Random kernel panic crashes

I have for a long time (a few years) had problems with my iMac crashing randomly. I always thought the crashes were related to some faulty system files, as I used to get error messages popping up regarding system files not being installed properly. A few days ago I did a clean install however, but I'm still experiencing these seemingly random crashes. The screen goes black and I get the "Your computer restarted because of a problem." kernel panic message. Sometimes the computer crashes several times in a row. Here's the crash report:

Anonymous UUID:

0A6B098A-3FFE-1EEB-A8B5-99A45AF08474

Mon Apr 27 14:49:06 2015

*** Panic Report ***

panic(cpu 4 caller 0xffffff801596cffd): "a freed zone element has been modified in zone buf.8192: expected 0x53521cb96302965 but found 0xffffffffffffffff, bits changed 0xfacade3469cfd69a, at offset 8184 of 8192 in element 0xffffff804640d000, cookies 0x3f00117357ff4384 0x53521cb96302965"@/SourceCache/xnu/xnu-2782.20.48/osfmk/kern/zalloc.c:496

Backtrace (CPU 4), Frame : Return Address

0xffffff811f3dac90 : 0xffffff801592bda1

0xffffff811f3dad10 : 0xffffff801596cffd

0xffffff811f3dad80 : 0xffffff801596ca71

0xffffff811f3dadc0 : 0xffffff801596bc8e

0xffffff811f3daef0 : 0xffffff8015b2c901

0xffffff811f3daf20 : 0xffffff8015b2aea3

0xffffff811f3daf80 : 0xffffff8015b2a9c6

0xffffff811f3db060 : 0xffffff8015b2c180

0xffffff811f3db0c0 : 0xffffff8015d24f55

0xffffff811f3db120 : 0xffffff8015d746eb

0xffffff811f3db1c0 : 0xffffff8015d6f61c

0xffffff811f3db2d0 : 0xffffff8015d2eac5

0xffffff811f3db330 : 0xffffff8015d2cc70

0xffffff811f3db3a0 : 0xffffff8015d486f6

0xffffff811f3db400 : 0xffffff8015d47ab0

0xffffff811f3dbab0 : 0xffffff8015d41e07

0xffffff811f3dbbd0 : 0xffffff8015b6f7f6

0xffffff811f3dbc60 : 0xffffff8015b5eeca

0xffffff811f3dbd70 : 0xffffff8015b55778

0xffffff811f3dbf50 : 0xffffff8015e4ba86

0xffffff811f3dbfb0 : 0xffffff8015a35376

BSD process name corresponding to current thread: mds

Mac OS version:

14D136

Kernel version:

Darwin Kernel Version 14.3.0: Mon Mar 23 11:59:05 PDT 2015; root:xnu-2782.20.48~5/RELEASE_X86_64

Kernel UUID: 4B3A11F4-77AA-3D27-A22D-81A1BC5B504D

Kernel slide:

0x0000000015600000

Kernel text base: 0xffffff8015800000

__HIB text base: 0xffffff8015700000

System model name: iMac11,3 (Mac-F2238BAE)

System uptime in nanoseconds: 66609710718546

last loaded kext at 51292906552375: com.apple.driver.AppleUSBCDC 4.3.3b1 (addr 0xffffff7f985cd000, size 20480)

last unloaded kext at 51352970071954: com.apple.driver.AppleUSBCDC 4.3.3b1 (addr 0xffffff7f985cd000, size 16384)

loaded kexts:

