Kernel crash in sysrq_handle_crash

Issue

• My box crashed and had the following backtrace:

PID: 6837   TASK: ffff880037862040  CPU: 0   COMMAND: "bash"
 #0 [ffff88003dcf59e0] machine_kexec at ffffffff81038f3b
 #1 [ffff88003dcf5a40] crash_kexec at ffffffff810c5d92
 #2 [ffff88003dcf5b10] oops_end at ffffffff8152b510
 #3 [ffff88003dcf5b40] no_context at ffffffff8104a00b
 #4 [ffff88003dcf5b90] __bad_area_nosemaphore at ffffffff8104a295
 #5 [ffff88003dcf5be0] bad_area at ffffffff8104a3be
 #6 [ffff88003dcf5c10] __do_page_fault at ffffffff8104ab6f
 #7 [ffff88003dcf5d30] do_page_fault at ffffffff8152d45e
 #8 [ffff88003dcf5d60] page_fault at ffffffff8152a815
    [exception RIP: sysrq_handle_crash+22]
    RIP: ffffffff8134b6c6  RSP: ffff88003dcf5e18  RFLAGS: 00010096
    RAX: 0000000000000010  RBX: 0000000000000063  RCX: 0000000000000000
    RDX: 0000000000000000  RSI: 0000000000000000  RDI: 0000000000000063
    RBP: ffff88003dcf5e18   R8: 0000000000000000   R9: ffffffff81645da0
    R10: 0000000000000001  R11: 0000000000000000  R12: 0000000000000000
    R13: ffffffff81b01a40  R14: 0000000000000286  R15: 0000000000000004
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #9 [ffff88003dcf5e20] __handle_sysrq at ffffffff8134b982
#10 [ffff88003dcf5e70] write_sysrq_trigger at ffffffff8134ba3e
#11 [ffff88003dcf5ea0] proc_reg_write at ffffffff811f328e
#12 [ffff88003dcf5ef0] vfs_write at ffffffff81188f78
#13 [ffff88003dcf5f30] sys_write at ffffffff81189871
#14 [ffff88003dcf5f80] system_call_fastpath at ffffffff8100b072
    RIP: 000000388d4db790  RSP: 00007fff44365340  RFLAGS: 00010206
    RAX: 0000000000000001  RBX: ffffffff8100b072  RCX: 0000000000000400
    RDX: 0000000000000002  RSI: 00007fe4a40ee000  RDI: 0000000000000001
    RBP: 00007fe4a40ee000   R8: 000000000000000a   R9: 00007fe4a40de700
    R10: 0000000000000000  R11: 0000000000000246  R12: 0000000000000002
    R13: 000000388d78e780  R14: 0000000000000002  R15: 000000388d78e780
    ORIG_RAX: 0000000000000001  CS: 0033  SS: 002b

• I also see this in the log:

Pid: 6837, comm: bash Not tainted 2.6.32-431.el6.x86_64 #1 Red Hat KVM
RIP: 0010:[<ffffffff8134b6c6>]  [<ffffffff8134b6c6>] sysrq_handle_crash+0x16/0x20
RSP: 0018:ffff88003dcf5e18  EFLAGS: 00010096
RAX: 0000000000000010 RBX: 0000000000000063 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000063
RBP: ffff88003dcf5e18 R08: 0000000000000000 R09: ffffffff81645da0
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff81b01a40 R14: 0000000000000286 R15: 0000000000000004
FS:  00007fe4a40de700(0000) GS:ffff880002200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000003e29a000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process bash (pid: 6837, threadinfo ffff88003dcf4000, task ffff880037862040)
Stack:
 ffff88003dcf5e68 ffffffff8134b982 ffff880037a508c0 ffff880000000000
<d> 0000000000000300 0000000000000002 ffff88003e0cabc0 00007fe4a40ee000
<d> 0000000000000002 fffffffffffffffb ffff88003dcf5e98 ffffffff8134ba3e
Call Trace:
 [<ffffffff8134b982>] __handle_sysrq+0x132/0x1a0
 [<ffffffff8134ba3e>] write_sysrq_trigger+0x4e/0x50
 [<ffffffff811f328e>] proc_reg_write+0x7e/0xc0
 [<ffffffff81188f78>] vfs_write+0xb8/0x1a0
 [<ffffffff81189871>] sys_write+0x51/0x90
 [<ffffffff810e1e5e>] ? __audit_syscall_exit+0x25e/0x290
 [<ffffffff8100b072>] system_call_fastpath+0x16/0x1b
Code: d0 88 81 a3 1c fe 81 c9 c3 66 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 0f 1f 44 00 00 c7 05 0d 07 75 00 01 00 00 00 0f ae f8 <c6> 04 25 00 00 00 00 01 c9 c3 55 48 89 e5 0f 1f 44 00 00 8d 47
RIP  [<ffffffff8134b6c6>] sysrq_handle_crash+0x16/0x20
 RSP <ffff88003dcf5e18>
CR2: 0000000000000000