ci starts bisection 2025-10-23 20:25:53.74996646 +0000 UTC m=+84865.867183269 bisecting cause commit starting from 43e9ad0c55a369ecc84a4788d06a8a6bfa634f1c building syzkaller on c0460fcde7051a8d07612ec2a17718d3c3019bb0 ensuring issue is reproducible on original commit 43e9ad0c55a369ecc84a4788d06a8a6bfa634f1c testing commit 43e9ad0c55a369ecc84a4788d06a8a6bfa634f1c gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 3488c4cf2da90965a1e16427b844d3bc19e70ea60b00b35521aad8ef97815260 all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] check whether we can drop unnecessary instrumentation disabling configs for [ubsan bug_or_warning locking atomic_sleep hang memleak], they are not needed testing commit 43e9ad0c55a369ecc84a4788d06a8a6bfa634f1c gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 78ba49069285ca72bf2cd27033d2c4623525da0501033bb7ea9f060fe725d836 all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] the bug reproduces without the instrumentation disabling configs for [locking atomic_sleep hang memleak ubsan bug_or_warning], they are not needed kconfig minimization: base=4116 full=8528 leaves diff=2154 split chunks (needed=false): <2154> split chunk #0 of len 2154 into 5 parts testing without sub-chunk 1/5 disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed testing commit 43e9ad0c55a369ecc84a4788d06a8a6bfa634f1c gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 796cd9d67ae52f58b832924cb47cebd9bca26d638a6b7ea78b069401d797015a all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] the chunk can be dropped testing without sub-chunk 2/5 disabling configs for [locking atomic_sleep hang memleak ubsan bug_or_warning], they are not needed testing commit 43e9ad0c55a369ecc84a4788d06a8a6bfa634f1c gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 7519245473b8242f9c66c2a4440db202a7962e3216564e70c3a09e40b8a739b9 all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] the chunk can be dropped testing without sub-chunk 3/5 disabling configs for [bug_or_warning locking atomic_sleep hang memleak ubsan], they are not needed testing commit 43e9ad0c55a369ecc84a4788d06a8a6bfa634f1c gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 39e736497afbcdb08bb86c660c970e07c0e9890e745e7eacd29c2c562c9ac363 all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] the chunk can be dropped testing without sub-chunk 4/5 disabling configs for [atomic_sleep hang memleak ubsan bug_or_warning locking], they are not needed testing commit 43e9ad0c55a369ecc84a4788d06a8a6bfa634f1c gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 5b37cfd5f2c4120d72cf596e5d113d268b1c1672c5bc9873c04b447bed98fc48 all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] the chunk can be dropped testing without sub-chunk 5/5 disabling configs for [ubsan bug_or_warning locking atomic_sleep hang memleak], they are not needed testing commit 43e9ad0c55a369ecc84a4788d06a8a6bfa634f1c gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: ec99aeba3fbc2144b4455384e23a10309abb7b52cf73f158c6b15fa5308ab2cf all runs: OK false negative chance: 0.000 minimized to 430 configs; suspects: [ARCH_ENABLE_MEMORY_HOTREMOVE ATM BCMA BLK_DEV_ZONED BPF_SYSCALL CARDBUS CFG80211 CFG80211_WEXT CMA COMMON_CLK CONTIG_ALLOC DVB_CORE EXTCON GPIOLIB HID_ZEROPLUS I2C_MUX IIO IOMMUFD IRQ_REMAP KVM KVM_INTEL LIBNVDIMM MEDIA_ANALOG_TV_SUPPORT MEDIA_CAMERA_SUPPORT MEDIA_CEC_SUPPORT MEDIA_CONTROLLER MEDIA_DIGITAL_TV_SUPPORT MEDIA_RADIO_SUPPORT MEDIA_SDR_SUPPORT MEDIA_SUPPORT MEDIA_TEST_SUPPORT MEDIA_USB_SUPPORT MEMORY_HOTPLUG MEMORY_HOTREMOVE MFD_VIPERBOARD NOP_USB_XCEIV PARPORT PCCARD PCMCIA PHONET RADIO_ADAPTERS RADIO_SI470X RADIO_SI4713 RC_CORE RFKILL SND SOUND SPI SSB TAP TARGET_CORE TUN USB_ALI_M5632 USB_AMD5536UDC USB_AN2720 USB_APPLEDISPLAY USB_ARMLINUX USB_ATM USB_BDC_UDC USB_BELKIN USB_C67X00_HCD USB_CATC USB_CDC_PHONET USB_CDNS2_UDC USB_CDNS3 USB_CDNS3_GADGET USB_CDNS3_HOST USB_CDNS3_PCI_WRAP USB_CDNSP_GADGET USB_CDNSP_HOST USB_CDNSP_PCI USB_CDNS_HOST USB_CDNS_SUPPORT USB_CHAOSKEY USB_CHIPIDEA USB_CHIPIDEA_GENERIC USB_CHIPIDEA_HOST USB_CHIPIDEA_MSM USB_CHIPIDEA_NPCM USB_CHIPIDEA_PCI USB_CHIPIDEA_UDC USB_CONFIGFS USB_CONFIGFS_ACM USB_CONFIGFS_ECM USB_CONFIGFS_ECM_SUBSET USB_CONFIGFS_EEM USB_CONFIGFS_F_FS USB_CONFIGFS_F_HID USB_CONFIGFS_F_LB_SS USB_CONFIGFS_F_MIDI USB_CONFIGFS_F_MIDI2 USB_CONFIGFS_F_PRINTER USB_CONFIGFS_F_TCM USB_CONFIGFS_F_UAC1 USB_CONFIGFS_F_UAC1_LEGACY USB_CONFIGFS_F_UAC2 USB_CONFIGFS_F_UVC USB_CONFIGFS_MASS_STORAGE USB_CONFIGFS_NCM USB_CONFIGFS_OBEX USB_CONFIGFS_PHONET USB_CONFIGFS_RNDIS USB_CONFIGFS_SERIAL USB_CONN_GPIO USB_CXACRU USB_CYPRESS_CY7C63 USB_CYTHERM USB_DSBR USB_DUMMY_HCD USB_DWC2 USB_DWC2_HOST USB_DWC2_PCI USB_DWC3 USB_DWC3_GADGET USB_DWC3_GENERIC_PLAT USB_DWC3_HAPS USB_DWC3_OF_SIMPLE USB_DWC3_PCI USB_DWC3_ULPI USB_DYNAMIC_MINORS USB_EG20T USB_EHCI_FSL USB_EHCI_HCD_PLATFORM USB_EHCI_ROOT_HUB_TT USB_EHSET_TEST_FIXTURE USB_EMI26 USB_EMI62 USB_EPSON2888 USB_EZUSB_FX2 USB_FEW_INIT_RETRIES USB_F_ACM USB_F_ECM USB_F_EEM USB_F_FS USB_F_HID USB_F_MASS_STORAGE USB_F_MIDI USB_F_MIDI2 USB_F_NCM USB_F_OBEX USB_F_PHONET USB_F_PRINTER USB_F_RNDIS USB_F_SERIAL USB_F_SS_LB USB_F_SUBSET USB_F_TCM USB_F_UAC1 USB_F_UAC1_LEGACY USB_F_UAC2 USB_F_UVC USB_GADGET USB_GADGETFS USB_GADGET_DEBUG_FILES USB_GADGET_DEBUG_FS USB_GL860 USB_GOKU USB_GR_UDC USB_GSPCA USB_GSPCA_BENQ USB_GSPCA_CONEX USB_GSPCA_CPIA1 USB_GSPCA_DTCS033 USB_GSPCA_ETOMS USB_GSPCA_FINEPIX USB_GSPCA_JEILINJ USB_GSPCA_JL2005BCD USB_GSPCA_KINECT USB_GSPCA_KONICA USB_GSPCA_MARS USB_GSPCA_MR97310A USB_GSPCA_NW80X USB_GSPCA_OV519 USB_GSPCA_OV534 USB_GSPCA_OV534_9 USB_GSPCA_PAC207 USB_GSPCA_PAC7302 USB_GSPCA_PAC7311 USB_GSPCA_SE401 USB_GSPCA_SN9C2028 USB_GSPCA_SN9C20X USB_GSPCA_SONIXB USB_GSPCA_SONIXJ USB_GSPCA_SPCA1528 USB_GSPCA_SPCA500 USB_GSPCA_SPCA501 USB_GSPCA_SPCA505 USB_GSPCA_SPCA506 USB_GSPCA_SPCA508 USB_GSPCA_SPCA561 USB_GSPCA_SQ905 USB_GSPCA_SQ905C USB_GSPCA_SQ930X USB_GSPCA_STK014 USB_GSPCA_STK1135 USB_GSPCA_STV0680 USB_GSPCA_SUNPLUS USB_GSPCA_T613 USB_GSPCA_TOPRO USB_GSPCA_TOUPTEK USB_GSPCA_TV8532 USB_GSPCA_VC032X USB_GSPCA_VICAM USB_GSPCA_XIRLINK_CIT USB_GSPCA_ZC3XX USB_HACKRF USB_HCD_BCMA USB_HCD_SSB USB_HSIC_USB3503 USB_HSIC_USB4604 USB_HSO USB_HUB_USB251XB USB_IDMOUSE USB_IOWARRIOR USB_IPHETH USB_ISIGHTFW USB_ISP116X_HCD USB_ISP1301 USB_ISP1760 USB_ISP1760_DUAL_ROLE USB_ISP1760_HCD USB_ISP1761_UDC USB_KAWETH USB_KC2190 USB_KEENE USB_LAN78XX USB_LCD USB_LD USB_LEDS_TRIGGER_USBPORT USB_LED_TRIG USB_LEGOTOWER USB_LGM_PHY USB_LIBCOMPOSITE USB_LINK_LAYER_TEST USB_M5602 USB_MA901 USB_MAX3420_UDC USB_MAX3421_HCD USB_MDC800 USB_MICROTEK USB_MR800 USB_MSI2500 USB_MUSB_DUAL_ROLE USB_MUSB_HDRC USB_NET2280 USB_NET_AQC111 USB_NET_AX88179_178A USB_NET_AX8817X USB_NET_CDCETHER USB_NET_CDC_EEM USB_NET_CDC_MBIM USB_NET_CDC_NCM USB_NET_CDC_SUBSET USB_NET_CDC_SUBSET_ENABLE USB_NET_CH9200 USB_NET_CX82310_ETH USB_NET_DM9601 USB_NET_GL620A USB_NET_HUAWEI_CDC_NCM USB_NET_INT51X1 USB_NET_KALMIA USB_NET_MCS7830 USB_NET_NET1080 USB_NET_PLUSB USB_NET_QMI_WWAN USB_NET_RNDIS_HOST USB_NET_SMSC75XX USB_NET_SMSC95XX USB_NET_SR9700 USB_NET_SR9800 USB_NET_ZAURUS USB_OHCI_HCD_PLATFORM USB_OTG USB_OTG_FSM USB_OXU210HP_HCD USB_PEGASUS USB_PULSE8_CEC USB_PWC USB_PWC_INPUT_EVDEV USB_PXA27X USB_R8A66597 USB_R8A66597_HCD USB_RAINSHADOW_CEC USB_RAREMONO USB_RAW_GADGET USB_RTL8150 USB_RTL8152 USB_RTL8153_ECM USB_S2255 USB_SERIAL USB_SERIAL_AIRCABLE USB_SERIAL_ARK3116 USB_SERIAL_BELKIN USB_SERIAL_CH341 USB_SERIAL_CONSOLE USB_SERIAL_CP210X USB_SERIAL_CYBERJACK USB_SERIAL_CYPRESS_M8 USB_SERIAL_DEBUG USB_SERIAL_DIGI_ACCELEPORT USB_SERIAL_EDGEPORT USB_SERIAL_EDGEPORT_TI USB_SERIAL_EMPEG USB_SERIAL_F81232 USB_SERIAL_F8153X USB_SERIAL_FTDI_SIO USB_SERIAL_GARMIN USB_SERIAL_GENERIC USB_SERIAL_IPAQ USB_SERIAL_IPW USB_SERIAL_IR USB_SERIAL_IUU USB_SERIAL_KEYSPAN USB_SERIAL_KEYSPAN_PDA USB_SERIAL_KLSI USB_SERIAL_KOBIL_SCT USB_SERIAL_MCT_U232 USB_SERIAL_METRO USB_SERIAL_MOS7715_PARPORT USB_SERIAL_MOS7720 USB_SERIAL_MOS7840 USB_SERIAL_MXUPORT USB_SERIAL_NAVMAN USB_SERIAL_OMNINET USB_SERIAL_OPTICON USB_SERIAL_OPTION USB_SERIAL_OTI6858 USB_SERIAL_PL2303 USB_SERIAL_QCAUX USB_SERIAL_QT2 USB_SERIAL_QUALCOMM USB_SERIAL_SAFE USB_SERIAL_SIERRAWIRELESS USB_SERIAL_SIMPLE USB_SERIAL_SPCP8X5 USB_SERIAL_SSU100 USB_SERIAL_SYMBOL USB_SERIAL_TI USB_SERIAL_UPD78F0730 USB_SERIAL_VISOR USB_SERIAL_WHITEHEAT USB_SERIAL_WISHBONE USB_SERIAL_WWAN USB_SERIAL_XR USB_SERIAL_XSENS_MT USB_SEVSEG USB_SI470X USB_SI4713 USB_SIERRA_NET USB_SISUSBVGA USB_SL811_CS USB_SL811_HCD USB_SL811_HCD_ISO USB_SNP_CORE USB_SPEEDTOUCH USB_STORAGE_ALAUDA USB_STORAGE_CYPRESS_ATACB USB_STORAGE_DATAFAB USB_STORAGE_ENE_UB6250 USB_STORAGE_FREECOM USB_STORAGE_ISD200 USB_STORAGE_JUMPSHOT USB_STORAGE_KARMA USB_STORAGE_ONETOUCH USB_STORAGE_SDDR09 USB_STORAGE_SDDR55 USB_STORAGE_USBAT USB_STV06XX USB_TEST USB_TMC USB_TRANCEVIBRATOR USB_UAS USB_UEAGLEATM USB_ULPI_BUS USB_USBNET USB_USS720 USB_U_AUDIO USB_U_ETHER USB_U_SERIAL USB_VIDEO_CLASS USB_VIDEO_CLASS_INPUT_EVDEV USB_VL600 USB_WDM USB_XHCI_DBGCAP USB_XHCI_PCI_RENESAS USB_XHCI_PLATFORM USB_XUSBATM USB_YUREX USERFAULTFD USERIO USER_RETURN_NOTIFIER UVC_COMMON U_SERIAL_CONSOLE V4L2_MEM2MEM_DEV V4L_TEST_DRIVERS VALIDATE_FS_PARSER VDPA VDPA_SIM VDPA_SIM_BLOCK VDPA_SIM_NET VETH VFIO VFIO_DEVICE_CDEV VFIO_PCI VFIO_PCI_CORE VFIO_PCI_INTX VFIO_VIRQFD VGASTATE VHOST VHOST_CROSS_ENDIAN_LEGACY VHOST_IOTLB VHOST_NET VHOST_RING VHOST_TASK VHOST_VDPA VHOST_VSOCK VIDEO VIDEOBUF2_CORE VIDEOBUF2_DMA_CONTIG VIDEOBUF2_DMA_SG VIDEOBUF2_MEMOPS VIDEOBUF2_V4L2 VIDEOBUF2_VMALLOC VIDEOMODE_HELPERS VIDEO_AU0828 VIDEO_AU0828_RC VIDEO_AU0828_V4L2 VIDEO_CS53L32A VIDEO_CX231XX VIDEO_CX231XX_ALSA VIDEO_CX231XX_DVB VIDEO_CX231XX_RC VIDEO_CX2341X VIDEO_CX25840 VIDEO_DEV VIDEO_EM28XX VIDEO_EM28XX_ALSA VIDEO_EM28XX_DVB VIDEO_EM28XX_RC VIDEO_EM28XX_V4L2 VIDEO_GO7007 VIDEO_GO7007_LOADER VIDEO_GO7007_USB VIDEO_GO7007_USB_S2250_BOARD VIDEO_HDPVR VIDEO_MSP3400 VIDEO_PVRUSB2 VIDEO_PVRUSB2_DVB VIDEO_PVRUSB2_SYSFS VIDEO_SAA711X VIDEO_STK1160 VIDEO_TUNER VIDEO_TVEEPROM VIDEO_USBTV VIDEO_V4L2_I2C VIDEO_V4L2_SUBDEV_API VIDEO_V4L2_TPG VIDEO_VICODEC VIDEO_VIM2M VIDEO_VIMC VIDEO_VIVID VIDEO_VIVID_CEC VIDEO_WM8775 VIPERBOARD_ADC VIRTIO_BALLOON VIRTIO_DMA_SHARED_BUFFER VIRTIO_MEM VIRTIO_MMIO VIRTIO_MMIO_CMDLINE_DEVICES VIRTIO_PMEM VIRTIO_VDPA VIRTIO_VSOCKETS VIRTIO_VSOCKETS_COMMON VIRT_WIFI VIRT_XFER_TO_GUEST_WORK VLAN_8021Q VLAN_8021Q_GVRP VLAN_8021Q_MVRP VMAP_PFN VMWARE_VMCI VMXNET3 VP_VDPA VSOCKETS VSOCKETS_DIAG VSOCKETS_LOOPBACK VSOCKMON VT_HW_CONSOLE_BINDING VXFS_FS WANT_DEV_COREDUMP WEXT_CORE WEXT_PROC WIREGUARD WIRELESS WLAN WLAN_VENDOR_ADMTEK WLAN_VENDOR_SILABS X86_FRED X86_SGX X86_SGX_KVM X86_USER_SHADOW_STACK XDP_SOCKETS XDP_SOCKETS_DIAG XFRM_ESPINTCP XFRM_INTERFACE XFRM_IPCOMP XFRM_MIGRATE XFRM_OFFLOAD XFRM_STATISTICS XFRM_SUB_POLICY XFRM_USER_COMPAT XFS_FS XFS_POSIX_ACL XFS_QUOTA XFS_RT XILLYBUS_CLASS XILLYUSB XOR_BLOCKS YENTA YENTA_ENE_TUNE YENTA_O2 YENTA_RICOH YENTA_TI YENTA_TOSHIBA ZEROPLUS_FF ZLIB_DEFLATE ZONEFS_FS ZRAM ZRAM_BACKEND_FORCE_LZO ZRAM_BACKEND_LZO ZRAM_DEF_COMP_LZO ZSMALLOC ZSTD_COMPRESS ZSWAP ZSWAP_COMPRESSOR_DEFAULT_842 ZSWAP_DEFAULT_ON ZSWAP_SHRINKER_DEFAULT_ON] disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed picked [v6.17 v6.16 v6.15 v6.13 v6.11 v6.9 v6.7 v6.5 v6.2 v5.19 v5.16 v5.13 v5.10 v5.7 v5.4 v5.1 v4.19] out of 40 release tags testing release v6.17 testing commit e5f0a698b34ed76002dc5cff3804a61c80233a7a gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 986bf8a5bc2c0ccaddcf4717913cdf5e506ce2778091eefb1068c3002a2efb63 all runs: OK false negative chance: 0.000 # git bisect start 43e9ad0c55a369ecc84a4788d06a8a6bfa634f1c e5f0a698b34ed76002dc5cff3804a61c80233a7a Bisecting: 6444 revisions left to test after this (roughly 13 steps) [f79e772258df311c2cb21594ca0996318e720d28] Merge tag 'media/v6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media testing commit f79e772258df311c2cb21594ca0996318e720d28 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: b57c3a04cd1d3ea83970b9003a71328aec4f292b63d13f5738a969d71fdc41e4 all runs: OK false negative chance: 0.000 # git bisect good f79e772258df311c2cb21594ca0996318e720d28 Bisecting: 3315 revisions left to test after this (roughly 12 steps) [bf897d2626abe4559953342e2f7dda05d034c8c7] Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost testing commit bf897d2626abe4559953342e2f7dda05d034c8c7 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 51ffb595e1e0588f24da56fb5ded988f437148bae5d2c265a8165b41a60c624b all runs: OK false negative chance: 0.000 # git bisect good bf897d2626abe4559953342e2f7dda05d034c8c7 Bisecting: 1666 revisions left to test after this (roughly 11 steps) [fb5bc347311b1d78dc608c91c2d68327b0a1d1d4] Merge tag 'loongarch-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson testing commit fb5bc347311b1d78dc608c91c2d68327b0a1d1d4 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 7c7140746b82340a227d51206720a5d20dfebeb5ca9d15aa5f254001c7e1cba0 all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] # git bisect bad fb5bc347311b1d78dc608c91c2d68327b0a1d1d4 Bisecting: 803 revisions left to test after this (roughly 10 steps) [c6006b8ca14dcc604567be99fc4863e6e11ab6e3] Merge tag 'usb-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb testing commit c6006b8ca14dcc604567be99fc4863e6e11ab6e3 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 50f8f560d6798eab02e24a5dc4e5392d390bfbfef0b3c18ad3e2b1c9159c8ee9 all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] # git bisect bad c6006b8ca14dcc604567be99fc4863e6e11ab6e3 Bisecting: 411 revisions left to test after this (roughly 9 steps) [908057d185a41560a55890afa69c9676fc63e55c] Merge tag 'v6.18-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 testing commit 908057d185a41560a55890afa69c9676fc63e55c gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 1a35b0633c25f423f8d4cfd1779dc241ac065b61cf7e39ef3b3343653b36c532 all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] # git bisect bad 908057d185a41560a55890afa69c9676fc63e55c Bisecting: 210 revisions left to test after this (roughly 8 steps) [50ac57c3b156e893e34310f0be340a130f36f6db] Merge tag 'x86_tdx_for_6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip testing commit 50ac57c3b156e893e34310f0be340a130f36f6db gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 9fc727fc44b05639f3f7cb42941781dd702189a5129734b1f848be31b3ce611a all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] # git bisect bad 50ac57c3b156e893e34310f0be340a130f36f6db Bisecting: 117 revisions left to test after this (roughly 7 steps) [10fd0285305d0b48e8a3bf15d4f17fc4f3d68cb6] Merge branch kvm-arm64/selftests-6.18 into kvmarm-master/next testing commit 10fd0285305d0b48e8a3bf15d4f17fc4f3d68cb6 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 837e433f37ccd368039716a5cb30be3b42516203515ca33026ef5d790ca573d9 all runs: OK false negative chance: 0.000 # git bisect good 10fd0285305d0b48e8a3bf15d4f17fc4f3d68cb6 Bisecting: 56 revisions left to test after this (roughly 6 steps) [924ccf1d093a0c688eba9da1adff9a290d7bd7d8] Merge tag 'kvm-riscv-6.18-1' of https://github.com/kvm-riscv/linux into HEAD testing commit 924ccf1d093a0c688eba9da1adff9a290d7bd7d8 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: d8624a86738388d4613399f6a6ebd9ac6d9b348fd0249495b4c4f45fde05f994 all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] # git bisect bad 924ccf1d093a0c688eba9da1adff9a290d7bd7d8 Bisecting: 30 revisions left to test after this (roughly 5 steps) [8cbb0df2945a0fcb1f0b4384e65f13ec727baef4] Merge tag 'kvmarm-fixes-6.17-2' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD testing commit 8cbb0df2945a0fcb1f0b4384e65f13ec727baef4 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: d1f25b2396d0ad32bac2f8446606acab596dd203819dadfde74db90d75854de0 all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] # git bisect bad 8cbb0df2945a0fcb1f0b4384e65f13ec727baef4 Bisecting: 14 revisions left to test after this (roughly 4 steps) [a3522ac71f5e1c1a9bacee46663d6e83efb9c325] KVM: x86/mmu: Enforce guest_memfd's max order when recovering hugepages testing commit a3522ac71f5e1c1a9bacee46663d6e83efb9c325 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 3a125ea4215b217b66dfc6b033a618ffa9e7f0df8857393a78434db70f81454e all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] # git bisect bad a3522ac71f5e1c1a9bacee46663d6e83efb9c325 Bisecting: 7 revisions left to test after this (roughly 3 steps) [923310be23b275f730e8869abc783db6296fc043] KVM: Rename kvm_slot_can_be_private() to kvm_slot_has_gmem() testing commit 923310be23b275f730e8869abc783db6296fc043 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: c58225b32698bc281254c92d7db438985222dd040256751142391865971c32ec all runs: OK false negative chance: 0.000 # git bisect good 923310be23b275f730e8869abc783db6296fc043 Bisecting: 3 revisions left to test after this (roughly 2 steps) [a12578e1477cbfb547256ed8dee6d5142a59cdcd] KVM: guest_memfd: Add plumbing to host to map guest_memfd pages testing commit a12578e1477cbfb547256ed8dee6d5142a59cdcd gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: b9e94e37f0cbcb47f6a8452f35f6461011d440c16952b7c3d7f6a32dab84e028 all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] # git bisect bad a12578e1477cbfb547256ed8dee6d5142a59cdcd Bisecting: 1 revision left to test after this (roughly 1 step) [68d189938709a5918d7308eb922c30bcbf16ebb9] KVM: Fix comment that refers to kvm uapi header path testing commit 68d189938709a5918d7308eb922c30bcbf16ebb9 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 4a52de78afe6af115f88650d0f1841931f35c8483d00bde18e6d2fb1473b72c1 all runs: OK false negative chance: 0.000 # git bisect good 68d189938709a5918d7308eb922c30bcbf16ebb9 Bisecting: 0 revisions left to test after this (roughly 0 steps) [d1e54dd08f163a9021433020d16a8f8f70ddc41c] KVM: x86: Enable KVM_GUEST_MEMFD for all 64-bit builds testing commit d1e54dd08f163a9021433020d16a8f8f70ddc41c gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: f19ccb479403a6f8d7cfee58ebf2b4195e05a277607ef074ad4ab593900df86d all runs: crashed: KASAN: slab-use-after-free Write in kvm_gmem_release representative crash: KASAN: slab-use-after-free Write in kvm_gmem_release, types: [KASAN-USE-AFTER-FREE-WRITE] # git bisect bad d1e54dd08f163a9021433020d16a8f8f70ddc41c d1e54dd08f163a9021433020d16a8f8f70ddc41c is the first bad commit commit d1e54dd08f163a9021433020d16a8f8f70ddc41c Author: Fuad Tabba Date: Tue Jul 29 15:54:40 2025 -0700 KVM: x86: Enable KVM_GUEST_MEMFD for all 64-bit builds Enable KVM_GUEST_MEMFD for all KVM x86 64-bit builds, i.e. for "default" VM types when running on 64-bit KVM. This will allow using guest_memfd to back non-private memory for all VM shapes, by supporting mmap() on guest_memfd. Opportunistically clean up various conditionals that become tautologies once x86 selects KVM_GUEST_MEMFD more broadly. Specifically, because SW protected VMs, SEV, and TDX are all 64-bit only, private memory no longer needs to take explicit dependencies on KVM_GUEST_MEMFD, because it is effectively a prerequisite. Suggested-by: Sean Christopherson Signed-off-by: Fuad Tabba Reviewed-by: Xiaoyao Li Reviewed-by: David Hildenbrand Signed-off-by: Sean Christopherson Message-ID: <20250729225455.670324-10-seanjc@google.com> Signed-off-by: Paolo Bonzini arch/x86/include/asm/kvm_host.h | 4 +--- arch/x86/kvm/Kconfig | 12 ++++-------- include/linux/kvm_host.h | 9 ++------- virt/kvm/kvm_main.c | 4 ++-- 4 files changed, 9 insertions(+), 20 deletions(-) accumulated error probability: 0.00 culprit signature: f19ccb479403a6f8d7cfee58ebf2b4195e05a277607ef074ad4ab593900df86d parent signature: 4a52de78afe6af115f88650d0f1841931f35c8483d00bde18e6d2fb1473b72c1 revisions tested: 22, total time: 9h48m3.34731019s (build: 6h27m33.993850536s, test: 2h36m57.585507425s) first bad commit: d1e54dd08f163a9021433020d16a8f8f70ddc41c KVM: x86: Enable KVM_GUEST_MEMFD for all 64-bit builds recipients (to): ["david@redhat.com" "pbonzini@redhat.com" "seanjc@google.com" "tabba@google.com" "xiaoyao.li@intel.com"] recipients (cc): [] crash: KASAN: slab-use-after-free Write in kvm_gmem_release ================================================================== BUG: KASAN: slab-use-after-free in kvm_gmem_release+0x179/0x350 virt/kvm/guest_memfd.c:276 Write of size 8 at addr ffff88811e95cd08 by task syz.2.17/3862 CPU: 1 UID: 0 PID: 3862 Comm: syz.2.17 Not tainted syzkaller #0 PREEMPT(none) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0xf4/0x170 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 kvm_gmem_release+0x179/0x350 virt/kvm/guest_memfd.c:276 __fput+0x30b/0x7a0 fs/file_table.c:468 task_work_run+0x149/0x1e0 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xbf/0xd0 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x181/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb383f9efc9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff69fbf7c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fb3841f7da0 RCX: 00007fb383f9efc9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fb3841f7da0 R08: 0000000000000000 R09: 0000000469fbfabf R10: 00007fb3841f7cb0 R11: 0000000000000246 R12: 000000000001233f R13: 00007fff69fbf8c0 R14: ffffffffffffffff R15: 00007fff69fbf8e0 Allocated by task 3863: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x220/0x410 mm/slub.c:4396 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] kvm_set_memory_region+0x54f/0x9c0 virt/kvm/kvm_main.c:2095 kvm_vm_ioctl_set_memory_region+0x51/0xa0 virt/kvm/kvm_main.c:2145 kvm_vm_ioctl+0x302/0x900 virt/kvm/kvm_main.c:5189 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xae/0x100 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x8f/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 3863: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kfree+0x174/0x3e0 mm/slub.c:4879 kvm_set_memory_region+0x754/0x9c0 virt/kvm/kvm_main.c:2121 kvm_vm_ioctl_set_memory_region+0x51/0xa0 virt/kvm/kvm_main.c:2145 kvm_vm_ioctl+0x302/0x900 virt/kvm/kvm_main.c:5189 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xae/0x100 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x8f/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88811e95cc00 which belongs to the cache kmalloc-cg-512 of size 512 The buggy address is located 264 bytes inside of freed 512-byte region [ffff88811e95cc00, ffff88811e95ce00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11e95c head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88811b08a901 flags: 0x200000000000040(head|node=0|zone=2) page_type: f5(slab) raw: 0200000000000040 ffff88810004b140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080100010 00000000f5000000 ffff88811b08a901 head: 0200000000000040 ffff88810004b140 dead000000000100 dead000000000122 head: 0000000000000000 0000000080100010 00000000f5000000 ffff88811b08a901 head: 0200000000000002 ffffea00047a5701 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2747, tgid 2747 (dhcpcd-run-hook), ts 22234772235, free_ts 13339315646 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x168/0x1a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x290d/0x29e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x26b/0x460 mm/page_alloc.c:5148 alloc_pages_mpol+0xcb/0x270 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2487 [inline] allocate_slab+0x8a/0x320 mm/slub.c:2655 new_slab mm/slub.c:2709 [inline] ___slab_alloc+0x9c6/0x10a0 mm/slub.c:3891 __slab_alloc mm/slub.c:3981 [inline] __slab_alloc_node mm/slub.c:4056 [inline] slab_alloc_node mm/slub.c:4217 [inline] __kmalloc_cache_noprof+0x27c/0x410 mm/slub.c:4391 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] alloc_pipe_info+0xc9/0x3f0 fs/pipe.c:798 get_pipe_inode fs/pipe.c:894 [inline] create_pipe_files+0x88/0x730 fs/pipe.c:926 __do_pipe_flags+0x2c/0x1c0 fs/pipe.c:988 do_pipe2+0xa1/0x150 fs/pipe.c:1036 __do_sys_pipe2 fs/pipe.c:1054 [inline] __se_sys_pipe2 fs/pipe.c:1052 [inline] __x64_sys_pipe2+0x55/0x70 fs/pipe.c:1052 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x8f/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 2440 tgid 2440 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xa32/0xba0 mm/page_alloc.c:2895 __slab_free+0x2c4/0x370 mm/slub.c:4591 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] __kmalloc_cache_noprof+0x1ad/0x410 mm/slub.c:4391 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] kernfs_fop_open+0x349/0xab0 fs/kernfs/file.c:623 do_dentry_open+0x731/0x1060 fs/open.c:965 vfs_open+0x36/0x2b0 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x23e3/0x2bb0 fs/namei.c:4046 do_filp_open+0x1e4/0x3c0 fs/namei.c:4073 do_sys_openat2+0xfa/0x180 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0xf3/0x120 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x8f/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88811e95cc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811e95cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88811e95cd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811e95cd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811e95ce00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================