com.apple.driver.AppleBluetoothMultitouch 85.3

com.apple.driver.AudioAUUC 1.70

com.apple.driver.AppleHWSensor 1.9.5d0

com.apple.driver.AGPM 110.19.5

com.apple.filesystems.autofs 3.0

com.apple.iokit.IOBluetoothSerialManager 4.3.4f4

com.apple.driver.AppleOSXWatchdog 1

com.apple.driver.AppleMikeyHIDDriver 124

com.apple.driver.AppleMikeyDriver 272.18

com.apple.driver.AppleHDA 272.18

com.apple.driver.AppleUpstreamUserClient 3.6.1

com.apple.kext.AMDFramebuffer 1.3.2

com.apple.iokit.IOUserEthernet 1.0.1

com.apple.AMDRadeonX3000 1.3.2

com.apple.Dont_Steal_Mac_OS_X 7.0.0

com.apple.driver.AppleHWAccess 1

com.apple.iokit.BroadcomBluetoothHostControllerUSBTransport 4.3.4f4

com.apple.kext.AMD5000Controller 1.3.2

com.apple.driver.AppleHV 1

com.apple.driver.AppleIntelSlowAdaptiveClocking 4.0.0

com.apple.driver.AppleBacklight 170.7.4

com.apple.driver.AppleLPC 1.7.3

com.apple.driver.ACPI_SMC_PlatformPlugin 1.0.0

com.apple.driver.AppleMCCSControl 1.2.11

com.apple.driver.AppleUSBCardReader 3.5.5

com.apple.driver.AppleIRController 327.5

com.apple.AppleFSCompression.AppleFSCompressionTypeDataless 1.0.0d1

com.apple.AppleFSCompression.AppleFSCompressionTypeZlib 1.0.0d1

com.apple.BootCache 36

com.apple.iokit.SCSITaskUserClient 3.7.5

com.apple.driver.XsanFilter 404

com.apple.iokit.IOAHCIBlockStorage 2.7.1

com.apple.driver.AppleUSBHub 705.4.2

com.apple.driver.AppleFWOHCI 5.5.2

com.apple.iokit.AppleBCM5701Ethernet 10.1.3

com.apple.driver.AirPort.Atheros40 700.74.5

com.apple.driver.AppleAHCIPort 3.1.2

com.apple.driver.AppleUSBEHCI 705.4.14

com.apple.driver.AppleACPIButtons 3.1

com.apple.driver.AppleRTC 2.0

com.apple.driver.AppleHPET 1.8

com.apple.driver.AppleSMBIOS 2.1

com.apple.driver.AppleACPIEC 3.1

com.apple.driver.AppleAPIC 1.7

com.apple.driver.AppleIntelCPUPowerManagementClient 218.0.0

com.apple.nke.applicationfirewall 161

com.apple.security.quarantine 3

com.apple.security.TMSafetyNet 8

com.apple.driver.AppleIntelCPUPowerManagement 218.0.0

com.apple.driver.AppleBluetoothHIDKeyboard 176.2

com.apple.driver.AppleHIDKeyboard 176.2

com.apple.driver.IOBluetoothHIDDriver 4.3.4f4

com.apple.driver.AppleMultitouchDriver 263.9.1

com.apple.kext.triggers 1.0

com.apple.iokit.IOSerialFamily 11

com.apple.driver.DspFuncLib 272.18

com.apple.kext.OSvKernDSPLib 1.15

com.apple.iokit.IOSurface 97.4

com.apple.iokit.IOAcceleratorFamily2 156.14

com.apple.iokit.IOUSBUserClient 705.4.0

com.apple.iokit.IOBluetoothHostControllerUSBTransport 4.3.4f4

com.apple.iokit.IOBluetoothFamily 4.3.4f4

com.apple.kext.AMDSupport 1.3.2

com.apple.AppleGraphicsDeviceControl 3.10.22

com.apple.driver.AppleHDAController 272.18

com.apple.iokit.IOHDAFamily 272.18

com.apple.iokit.IOAudioFamily 203.3

com.apple.vecLib.kext 1.2.0

com.apple.iokit.IOSlowAdaptiveClockingFamily 1.0.0

com.apple.driver.AppleBacklightExpert 1.1.0

