ci2 starts bisection 2026-10-31 20:28:39.042318633 +0000 UTC m=+42744.945772140 bisecting fixing commit since 6436c12a2ced865a3382b867e3882d08c2d2bf8d building syzkaller on 5d63f80b763910b40ae04a96c13dc75d621bea67 ensuring issue is reproducible on original commit 6436c12a2ced865a3382b867e3882d08c2d2bf8d testing commit 6436c12a2ced865a3382b867e3882d08c2d2bf8d gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: 379dfca986e0640433d65ac26301bc1f71b5f91e0e943e4c260a60f56cd40ad6 run #0: crashed: WARNING: refcount bug in config_item_get run #1: crashed: WARNING: refcount bug in config_item_get run #2: crashed: WARNING: refcount bug in config_item_get run #3: crashed: KASAN: slab-use-after-free Write in config_item_get run #4: crashed: WARNING: refcount bug in config_item_get run #5: crashed: WARNING: refcount bug in config_item_get run #6: crashed: WARNING: refcount bug in config_item_get run #7: crashed: WARNING: refcount bug in config_item_get run #8: crashed: WARNING: refcount bug in config_item_get run #9: crashed: WARNING: refcount bug in config_item_get run #10: crashed: WARNING: refcount bug in config_item_get run #11: crashed: WARNING: refcount bug in config_item_get run #12: crashed: WARNING: refcount bug in config_item_get run #13: crashed: WARNING: refcount bug in config_item_get run #14: crashed: WARNING: refcount bug in config_item_get run #15: crashed: WARNING: refcount bug in config_item_get run #16: crashed: WARNING: refcount bug in config_item_get run #17: crashed: WARNING: refcount bug in config_item_get run #18: crashed: WARNING: refcount bug in config_item_get run #19: crashed: KASAN: slab-use-after-free Write in config_item_get representative crash: WARNING: refcount bug in config_item_get, types: [REFCOUNT_WARNING] check whether we can drop unnecessary instrumentation disabling configs for [atomic_sleep hang memleak ubsan kasan locking], they are not needed testing commit 6436c12a2ced865a3382b867e3882d08c2d2bf8d gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: 0e748abb5bb12e66a41a1d3043eb93bd9c0818c0b1fde975820aab88bd05bdd0 all runs: crashed: WARNING: refcount bug in config_item_get representative crash: WARNING: refcount bug in config_item_get, types: [REFCOUNT_WARNING] the bug reproduces without the instrumentation disabling configs for [kasan locking atomic_sleep hang memleak ubsan], they are not needed kconfig minimization: base=3916 full=7804 leaves diff=2160 split chunks (needed=false): <2160> split chunk #0 of len 2160 into 5 parts testing without sub-chunk 1/5 disabling configs for [kasan locking atomic_sleep hang memleak ubsan], they are not needed testing commit 6436c12a2ced865a3382b867e3882d08c2d2bf8d gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: 4075851891c4f64f76fc6d8a06070898b9773a8dc2c93888ffb0e7fe7afd00a3 all runs: crashed: WARNING: refcount bug in config_item_get representative crash: WARNING: refcount bug in config_item_get, types: [REFCOUNT_WARNING] the chunk can be dropped testing without sub-chunk 2/5 disabling configs for [kasan locking atomic_sleep hang memleak ubsan], they are not needed testing commit 6436c12a2ced865a3382b867e3882d08c2d2bf8d gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: 8420d66c9978eb2aebacfbf3f348d4c390becef99551f9082d0c76cd0331b49d all runs: crashed: WARNING: refcount bug in config_item_get representative crash: WARNING: refcount bug in config_item_get, types: [REFCOUNT_WARNING] the chunk can be dropped testing without sub-chunk 3/5 disabling configs for [hang memleak ubsan kasan locking