ci starts bisection 2025-09-25 06:20:18.690756376 +0000 UTC m=+123436.503763926 bisecting cause commit starting from b5a4da2c459f79a2c87c867398f1c0c315779781 building syzkaller on 0abd06914a0618dff2f4b80e8d3c0bfb50121eb1 ensuring issue is reproducible on original commit b5a4da2c459f79a2c87c867398f1c0c315779781 testing commit b5a4da2c459f79a2c87c867398f1c0c315779781 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: e1e9c7c34fbeab6ba1b7f60d30cbfa62b1ea407f77ad25365d150d0f1bfbdd97 all runs: crashed: general protection fault in exfat_utf16_to_nls representative crash: general protection fault in exfat_utf16_to_nls, types: [DoS] check whether we can drop unnecessary instrumentation disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep hang], they are not needed testing commit b5a4da2c459f79a2c87c867398f1c0c315779781 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 37f393807db3cbeb9d8dd86b7dcfb51d6191e1268dcd27cee3ab49829d4729b8 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls representative crash: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls, types: [NULL-POINTER-DEREFERENCE] the bug reproduces without the instrumentation disabling configs for [ubsan bug_or_warning kasan locking atomic_sleep hang memleak], they are not needed kconfig minimization: base=4099 full=8527 leaves diff=2182 split chunks (needed=false): <2182> split chunk #0 of len 2182 into 5 parts testing without sub-chunk 1/5 disabling configs for [hang memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed testing commit b5a4da2c459f79a2c87c867398f1c0c315779781 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 26f6ef0e4c89651b57084441809d737796741dc1db62d9ee217cd606b10a47a1 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls representative crash: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls, types: [NULL-POINTER-DEREFERENCE] the chunk can be dropped testing without sub-chunk 2/5 disabling configs for [hang memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed testing commit b5a4da2c459f79a2c87c867398f1c0c315779781 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: d5f19f1867a576161172d1ea0d3a4f929202e3025ac3e07fc875158e01ded692 all runs: OK false negative chance: 0.000 testing without sub-chunk 3/5 disabling configs for [atomic_sleep hang memleak ubsan bug_or_warning kasan locking], they are not needed testing commit b5a4da2c459f79a2c87c867398f1c0c315779781 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 41dba4171769a9ae16cc7c8f4916e265073862db9cf0509080285bcb3b478b42 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls representative crash: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls, types: [NULL-POINTER-DEREFERENCE] the chunk can be dropped testing without sub-chunk 4/5 disabling configs for [hang memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed testing commit b5a4da2c459f79a2c87c867398f1c0c315779781 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: aced8a9d297177caf3fd3c4b67247a13a61305cfd78cda1687040e54dfb3466d all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls representative crash: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls, types: [NULL-POINTER-DEREFERENCE] the chunk can be dropped testing without sub-chunk 5/5 disabling configs for [locking atomic_sleep hang memleak ubsan bug_or_warning kasan], they are not needed testing commit b5a4da2c459f79a2c87c867398f1c0c315779781 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: c800ec13c2c60ee132541d9a053169228896ea33ba746085042916da7de93952 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls representative crash: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls, types: [NULL-POINTER-DEREFERENCE] the chunk can be dropped minimized to 437 configs; suspects: [6LOWPAN ARCH_ENABLE_MEMORY_HOTREMOVE ASUS_WMI BLK_DEV_ZONED CHARGER_BQ24190 CMA COMMON_CLK DAX DLM DMA_ENGINE_RAID DM_AUDIT DM_BIO_PRISON DM_BUFIO DM_CACHE DM_CACHE_SMQ DM_CLONE DM_CRYPT DM_FLAKEY DM_INTEGRITY DM_MULTIPATH DM_MULTIPATH_QL DM_MULTIPATH_ST DM_PERSISTENT_DATA DM_RAID DM_SNAPSHOT DM_THIN_PROVISIONING DM_UEVENT DM_VERITY DM_VERITY_FEC DM_WRITECACHE DM_ZONED DRAGONRISE_FF DRM DRM_AUX_BRIDGE DRM_BOCHS DRM_BRIDGE DRM_BUDDY DRM_CIRRUS_QEMU DRM_CLIENT DRM_CLIENT_DEFAULT_FBDEV DRM_CLIENT_LIB DRM_CLIENT_SELECTION DRM_CLIENT_SETUP DRM_DEBUG_MM DRM_DISPLAY_DP_AUX_BUS DRM_DISPLAY_DP_HELPER DRM_DISPLAY_DSC_HELPER DRM_DISPLAY_HDCP_HELPER DRM_DISPLAY_HDMI_HELPER DRM_DISPLAY_HELPER DRM_FBDEV_EMULATION DRM_GEM_SHMEM_HELPER DRM_GM12U320 DRM_GUD DRM_I915 DRM_I915_CAPTURE_ERROR DRM_I915_COMPRESS_ERROR DRM_I915_USERPTR DRM_KMS_HELPER DRM_MIPI_DSI DRM_PANEL DRM_PANEL_BRIDGE DRM_PANEL_EDP DRM_PANEL_ORIENTATION_QUIRKS DRM_SIMPLEDRM DRM_SYSFB_HELPER DRM_TTM DRM_TTM_HELPER DRM_UDL DRM_VGEM DRM_VIRTIO_GPU DRM_VIRTIO_GPU_KMS DRM_VKMS DRM_VMWGFX DUMMY DVB_AF9013 DVB_AF9033 DVB_AS102 DVB_AS102_FE DVB_B2C2_FLEXCOP DVB_B2C2_FLEXCOP_USB DVB_CORE DVB_DIB3000MB DVB_DIB3000MC DVB_EC100 DVB_GP8PSK_FE DVB_RTL2830 DVB_RTL2832 DVB_RTL2832_SDR DVB_TEST_DRIVERS DVB_TTUSB_BUDGET DVB_TTUSB_DEC DVB_USB DVB_USB_A800 DVB_USB_AF9005 DVB_USB_AF9005_REMOTE DVB_USB_AF9015 DVB_USB_AF9035 DVB_USB_ANYSEE DVB_USB_AU6610 DVB_USB_AZ6007 DVB_USB_AZ6027 DVB_USB_CE6230 DVB_USB_CINERGY_T2 DVB_USB_CXUSB DVB_USB_CXUSB_ANALOG DVB_USB_DIB0700 DVB_USB_DIB3000MC DVB_USB_DIBUSB_MB DVB_USB_DIBUSB_MC DVB_USB_DIGITV DVB_USB_DTT200U DVB_USB_DTV5100 DVB_USB_DVBSKY DVB_USB_DW2102 DVB_USB_EC168 DVB_USB_GL861 DVB_USB_GP8PSK DVB_USB_LME2510 DVB_USB_M920X DVB_USB_MXL111SF DVB_USB_NOVA_T_USB2 DVB_USB_OPERA1 DVB_USB_PCTV452E DVB_USB_RTL28XXU DVB_USB_TECHNISAT_USB2 DVB_USB_TTUSB2 DVB_USB_UMT_010 DVB_USB_V2 DVB_USB_VP702X DVB_USB_VP7045 DVB_USB_ZD1301 DVB_VIDTV DVB_ZL10353 ECRYPT_FS ECRYPT_FS_MESSAGING EDAC EFS_FS ENCRYPTED_KEYS EPROBE_EVENTS EQUALIZER EROFS_FS EROFS_FS_POSIX_ACL EROFS_FS_SECURITY EROFS_FS_XATTR EROFS_FS_ZIP EVM EVM_ADD_XATTRS EVM_ATTR_FSUUID EXFAT_FS EXPORTFS_BLOCK_OPS EXT3_FS EXT3_FS_POSIX_ACL EXT3_FS_SECURITY EXTCON EXTCON_INTEL_CHT_WC EXTCON_PTN5150 EXTCON_USBC_TUSB320 F2FS_CHECK_FS F2FS_FAULT_INJECTION F2FS_FS F2FS_FS_COMPRESSION F2FS_FS_LZ4 F2FS_FS_LZ4HC F2FS_FS_LZO F2FS_FS_LZORLE F2FS_FS_POSIX_ACL F2FS_FS_SECURITY F2FS_FS_XATTR F2FS_FS_ZSTD F2FS_STAT_FS FANOTIFY FANOTIFY_ACCESS_PERMISSIONS FB FB_CFB_COPYAREA FB_CFB_FILLRECT FB_CFB_IMAGEBLIT FB_CORE FB_DEFERRED_IO FB_DEVICE FB_IOMEM_FOPS FB_IOMEM_HELPERS FB_NOTIFY FB_SYSMEM_FOPS FB_SYSMEM_HELPERS