com.apple.iokit.IONDRVSupport 2.4.1

com.apple.driver.AppleSMBusPCI 1.0.12d1

com.apple.driver.IOPlatformPluginLegacy 1.0.0

com.apple.driver.IOPlatformPluginFamily 5.9.1d7

com.apple.iokit.IOFireWireIP 2.2.6

com.apple.driver.AppleSMC 3.1.9

com.apple.driver.AppleSMBusController 1.0.13d1

com.apple.iokit.IOGraphicsFamily 2.4.1

com.apple.iokit.IOSCSIBlockCommandsDevice 3.7.5

com.apple.iokit.IOUSBMassStorageClass 3.7.2

com.apple.iokit.IOUSBHIDDriver 705.4.0

com.apple.iokit.IOSCSIMultimediaCommandsDevice 3.7.5

com.apple.iokit.IOBDStorageFamily 1.7

com.apple.iokit.IODVDStorageFamily 1.7.1

com.apple.iokit.IOCDStorageFamily 1.7.1

com.apple.driver.AppleUSBMergeNub 705.4.0

com.apple.driver.AppleUSBComposite 705.4.9

com.apple.iokit.IOAHCISerialATAPI 2.6.1

com.apple.iokit.IOSCSIArchitectureModelFamily 3.7.5

com.apple.iokit.IOFireWireFamily 4.5.6

com.apple.iokit.IOEthernetAVBController 1.0.3b3

com.apple.driver.mDNSOffloadUserClient 1.0.1b8

com.apple.iokit.IO80211Family 730.60

com.apple.iokit.IONetworkingFamily 3.2

com.apple.iokit.IOAHCIFamily 2.7.5

com.apple.iokit.IOUSBFamily 720.4.4

com.apple.driver.AppleEFINVRAM 2.0

com.apple.driver.AppleEFIRuntime 2.0

com.apple.iokit.IOHIDFamily 2.0.0

com.apple.iokit.IOSMBusFamily 1.1

com.apple.security.sandbox 300.0

com.apple.kext.AppleMatch 1.0.0d1

com.apple.driver.AppleKeyStore 2

com.apple.driver.AppleMobileFileIntegrity 1.0.5

com.apple.driver.AppleCredentialManager 1.0

com.apple.driver.DiskImages 396

com.apple.iokit.IOStorageFamily 2.0

com.apple.iokit.IOReportFamily 31

com.apple.driver.AppleFDEKeyStore 28.30

com.apple.driver.AppleACPIPlatform 3.1

com.apple.iokit.IOPCIFamily 2.9

com.apple.iokit.IOACPIFamily 1.4

com.apple.kec.corecrypto 1.0

com.apple.kec.Libm 1

com.apple.kec.pthread 1

Model: iMac11,3, BootROM IM112.0057.B01, 4 processors, Intel Core i7, 2.93 GHz, 8 GB, SMC 1.59f2

Graphics: ATI Radeon HD 5750, ATI Radeon HD 5750, PCIe, 1024 MB

Memory Module: BANK 0/DIMM0, 2 GB, DDR3, 1333 MHz, 0x80CE, 0x4D34373142353637334648302D4348392020

Memory Module: BANK 1/DIMM0, 2 GB, DDR3, 1333 MHz, 0x80CE, 0x4D34373142353637334648302D4348392020

Memory Module: BANK 0/DIMM1, 2 GB, DDR3, 1333 MHz, 0x80CE, 0x4D34373142353637334648302D4348392020

Memory Module: BANK 1/DIMM1, 2 GB, DDR3, 1333 MHz, 0x80CE, 0x4D34373142353637334648302D4348392020

AirPort: spairport_wireless_card_type_airport_extreme (0x168C, 0x8F), Atheros 9280: 4.0.74.0-P2P

Bluetooth: Version 4.3.4f4 15601, 3 services, 27 devices, 1 incoming serial ports

Network Service: Ethernet, Ethernet, en0

Serial ATA Device: ST31000528AS, 1 TB

Serial ATA Device: OPTIARC DVD RW AD-5680H

USB Device: Hub

USB Device: Internal Memory Card Reader

USB Device: BRCM2046 Hub

USB Device: Bluetooth USB Host Controller

USB Device: Hub

USB Device: USB to ATA/ATAPI bridge

USB Device: IR Receiver

USB Device: Built-in iSight

Thunderbolt Bus: