused by a corrupted elf header in /proc/vmcore with a 6GB note section. When kdump succeeds, the size of the note section is 18620 bytes.

The issue occurs in 3 out of 4 attempts to create a kdump. It is not important how the kdump is triggered, i.e.

# echo c > /proc/sysrq-trigger

can be used.
When the issue occurs, "vmcore-incomplete" is output to the kdumps directory below /var/crash/ and above mentioned error is output to the console.

When /proc/vmcore in 2nd kernel is checked, it can be observed that the size of note0 turns to a big value:

# objdump --section-headers issue_vmcore > issue_vmcore_objdump.log 
# head issue_vmcore_objdump.log
issue_vmcore:     file format elf64-x86-64
Sections:
      Idx Name          Size      VMA               LMA               File off  Algn
        0 note0         16594d058  0000000000000000  0000000000000000  00000238  2**0
                        CONTENTS, READONLY
        1 .reg/0        000000d8  0000000000000000  0000000000000000  000002bc  2**2
                        CONTENTS
        2 .reg          000000d8  0000000000000000  0000000000000000  000002bc  2**2