FB_SYSMEM_HELPERS_DEFERRED FB_SYS_COPYAREA FB_SYS_FILLRECT FB_SYS_IMAGEBLIT FB_TILEBLITTING FB_VESA FB_VGA16 FB_VIRTUAL FDDI FIREWIRE FIREWIRE_NET FIREWIRE_OHCI FIREWIRE_SBP2 FONT_8x16 FONT_8x8 FONT_SUPPORT FRAMEBUFFER_CONSOLE FRAMEBUFFER_CONSOLE_DETECT_PRIMARY FRAMEBUFFER_CONSOLE_ROTATION FS_DAX FS_DAX_PMD FS_ENCRYPTION FS_ENCRYPTION_ALGS FS_STACK FS_VERITY FS_VERITY_BUILTIN_SIGNATURES FTL FUSE_DAX FUSE_FS FW_LOADER_COMPRESS FW_LOADER_PAGED_BUF FW_LOADER_SYSFS FW_LOADER_USER_HELPER FW_LOADER_USER_HELPER_FALLBACK GACT_PROB GARP GENDWARFKSYMS GENERIC_IRQ_ENTRY GENERIC_PHY GENERIC_SYSCALL GET_FREE_REGION GFS2_FS GFS2_FS_LOCKING_DLM GNSS GNSS_USB GOOGLE_COREBOOT_TABLE GOOGLE_FIRMWARE GOOGLE_MEMCONSOLE GOOGLE_MEMCONSOLE_COREBOOT GOOGLE_VPD GPIOLIB GPIOLIB_IRQCHIP GPIOLIB_LEGACY GPIO_ACPI GPIO_DLN2 GPIO_LJCA GPIO_VIPERBOARD GREENASIA_FF GREYBUS GREYBUS_BRIDGED_PHY GREYBUS_ES2 GREYBUS_HID GREYBUS_USB GROUP_SCHED_BANDWIDTH GTP GUEST_PERF_EVENTS HAS_LTO_CLANG HAVE_ARCH_KSTACK_ERASE HAVE_ARCH_NODE_DEV_GROUP HAVE_ARCH_USERFAULTFD_MINOR HAVE_ARCH_USERFAULTFD_WP HAVE_BOOTMEM_INFO_NODE HAVE_CLK_PREPARE HAVE_GENERIC_TIF_BITS HAVE_KVM_CPU_RELAX_INTERCEPT HAVE_KVM_DIRTY_RING HAVE_KVM_DIRTY_RING_ACQ_REL HAVE_KVM_DIRTY_RING_TSO HAVE_KVM_IRQCHIP HAVE_KVM_IRQ_BYPASS HAVE_KVM_IRQ_ROUTING HAVE_KVM_MSI HAVE_KVM_NO_POLL HAVE_KVM_PFNCACHE HAVE_KVM_PM_NOTIFIER HAVE_KVM_READONLY_MEM HAVE_SCHED_AVG_IRQ HDLC HDLC_CISCO HDLC_FR HDLC_PPP HDLC_RAW HDLC_RAW_ETH HDLC_X25 HDMI HFSPLUS_FS HFS_FS HID_ACCUTOUCH HID_ACRUX HID_ACRUX_FF HID_ALPS HID_APPLEIR HID_ASUS HID_AUREAL HID_BATTERY_STRENGTH HID_BETOP_FF HID_BIGBEN_FF HID_CMEDIA HID_CORSAIR HID_COUGAR HID_CP2112 HID_CREATIVE_SB0540 HID_DRAGONRISE HID_ELAN HID_ELECOM HID_ELO HID_EMS_FF HID_EVISION HID_FT260 HID_GEMBIRD HID_GFRM HID_GLORIOUS HID_GOOGLE_STADIA_FF HID_GREENASIA HID_GT683R HID_HOLTEK HID_ICADE HID_JABRA HID_KEYTOUCH HID_KYE HID_LCPOWER HID_LED HID_LENOVO HID_LETSKETCH HID_LOGITECH HID_LOGITECH_DJ HID_LOGITECH_HIDPP HID_MACALLY HID_MAGICMOUSE HID_MALTRON HID_MAYFLASH HID_MCP2200 HID_MCP2221 HID_MEGAWORLD_FF HID_MULTITOUCH HID_NTI HID_ORTEK HID_PENMOUNT HID_PICOLCD HID_PICOLCD_BACKLIGHT HID_PICOLCD_CIR HID_PICOLCD_FB HID_PICOLCD_LCD HID_PICOLCD_LEDS HID_PLANTRONICS HID_PRIMAX HID_PRODIKEYS HID_PXRC HID_RAZER HID_RETRODE HID_RMI HID_ROCCAT HID_SAITEK HID_SEMITEK HID_SENSOR_ACCEL_3D HID_SENSOR_ALS HID_SENSOR_CUSTOM_INTEL_HINGE HID_SENSOR_CUSTOM_SENSOR HID_SENSOR_DEVICE_ROTATION HID_SENSOR_GYRO_3D HID_SENSOR_HUB HID_SENSOR_HUMIDITY HID_SENSOR_IIO_COMMON HID_SENSOR_IIO_TRIGGER HID_SENSOR_INCLINOMETER_3D HID_SENSOR_MAGNETOMETER_3D HID_SENSOR_PRESS HID_SENSOR_PROX HID_SENSOR_TEMP HID_SIGMAMICRO HID_SPEEDLINK HID_STEELSERIES HID_THINGM HID_TIVO HID_TOPRE HID_TWINHAN HID_U2FZERO HID_UCLOGIC HID_UDRAW_PS3 HID_VIEWSONIC HID_VIVALDI HID_VIVALDI_COMMON HID_VRC2 HID_WACOM HID_WALTOP HID_WIIMOTE HID_XIAOMI HID_XINMO HID_ZYDACRON HMM_MIRROR HOLTEK_FF HOTPLUG_PCI_PCIE HPET_MMAP HPET_MMAP_DEFAULT HPFS_FS I2C_ALGOBIT I2C_CHARDEV I2C_CP2615 I2C_DESIGNWARE_CORE I2C_DESIGNWARE_PLATFORM I2C_DIOLAN_U2C I2C_DLN2 I2C_HID_ACPI I2C_HID_CORE I2C_HID_OF I2C_LJCA I2C_MUX I2C_MUX_REG I2C_ROBOTFUZZ_OSIF I2C_SI4713 I2C_SLAVE I2C_SLAVE_EEPROM I2C_TINY_USB I2C_VIPERBOARD