Kernel panic in BalloonDeflate() function of unsigned kernel module "vmmemctl".

Issue

• RHEL-5 server running on VMware Virtual Platform crashed with following call traces;

Unable to handle kernel paging request at ffff81081751dff8 RIP: 
 [<ffffffff8840b43e>] :vmmemctl:BalloonDeflate+0x62/0x160
PGD 10063 PUD 0 
Oops: 0000 [1] SMP 
last sysfs file: /block/ram0/dev
CPU 0 
Modules linked in: nfs nfs_acl autofs4 hidp rfcomm l2cap bluetooth lockd sunrpc be2iscsi ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp bnx2i cnic ipv6 xfrm_nalgo crypto_api uio cxgb3i libcxgbi cxgb3 8021q libiscsi_tcp libiscsi2 scsi_transport_iscsi2 scsi_transport_iscsi vsock(U) vmmemctl(U) dm_multipath scsi_dh video backlight sbs power_meter hwmon i2c_ec dell_wmi wmi button battery asus_acpi acpi_memhotplug ac lp i2c_piix4 sg floppy ide_cd i2c_core tpm_tis parport_pc serio_raw cdrom tpm vmci(U) pcspkr e1000 tpm_bios parport shpchp vmxnet3(U) vmxnet(U) pvscsi(U) dm_raid45 dm_message dm_region_hash dm_mem_cache dm_snapshot dm_zero dm_mirror dm_log dm_mod ata_piix libata mptspi mptscsih mptbase scsi_transport_spi sd_mod scsi_mod ext3 jbd uhci_hcd ohci_hcd ehci_hcd
Pid: 2053, comm: vmmemctl Tainted: G     --------------------    2.6.18-371.8.1.el5 #1
RIP: 0010:[<ffffffff8840b43e>]  [<ffffffff8840b43e>] :vmmemctl:BalloonDeflate+0x62/0x160
RSP: 0018:ffff8100bd155e30  EFLAGS: 00010286
RAX: 00000000ffffffff RBX: ffffffff884169c0 RCX: 00000001a60e0001
RDX: 00000000ffffffff RSI: 00000000000028df RDI: ffffffff884169c0
RBP: 00000000000009e9 R08: ffffffff88416a6c R09: 000000000000003e
R10: ffff8100bfe2c038 R11: 0000000000000246 R12: ffff81001751e000
R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff800a3d4a
FS:  0000000000000000(0000) GS:ffffffff80436000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: ffff81081751dff8 CR3: 00000000b7d86000 CR4: 00000000000006a0
Process vmmemctl (pid: 2053, threadinfo ffff8100bd154000, task ffff8100be67d040)
Stack:  0000000000000000 ffff8100bd155ea0 0000000000000000 0000000000000282
 ffff8100bd3c9de8 ffffffff8840abf7 000028df00000202 ffffffff8840a716
 0000000000000000 ffff8100be67d040 ffffffff800a3f62 ffff8100bd155eb8
Call Trace:
 [<ffffffff8840abf7>] :vmmemctl:Balloon_QueryAndExecute+0x67/0x70
 [<ffffffff8840a716>] :vmmemctl:vmballoon_poll_loop+0xfa/0x10c
 [<ffffffff800a3f62>] autoremove_wake_function+0x0/0x2e
 [<ffffffff800a3f62>] autoremove_wake_function+0x0/0x2e
 [<ffffffff8840a61c>] :vmmemctl:vmballoon_poll_loop+0x0/0x10c
 [<ffffffff80032c68>] kthread+0xfe/0x132
 [<ffffffff8005dfc1>] child_rip+0xa/0x11
 [<ffffffff800a3d4a>] keventd_create_kthread+0x0/0xc4
 [<ffffffff80032b6a>] kthread+0x0/0x132
 [<ffffffff8005dfb7>] child_rip+0x0/0x11

Code: 49 8b 3c d4 75 37 49 8d 8c 24 48 1f 00 00 49 8b b4 24 48 1f 
RIP  [<ffffffff8840b43e>] :vmmemctl:BalloonDeflate+0x62/0x160
 RSP <ffff8100bd155e30>