atomic_sleep], they are not needed testing commit 6436c12a2ced865a3382b867e3882d08c2d2bf8d gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: 9547d6fef14a371db9a9a1215400535e8aa982ae9d8f7d0f9f697cfe5e118512 all runs: crashed: WARNING: refcount bug in config_item_get representative crash: WARNING: refcount bug in config_item_get, types: [REFCOUNT_WARNING] the chunk can be dropped testing without sub-chunk 4/5 disabling configs for [kasan locking atomic_sleep hang memleak ubsan], they are not needed testing commit 6436c12a2ced865a3382b867e3882d08c2d2bf8d gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: 223f99bf197cc545f033da933fe358b6fea34e33661c572b9d7acfb49a5a32a9 all runs: crashed: WARNING: refcount bug in config_item_get representative crash: WARNING: refcount bug in config_item_get, types: [REFCOUNT_WARNING] the chunk can be dropped testing without sub-chunk 5/5 disabling configs for [hang memleak ubsan kasan locking atomic_sleep], they are not needed testing commit 6436c12a2ced865a3382b867e3882d08c2d2bf8d gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: bee237458e793663362e03236ec644ad9c9f9775acd92692f351c5951d0e7105 all runs: OK false negative chance: 0.000 minimized to 432 configs; suspects: [ARCH_ENABLE_MEMORY_HOTREMOVE ATM BCMA BLK_DEV_ZONED BPF_SYSCALL CARDBUS CFG80211 CFG80211_WEXT CMA COMMON_CLK CONTIG_ALLOC CRYPTO_842 CRYPTO_LZ4 CRYPTO_LZ4HC CRYPTO_LZO CRYPTO_ZSTD DVB_CORE EXTCON FB 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_AMD5536UDC USB_ATM 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_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_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 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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_MV_U3D USB_MV_UDC USB_NET2272 USB_NET2272_DMA 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_RNDIS_WLAN 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 VDPA_USER VETH VFIO VFIO_DEVICE_CDEV VFIO_PCI VFIO_PCI_CORE VFIO_PCI_INTX VFIO_PCI_MMAP VFIO_VIRQFD VGASTATE VHOST VHOST_CROSS_ENDIAN_LEGACY VHOST_IOTLB VHOST_NET VHOST_RING VHOST_TASK VHOST_VDPA VHOST_VSOCK 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_CMDLINE 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_NOMODESET 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 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_PRIV WEXT_PROC WIREGUARD WIRELESS WIRELESS_EXT WLAN WLAN_VENDOR_ADMTEK WLAN_VENDOR_SILABS X86_SGX X86_SGX_KVM X86_USER_SHADOW_STACK X86_X2APIC XARRAY_MULTI XDP_SOCKETS XDP_SOCKETS_DIAG XFRM_ESPINTCP XFRM_INTERFACE XFRM_IPCOMP XFRM_MIGRATE XFRM_OFFLOAD XFRM_STATISTICS XFRM_SUB_POLICY XFRM_USER_COMPAT XFS_DRAIN_INTENTS XFS_FS XFS_ONLINE_REPAIR XFS_ONLINE_SCRUB XFS_POSIX_ACL XFS_QUOTA XFS_RT XILLYBUS_CLASS XILLYUSB XOR_BLOCKS YENTA YENTA_ENE_TUNE YENTA_O2 YENTA_RICOH YENTA_TI YENTA_TOSHIBA ZBUD ZEROPLUS_FF ZLIB_DEFLATE ZONEFS_FS ZPOOL ZRAM ZRAM_DEF_COMP_LZORLE ZSMALLOC ZSTD_COMPRESS ZSWAP ZSWAP_COMPRESSOR_DEFAULT_LZO ZSWAP_DEFAULT_ON ZSWAP_ZPOOL_DEFAULT_ZBUD] disabling configs for [ubsan kasan locking atomic_sleep hang memleak], they are not needed testing current HEAD b5a1dc3ad4822c6edfb53429e9a3759c9b0ac2be testing commit b5a1dc3ad4822c6edfb53429e9a3759c9b0ac2be gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: 17170d5dd622d21fc27beae7243486f1019f4dd277eda6ed0381824aefc435b2 all runs: OK false negative chance: 0.000 # git bisect start b5a1dc3ad4822c6edfb53429e9a3759c9b0ac2be 6436c12a2ced865a3382b867e3882d08c2d2bf8d Bisecting: 2583 revisions