IEEE802154 IEEE802154_6LOWPAN IEEE802154_ATUSB IEEE802154_DRIVERS IEEE802154_HWSIM IEEE802154_NL802154_EXPERIMENTAL IEEE802154_SOCKET IFB IIO IIO_BUFFER IIO_KFIFO_BUF IIO_TRIGGER IIO_TRIGGERED_BUFFER IKCONFIG IKCONFIG_PROC IMA IMA_APPRAISE IMA_APPRAISE_MODSIG IMA_DEFAULT_HASH_SHA256 IMA_LSM_RULES IMA_MEASURE_ASYMMETRIC_KEYS IMA_NG_TEMPLATE IMA_QUEUE_EARLY_BOOT_KEYS IMA_READ_POLICY IMA_WRITE_POLICY INET6_ESPINTCP INET6_ESP_OFFLOAD INET6_IPCOMP INET6_TUNNEL INET6_XFRM_TUNNEL INET_AH INET_DIAG INET_DIAG_DESTROY INET_ESP INET_ESPINTCP INET_ESP_OFFLOAD INET_IPCOMP INET_MPTCP_DIAG INET_RAW_DIAG INET_SCTP_DIAG INET_TCP_DIAG INET_UDP_DIAG INET_XFRM_TUNNEL INFINIBAND INFINIBAND_ADDR_TRANS INFINIBAND_ADDR_TRANS_CONFIGFS INFINIBAND_IPOIB INFINIBAND_IPOIB_CM INFINIBAND_IPOIB_DEBUG INFINIBAND_ISER INFINIBAND_ON_DEMAND_PAGING INFINIBAND_RTRS INFINIBAND_SRP INFINIBAND_USER_ACCESS INFINIBAND_USER_MAD INFINIBAND_USER_MEM INPUT_ATI_REMOTE2 INPUT_CM109 INPUT_IMS_PCU INPUT_JOYDEV INPUT_KEYSPAN_REMOTE INPUT_LEDS INPUT_MOUSEDEV INPUT_MOUSEDEV_PSAUX INPUT_POWERMATE INPUT_UINPUT INPUT_YEALINK INTEGRITY INTEGRITY_ASYMMETRIC_KEYS INTEGRITY_AUDIT INTEGRITY_SIGNATURE INTEGRITY_TRUSTED_KEYRING INTEL_CHTWC_INT33FE INTEL_IDMA64 INTEL_IOATDMA INTEL_IOMMU_DEFAULT_ON INTEL_IOMMU_SVM INTEL_ISHTP_ECLITE INTEL_ISH_FIRMWARE_DOWNLOADER INTEL_ISH_HID INTEL_SOC_PMIC_CHTWC INTERVAL_TREE_SPAN_ITER IOMMUFD IOMMUFD_DRIVER IOMMUFD_DRIVER_CORE IOMMUFD_TEST IP6_NF_MATCH_AH IP6_NF_MATCH_EUI64 IP6_NF_MATCH_FRAG IP6_NF_MATCH_HL IP6_NF_MATCH_MH IP6_NF_MATCH_OPTS IP6_NF_MATCH_RPFILTER IP6_NF_MATCH_RT IP6_NF_MATCH_SRH IP6_NF_TARGET_NPT IP6_NF_TARGET_SYNPROXY IPV6_FOU IPV6_FOU_TUNNEL IPV6_GRE IPV6_ILA IPV6_MIP6 IPV6_MROUTE IPV6_MROUTE_MULTIPLE_TABLES IPV6_MULTIPLE_TABLES IPV6_OPTIMISTIC_DAD IPV6_PIMSM_V2 IPV6_ROUTER_PREF IPV6_ROUTE_INFO IPV6_RPL_LWTUNNEL IPV6_SEG6_BPF IPV6_SEG6_HMAC IPV6_SEG6_LWTUNNEL IPV6_SIT_6RD IPV6_SUBTREES IPV6_TUNNEL IPV6_VTI IPVLAN IPVLAN_L3S IPVTAP IP_FIB_TRIE_STATS IP_MROUTE_MULTIPLE_TABLES IP_NF_ARP_MANGLE IP_NF_MATCH_AH IP_NF_MATCH_ECN IP_NF_MATCH_RPFILTER IP_NF_MATCH_TTL IP_NF_TARGET_ECN IP_NF_TARGET_SYNPROXY IP_SCTP IRQ_TIME_ACCOUNTING LAPB LCD_CLASS_DEVICE LEDS_CLASS_MULTICOLOR MAC802154 MEDIA_DIGITAL_TV_SUPPORT MEDIA_RADIO_SUPPORT MEDIA_SDR_SUPPORT MEDIA_SUPPORT MEDIA_TEST_SUPPORT MEDIA_USB_SUPPORT MEMORY_HOTPLUG MEMORY_HOTREMOVE MFD_DLN2 MFD_VIPERBOARD MODVERSIONS MPTCP MTD NETFILTER_ADVANCED NET_ACT_GACT NET_ACT_MIRRED NET_IPGRE_DEMUX NFT_COMPAT NFT_COMPAT_ARP NFT_FWD_NETDEV NF_TABLES NF_TABLES_ARP NF_TABLES_NETDEV RADIO_ADAPTERS RADIO_SI4713 RAS RC_CORE REGULATOR RFKILL SND SOUND STAGING TRANSPARENT_HUGEPAGE TRUSTED_KEYS TYPEC TYPEC_MUX_PI3USB30532 USB_LJCA USB_ROLES_INTEL_XHCI USB_ROLE_SWITCH VIDEO_DEV VIRTIO_FS WAN ZONE_DEVICE] disabling configs for [atomic_sleep hang memleak ubsan bug_or_warning kasan locking], they are not needed picked [v6.16 v6.15 v6.14 v6.12 v6.10 v6.8 v6.6 v6.4 v6.1 v5.18 v5.15 v5.12 v5.9 v5.6 v5.3 v5.0 v4.19] out of 39 release tags testing release v6.16 testing commit 038d61fd642278bab63ee8ef722c50d10ab01e8f gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: a52a9cc75c85702298f0342cb54f70456e30a2668f3496f490faabfbce80f9d0 all runs: OK false negative chance: 0.000 # git bisect start b5a4da2c459f79a2c87c867398f1c0c315779781 038d61fd642278bab63ee8ef722c50d10ab01e8f Bisecting: 13178 revisions left to test after this (roughly 14 steps) [18ee2b9b7bd4e2346e467101c973d62300c8ba85] Merge tag 'drm-fixes-2025-08-29' of https://gitlab.freedesktop.org/drm/kernel testing commit 18ee2b9b7bd4e2346e467101c973d62300c8ba85 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 9628d5d394086360addb440253bbb3a86c14314c1c08ef79014befdca38c588f all runs: OK false negative chance: 0.000 # git bisect good 18ee2b9b7bd4e2346e467101c973d62300c8ba85 Bisecting: 5993 revisions left to test after this (roughly 13 steps) [0472b4c78c217f5ee557b636857bce6a4417fb66] Merge branch 'main' of https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git testing commit 0472b4c78c217f5ee557b636857bce6a4417fb66 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: b0eaef1bf99a261f9a5e74ab1401727fd69e50200d5f91a9eb09a73e7324e67f all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls representative crash: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls, types: [NULL-POINTER-DEREFERENCE] # git bisect bad 0472b4c78c217f5ee557b636857bce6a4417fb66 Bisecting: 3589 revisions left to test after this (roughly 12 steps) [026728b353c18a72918421821801317153c34126] Merge branch 'mips-next' of https://git.kernel.org/pub/scm/linux/kernel/git/mips/linux.git testing commit 026728b353c18a72918421821801317153c34126 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: a27e400a59e446fcd5a3a92829548bd58f56f2f4ecc475d0cfc5738637000937 all runs: OK false negative chance: 0.000 # git bisect good 026728b353c18a72918421821801317153c34126 Bisecting: 1957 revisions left to test after this (roughly 11 steps) [8542722a9563ae06a3fdf00896e1218146cc59d2] Merge branch 'docs-next' of git://git.lwn.net/linux.git testing commit 8542722a9563ae06a3fdf00896e1218146cc59d2 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 068a947f02139ef637f5e93fc41f2fbd497135240910cfc0e17fb61d7d7229b7 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls representative crash: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls, types: [NULL-POINTER-DEREFERENCE] # git bisect bad 8542722a9563ae06a3fdf00896e1218146cc59d2 Bisecting: 864 revisions left to test after this (roughly 10 steps) [c54644c3221b6230a9fc0f9f09630b4ef7a6bd79] Merge branch 'for-next' of https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git testing commit c54644c3221b6230a9fc0f9f09630b4ef7a6bd79 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 96d2e57571ad967a3ed25bf2114ab133e3ebfb29bc9c722aae5149ed395c2f76 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls representative crash: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls, types: [NULL-POINTER-DEREFERENCE] # git bisect bad c54644c3221b6230a9fc0f9f09630b4ef7a6bd79 Bisecting: 385 revisions left to test after this (roughly 9 steps) [1af000e9682f97c4a14b0cc8f2f443128d1930c8] Merge branch 'overlayfs-next' of https://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs.git testing commit 1af000e9682f97c4a14b0cc8f2f443128d1930c8 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: d7a5921d64005397b9a5128dbeaac43c15b81c96843c6390320ff009c2881a8b all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls representative crash: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls, types: [NULL-POINTER-DEREFERENCE] # git bisect bad 1af000e9682f97c4a14b0cc8f2f443128d1930c8 Bisecting: 202 revisions left to test after this (roughly 8 steps) [db6dc62c4133b131996935ffbaff0c707515d78b] Merge branch 'for_next' of https://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs.git testing commit db6dc62c4133b131996935ffbaff0c707515d78b gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 1c4674dccba81707ed76156a3fcb2d8cf2e4cf796eb6fecb46a9dd23266d0f78 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls representative crash: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls, types: [NULL-POINTER-DEREFERENCE] # git bisect bad db6dc62c4133b131996935ffbaff0c707515d78b Bisecting: 88 revisions left to test after this (roughly 7 steps) [8f0534ec96e3cbba2ecefe560a482382198c044f] btrfs: mark extent buffer alignment checks as unlikely testing commit 8f0534ec96e3cbba2ecefe560a482382198c044f gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: d45ef10d7284a21b3e92ac8157fadd294ca04091e46dc1cdaaff673ecf8b4b9b all runs: OK false negative chance: 0.000 # git bisect good 8f0534ec96e3cbba2ecefe560a482382198c044f Bisecting: 44 revisions left to test after this (roughly 6 steps) [328560c8ab2406010344c2a56b1ace740ce7945d] Merge branch 'master' of https://github.com/ceph/ceph-client.git testing commit 328560c8ab2406010344c2a56b1ace740ce7945d gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 7d83d1e32bd164ab6b063589ba7fe91258e303622465b72a8c71cbdf0c774911 all runs: OK false negative chance: 0.000 # git bisect good 328560c8ab2406010344c2a56b1ace740ce7945d Bisecting: 19 revisions left to test after this (roughly 5 steps) [1f8f87f17e82b8bd69bd0aaa473bef1cc1b6ecc8] Merge branch 'next' of https://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm.git testing commit 1f8f87f17e82b8bd69bd0aaa473bef1cc1b6ecc8 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 730bda93013e396d737b1e3bfe9413b3e6ed8e0045529783e8b00d5d71e8ce6a all runs: OK false negative chance: 0.000 # git bisect good 1f8f87f17e82b8bd69bd0aaa473bef1cc1b6ecc8 Bisecting: 9 revisions left to test after this (roughly 3 steps) [5241fa31353a8c000540dab3991e7e4b2872f820] Merge branch 'dev' of https://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat.git testing commit 5241fa31353a8c000540dab3991e7e4b2872f820 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: b8e29b234999206f494d72e40ee6242b723d03f87db44208b307d4b018f831db all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls representative crash: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls, types: [NULL-POINTER-DEREFERENCE] # git bisect bad 5241fa31353a8c000540dab3991e7e4b2872f820 Bisecting: 4 revisions left to test after this (roughly 2 steps) [a7d23a1767308a944a1b02f8f312b69921a11bb4] exfat: optimize allocation bitmap loading time testing commit a7d23a1767308a944a1b02f8f312b69921a11bb4 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 7d219e26c61f8b5e7d6a33b7f1d4447fe08ad6318bd32209c24967d4b2095ac2 all runs: OK false negative chance: 0.000 # git bisect good a7d23a1767308a944a1b02f8f312b69921a11bb4 Bisecting: 2 revisions left to test after this (roughly 1 step) [a87a82f87c8101fe5124ec7fa19c5e9ab44a1b0a] exfat: Add support for FS_IOC_{GET,SET}FSLABEL testing commit a87a82f87c8101fe5124ec7fa19c5e9ab44a1b0a gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: f4f8f7c5d92eb7dc6dd3d7b9baa728585d4b477954db294f2b0c2ed6f7986ba9 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls representative crash: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls, types: [NULL-POINTER-DEREFERENCE] # git bisect bad a87a82f87c8101fe5124ec7fa19c5e9ab44a1b0a Bisecting: 0 revisions left to test after this (roughly 0 steps) [acab02ffcd6b1e796570ffa9658c90c8f09caae3] exfat: support modifying mount options via remount testing commit acab02ffcd6b1e796570ffa9658c90c8f09caae3 gcc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 kernel signature: 8fb6ee2da6555a53c8ed88d60e58481bedf8109350b7abe284f3a228d6b14ec1 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls representative crash: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls, types: [NULL-POINTER-DEREFERENCE] # git bisect bad acab02ffcd6b1e796570ffa9658c90c8f09caae3 acab02ffcd6b1e796570ffa9658c90c8f09caae3 is the first bad commit commit acab02ffcd6b1e796570ffa9658c90c8f09caae3 Author: Yuezhang Mo Date: Thu Sep 11 16:54:31 2025 +0800 exfat: support modifying mount options via remount Before this commit, all exfat-defined mount options could not be modified dynamically via remount, and no error was returned. After this commit, these three exfat-defined mount options (discard, zero_size_dir, and errors) can be modified dynamically via remount. While other exfat-defined mount options cannot be modified dynamically via remount because their old settings are cached in inodes or dentries, modifying them will be rejected with an error. Signed-off-by: Yuezhang Mo Signed-off-by: Namjae Jeon fs/exfat/super.c | 44 ++++++++++++++++++++++++++++++++++++++------ 1 file changed, 38 insertions(+), 6 deletions(-) accumulated error probability: 0.00 culprit signature: 8fb6ee2da6555a53c8ed88d60e58481bedf8109350b7abe284f3a228d6b14ec1 parent signature: 7d219e26c61f8b5e7d6a33b7f1d4447fe08ad6318bd32209c24967d4b2095ac2 revisions tested: 22, total time: 11h49m56.21611245s (build: 8h27m6.746414681s, test: 2h39m31.305854012s) first bad commit: acab02ffcd6b1e796570ffa9658c90c8f09caae3 exfat: support modifying mount options via remount recipients (to): ["linkinjeon@kernel.org" "linkinjeon@kernel.org" "linux-fsdevel@vger.kernel.org" "sj1557.seo@samsung.com" "yuezhang.mo@sony.com"] recipients (cc): ["linux-kernel@vger.kernel.org" "yuezhang.mo@sony.com"] crash: BUG: unable to handle kernel NULL pointer dereference in exfat_utf16_to_nls BUG: kernel NULL pointer dereference, address: 0000000000000010 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 800000016b558067 P4D 800000016b558067 PUD 0 Oops: Oops: 0000 [#1] SMP PTI CPU: 1 UID: 0 PID: 3187 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(none) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:exfat_convert_ucs2_to_char fs/exfat/nls.c:441 [inline] RIP: 0010:__exfat_utf16_to_nls fs/exfat/nls.c:554 [inline] RIP: 