left to test after this (roughly 11 steps) [593e64f64a20b25e4042c3ee863119eb7f991785] Bluetooth: hci_core: Fix race condition during device registration determine whether the revision contains the guilty commit revision 6436c12a2ced865a3382b867e3882d08c2d2bf8d crashed and is reachable testing commit 593e64f64a20b25e4042c3ee863119eb7f991785 gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: af5b56b89bec8a9d7e8fd0de867120f79289622a783c5134c9d5c7131ac18d5d all runs: crashed: WARNING: refcount bug in config_item_get representative crash: WARNING: refcount bug in config_item_get, types: [REFCOUNT_WARNING] # git bisect good 593e64f64a20b25e4042c3ee863119eb7f991785 Bisecting: 1291 revisions left to test after this (roughly 10 steps) [a5ce29550386f8799947c328faefe55dbaa4646e] drm/gud: don't keep a connector without a CRTC as connector_state determine whether the revision contains the guilty commit revision 6436c12a2ced865a3382b867e3882d08c2d2bf8d crashed and is reachable testing commit a5ce29550386f8799947c328faefe55dbaa4646e gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: 8fd91dc5752cdf844182d110fa0cd7854431f135efd3a091aeebb13d16177650 run #0: crashed: WARNING: refcount bug in config_item_get run #1: crashed: WARNING: refcount bug in config_item_get run #2: crashed: WARNING: refcount bug in config_item_get run #3: crashed: WARNING: refcount bug in config_item_get run #4: crashed: WARNING: refcount bug in config_item_get run #5: crashed: WARNING: refcount bug in config_item_get run #6: crashed: WARNING: refcount bug in config_item_get run #7: crashed: WARNING: refcount bug in config_item_get run #8: crashed: WARNING: refcount bug in config_item_get run #9: basic kernel testing failed: failed to copy binary to VM: failed to run ["ssh" "-p" "22" "-F" "/dev/null" "-o" "UserKnownHostsFile=/dev/null" "-o" "IdentitiesOnly=yes" "-o" "BatchMode=yes" "-o" "StrictHostKeyChecking=no" "-o" "ConnectTimeout=10" "root@10.128.1.191" "mkdir" "-p" "ci2-linux-6-6-kasan-bisect-job"]: exit status 255 representative crash: WARNING: refcount bug in config_item_get, types: [REFCOUNT_WARNING] # git bisect good a5ce29550386f8799947c328faefe55dbaa4646e Bisecting: 645 revisions left to test after this (roughly 9 steps) [724c8edbacf1259988829cb9967f751222121d8a] net/sched: cls_u32: validate offshift to prevent shift-out-of-bounds determine whether the revision contains the guilty commit revision a5ce29550386f8799947c328faefe55dbaa4646e crashed and is reachable testing commit 724c8edbacf1259988829cb9967f751222121d8a gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: eccdb6a4c9feb6a1dd9aaf5c1a1e8468d90e98d4c6017d5cf1826fb395a0ed47 all runs: crashed: WARNING: refcount bug in config_item_get representative crash: WARNING: refcount bug in config_item_get, types: [REFCOUNT_WARNING] # git bisect good 724c8edbacf1259988829cb9967f751222121d8a Bisecting: 322 revisions left to test after this (roughly 8 steps) [c422d5d53f135ea987f745773953a91f9fe30c3f] wifi: iwlwifi: pcie: null RX pointers after free determine whether the revision contains the guilty commit revision 724c8edbacf1259988829cb9967f751222121d8a crashed and is reachable testing commit c422d5d53f135ea987f745773953a91f9fe30c3f gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: 2df2b83840fc6afd7aa3a0b6cdb02629471515c1704c9fa50c4cb3f428f3833b all runs: crashed: WARNING: refcount bug in config_item_get representative crash: WARNING: refcount bug in config_item_get, types: [REFCOUNT_WARNING] # git bisect good c422d5d53f135ea987f745773953a91f9fe30c3f Bisecting: 161 revisions left to test after this (roughly 7 steps) [f561392afb44a8a42c54c1cfd3f33dace0b50537] Drivers: hv: Avoid infinite retry loop in init_vp_index() determine whether the revision contains the guilty commit revision 724c8edbacf1259988829cb9967f751222121d8a crashed and is reachable testing commit f561392afb44a8a42c54c1cfd3f33dace0b50537 gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: 7682ed1117983a7eb79d9f924f993fd23533bec91638efc6ae6ce4d6f7b5995d all runs: OK false negative chance: 0.000 # git bisect bad f561392afb44a8a42c54c1cfd3f33dace0b50537 Bisecting: 80 revisions left to test after this (roughly 6 steps) [880712b6f48103ba3a04b154ff076d45fe86dcec] tracing: Undo the registration when enabling the histogram trigger fails determine whether the revision contains the guilty commit revision c422d5d53f135ea987f745773953a91f9fe30c3f crashed and is reachable testing commit 880712b6f48103ba3a04b154ff076d45fe86dcec gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: a67ba3bdc196c43d1095c831d03e83577cc143cbd7b67945599eefba7ee68dd4 all runs: crashed: WARNING: refcount bug in config_item_get representative crash: WARNING: refcount bug in config_item_get, types: [REFCOUNT_WARNING] # git bisect good 880712b6f48103ba3a04b154ff076d45fe86dcec Bisecting: 40 revisions left to test after this (roughly 5 steps) [4c85e4a0e8b07d0241fed6c2a4522de1bcc09fd2] net: plumb extack in __dev_change_net_namespace() determine whether the revision contains the guilty commit revision 724c8edbacf1259988829cb9967f751222121d8a crashed and is reachable testing commit 4c85e4a0e8b07d0241fed6c2a4522de1bcc09fd2 gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: 2f0e5936929be61366b9ec89a3f69a297d6f2fd2f49c07933c3ed2a2ebdeec3b all runs: OK false negative chance: 0.000 # git bisect bad 4c85e4a0e8b07d0241fed6c2a4522de1bcc09fd2 Bisecting: 19 revisions left to test after this (roughly 4 steps) [914c7cc2e3d10dddd3c5529cbe56557c9e01702a] vhost-vdpa: protect config_ctx from being freed under the config callback determine whether the revision contains the guilty commit revision 880712b6f48103ba3a04b154ff076d45fe86dcec crashed and is reachable testing commit 914c7cc2e3d10dddd3c5529cbe56557c9e01702a gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: 058826a6f3379cfb2b34f1501cc433b94306502d314a4c39b44784137c636076 all runs: OK false negative chance: 0.000 # git bisect bad 914c7cc2e3d10dddd3c5529cbe56557c9e01702a Bisecting: 9 revisions left to test after this (roughly 3 steps) [09c30547da2c45bb79f7d3adffc860af332c2d42] net: stmmac: fix TX descriptor availability check for TSO traffic determine whether the revision contains the guilty commit revision 593e64f64a20b25e4042c3ee863119eb7f991785 crashed and is reachable testing commit 09c30547da2c45bb79f7d3adffc860af332c2d42 gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: f2fc404d293e973973d9cc67b432333db85aa310aaebcf5971c82d92e49984a2 all runs: OK false negative chance: 0.000 # git bisect bad 09c30547da2c45bb79f7d3adffc860af332c2d42 Bisecting: 4 revisions left to test after this (roughly 2 steps) [0c1a966bc047af2801a70b8eb13f9df5d7ab925f] reboot: fix cad_pid use-after-free race determine whether the revision contains the guilty commit revision 593e64f64a20b25e4042c3ee863119eb7f991785 crashed and is reachable testing commit 0c1a966bc047af2801a70b8eb13f9df5d7ab925f gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: 37479560ba635b75dbfff5c5048f85133a00280feb2784952d9979358805b632 all runs: crashed: WARNING: refcount bug in config_item_get representative crash: WARNING: refcount bug in config_item_get, types: [REFCOUNT_WARNING] # git bisect good 0c1a966bc047af2801a70b8eb13f9df5d7ab925f Bisecting: 2 revisions left to test after this (roughly 1 step) [db6d0b2f307f01c458e76f7ac16b74b773e85584] path: add cleanup helper determine whether the revision contains the guilty commit revision 593e64f64a20b25e4042c3ee863119eb7f991785 crashed and is reachable testing commit db6d0b2f307f01c458e76f7ac16b74b773e85584 gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: 49f7f3cf700f90181875c3a09902f5d6eb03d9a52c139c1dd0216da1bb37df4c all runs: OK false negative chance: 0.000 # git bisect bad db6d0b2f307f01c458e76f7ac16b74b773e85584 Bisecting: 0 revisions left to test after this (roughly 0 steps) [b315d865660766d45ecdbf7433a4e3d36a554b3b] configfs: unhash the dentry before dropping the item in rmdir determine whether the revision contains the guilty commit revision c422d5d53f135ea987f745773953a91f9fe30c3f crashed and is reachable testing commit b315d865660766d45ecdbf7433a4e3d36a554b3b gcc compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 kernel signature: a3f6fb84b2734e9ebaf14b46b02148b562084be118cd6d2c1b131a089bb62477 all runs: OK false negative chance: 0.000 # git bisect bad b315d865660766d45ecdbf7433a4e3d36a554b3b b315d865660766d45ecdbf7433a4e3d36a554b3b is the first bad commit commit b315d865660766d45ecdbf7433a4e3d36a554b3b Author: Vasileios Almpanis Date: Thu Jul 30 11:30:25 2026 +0200 configfs: unhash the dentry before dropping the item in rmdir [ Upstream commit f06c2d26d1999d37e93299db0ecead04ca7d0b9f ] configfs_get_config_item() treats a hashed dentry as proof that sd->s_element is a live config_item. configfs_rmdir() breaks that: simple_rmdir() leaves the dentry hashed, the last reference to the item is dropped right after, and the dentry is only unhashed by d_delete() once ->rmdir() has returned. configfs_symlink() resolves its target holding no lock on it, so get_target() can land in that window: BUG: KASAN: slab-use-after-free in config_item_get+0x26/0x90 get_target fs/configfs/symlink.c:128 [inline] configfs_symlink+0x4ab/0x1030 fs/configfs/symlink.c:185 Unhash in configfs_remove_dir(), while the item is still guaranteed to be there. A reference obtained just before that stays harmless, as create_link() rechecks CONFIGFS_USET_DROPPING, already set by configfs_detach_prep(). Both configfs_unregister_subsystem() paths d_drop() after detaching, so this only makes rmdir match them. Reported-by: syzbot+6b16e3d085833cbf3e25@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=6b16e3d085833cbf3e25 Fixes: 7063fbf22611 ("[PATCH] configfs: User-driven configuration filesystem") Cc: stable@vger.kernel.org Signed-off-by: Vasileios Almpanis Tested-by: Breno Leitao Reviewed-by: Breno Leitao Link: https://patch.msgid.link/20260730093435.195441-3-vasilisalmpanis@gmail.com Signed-off-by: Breno Leitao Signed-off-by: Sasha Levin fs/configfs/dir.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) accumulated error probability: 0.00 culprit signature: a3f6fb84b2734e9ebaf14b46b02148b562084be118cd6d2c1b131a089bb62477 parent signature: 37479560ba635b75dbfff5c5048f85133a00280feb2784952d9979358805b632 revisions tested: 20, total time: 5h21m11.575481155s (build: 2h9m14.621955695s, test: 2h44m28.782609911s) first good commit: b315d865660766d45ecdbf7433a4e3d36a554b3b configfs: unhash the dentry before dropping the item in rmdir recipients (to): ["leitao@debian.org" "sashal@kernel.org" "vasilisalmpanis@gmail.com"] recipients (cc): []