0010:exfat_utf16_to_nls+0xcf/0x230 fs/exfat/nls.c:638 Code: 00 00 31 f6 81 fa 00 dc 00 00 40 0f 94 c6 4c 0f 44 e1 41 01 f5 eb 35 c6 44 24 08 00 66 83 ff 7f 77 04 89 f8 eb 26 48 8b 04 24 <4c> 8b 58 10 48 8d 74 24 08 ba 06 00 00 00 2e e8 d5 93 8a 1e 85 c0 RSP: 0018:ffffc90001db7b00 EFLAGS: 00010212 RAX: 0000000000000000 RBX: ffff888103a89004 RCX: 0000000000000001 RDX: 0000000000000004 RSI: ffffc90001db7bc0 RDI: 00000000000000e1 RBP: 00000000000005ff R08: 0000000000000000 R09: ffff88817c1ba000 R10: 0000000000000100 R11: 0000000000000000 R12: ffffc90001db7bc8 R13: 0000000000000004 R14: 0000000000000004 R15: 0000000000000600 FS: 0000555573a19500(0000) GS:ffff8882b37b9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000102740000 CR4: 00000000003506f0 Call Trace: exfat_readdir fs/exfat/dir.c:143 [inline] exfat_iterate+0x69c/0x8f0 fs/exfat/dir.c:243 wrap_directory_iterator+0x4a/0x70 fs/readdir.c:65 iterate_dir+0xd8/0x140 fs/readdir.c:108 __do_sys_getdents64 fs/readdir.c:410 [inline] __se_sys_getdents64+0x69/0x100 fs/readdir.c:396 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x8f/0x250 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5fa0dc1833 Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 32 3d f8 ff 66 90 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 a8 ff ff ff f7 d8 RSP: 002b:00007ffc9ba81438 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 0000555573a344e0 RCX: 00007f5fa0dc1833 RDX: 0000000000008000 RSI: 0000555573a344e0 RDI: 0000000000000005 RBP: 0000555573a344b4 R08: 0000000000028b61 R09: 0000000000000000 R10: 00007f5fa0fb7cc0 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 0000555573a344b0 R15: 00007ffc9ba836f0 Modules linked in: CR2: 0000000000000010 ---[ end trace 0000000000000000 ]--- RIP: 0010:exfat_convert_ucs2_to_char fs/exfat/nls.c:441 [inline] RIP: 0010:__exfat_utf16_to_nls fs/exfat/nls.c:554 [inline] RIP: 0010:exfat_utf16_to_nls+0xcf/0x230 fs/exfat/nls.c:638 Code: 00 00 31 f6 81 fa 00 dc 00 00 40 0f 94 c6 4c 0f 44 e1 41 01 f5 eb 35 c6 44 24 08 00 66 83 ff 7f 77 04 89 f8 eb 26 48 8b 04 24 <4c> 8b 58 10 48 8d 74 24 08 ba 06 00 00 00 2e e8 d5 93 8a 1e 85 c0 RSP: 0018:ffffc90001db7b00 EFLAGS: 00010212 RAX: 0000000000000000 RBX: ffff888103a89004 RCX: 0000000000000001 RDX: 0000000000000004 RSI: ffffc90001db7bc0 RDI: 00000000000000e1 RBP: 00000000000005ff R08: 0000000000000000 R09: ffff88817c1ba000 R10: 0000000000000100 R11: 0000000000000000 R12: ffffc90001db7bc8 R13: 0000000000000004 R14: 0000000000000004 R15: 0000000000000600 FS: 0000555573a19500(0000) GS:ffff8882b37b9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000102740000 CR4: 00000000003506f0 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 31 f6 xor %esi,%esi 4: 81 fa 00 dc 00 00 cmp $0xdc00,%edx a: 40 0f 94 c6 sete %sil e: 4c 0f 44 e1 cmove %rcx,%r12 12: 41 01 f5 add %esi,%r13d 15: eb 35 jmp 0x4c 17: c6 44 24 08 00 movb $0x0,0x8(%rsp) 1c: 66 83 ff 7f cmp $0x7f,%di 20: 77 04 ja 0x26 22: 89 f8 mov %edi,%eax 24: eb 26 jmp 0x4c 26: 48 8b 04 24 mov (%rsp),%rax * 2a: 4c 8b 58 10 mov 0x10(%rax),%r11 <-- trapping instruction 2e: 48 8d 74 24 08 lea 0x8(%rsp),%rsi 33: ba 06 00 00 00 mov $0x6,%edx 38: 2e e8 d5 93 8a 1e cs call 0x1e8a9413 3e: 85 c0 test %eax,%eax