ci2 starts bisection 2025-11-17 11:57:51.783440422 +0000 UTC m=+154.586456498
bisecting fixing commit since 083fc6d7fa0d974a3663b97c8b0466737a544236
building syzkaller on 001c90610fb2f2ac7cbbc9cd6af3f547b821a8ad
ensuring issue is reproducible on original commit 083fc6d7fa0d974a3663b97c8b0466737a544236

testing commit 083fc6d7fa0d974a3663b97c8b0466737a544236 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 4fb55decea26e6a11e8feccdd7be485fea630d286d59767334e4aa79b6bc0da1
run #0: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #1: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #2: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #3: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #4: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #5: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #6: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #7: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #8: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #9: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #10: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #11: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
representative crash: KASAN: use-after-free Read in __ext4_check_dir_entry, types: [KASAN-USE-AFTER-FREE-READ]
check whether we can drop unnecessary instrumentation
disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed
testing commit 083fc6d7fa0d974a3663b97c8b0466737a544236 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: f8d8045084373c324406bf8e1cf40f70209f9313a66871709b9941a3704d76c1
run #0: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #1: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #2: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #3: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #4: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
representative crash: KASAN: slab-use-after-free Read in __ext4_check_dir_entry, types: [KASAN-USE-AFTER-FREE-READ]
the bug reproduces without the instrumentation
disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed
kconfig minimization: base=4109 full=8349 leaves diff=2174
split chunks (needed=false): <2174>
split chunk #0 of len 2174 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 083fc6d7fa0d974a3663b97c8b0466737a544236 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 6e7dff63361409eb76783429e6aba2e69cac42612bff7e9e1618bcf968fc83af
run #0: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #1: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #2: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
representative crash: KASAN: slab-use-after-free Read in __ext4_check_dir_entry, types: [KASAN-USE-AFTER-FREE-READ]
testing without sub-chunk 2/5
disabling configs for [locking atomic_sleep hang memleak ubsan bug_or_warning], they are not needed
testing commit 083fc6d7fa0d974a3663b97c8b0466737a544236 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 1d378192df38b5a68396c703b139783b924e60225b1bd0355d6bf0c1f004c03d
run #0: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #1: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #2: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #3: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #4: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #5: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #6: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #7: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #8: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #9: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #10: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
representative crash: KASAN: slab-use-after-free Read in __ext4_check_dir_entry, types: [KASAN-USE-AFTER-FREE-READ]
the chunk can be dropped
testing without sub-chunk 3/5
disabling configs for [memleak ubsan bug_or_warning locking atomic_sleep hang], they are not needed
testing commit 083fc6d7fa0d974a3663b97c8b0466737a544236 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 81946488c66cf88a21b5c17c6947cbe1b15b868db155483ab6ef1acf3aa3f2c2
run #0: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #1: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #2: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #3: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #4: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #5: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #6: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #7: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
representative crash: KASAN: slab-use-after-free Read in __ext4_check_dir_entry, types: [KASAN-USE-AFTER-FREE-READ]
the chunk can be dropped
testing without sub-chunk 4/5
disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed
testing commit 083fc6d7fa0d974a3663b97c8b0466737a544236 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 14ecc0fec0a9bad2fc11b4270e14bc53d9c28f0433ef67463e3b7a91bf47c9d9
run #0: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #1: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #2: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #3: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #4: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #5: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #6: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #7: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #8: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #9: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #10: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #11: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
representative crash: KASAN: use-after-free Read in __ext4_check_dir_entry, types: [KASAN-USE-AFTER-FREE-READ]
the chunk can be dropped
testing without sub-chunk 5/5
disabling configs for [bug_or_warning locking atomic_sleep hang memleak ubsan], they are not needed
testing commit 083fc6d7fa0d974a3663b97c8b0466737a544236 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: f33cfb2004defec199ed30e688bbc9423acd38a5da48f2264981c66f745103e3
run #0: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #1: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #2: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #3: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #4: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #5: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #6: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #7: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #8: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
representative crash: KASAN: slab-use-after-free Read in __ext4_check_dir_entry, types: [KASAN-USE-AFTER-FREE-READ]
the chunk can be dropped
minimized to 435 configs; suspects: [6LOWPAN 6LOWPAN_GHC_EXT_HDR_DEST 6LOWPAN_GHC_EXT_HDR_FRAG 6LOWPAN_GHC_EXT_HDR_HOP 6LOWPAN_GHC_EXT_HDR_ROUTE 6LOWPAN_GHC_ICMPV6 6LOWPAN_GHC_UDP 6LOWPAN_NHC 6LOWPAN_NHC_DEST 6LOWPAN_NHC_FRAGMENT 6LOWPAN_NHC_HOP 6LOWPAN_NHC_IPV6 6LOWPAN_NHC_MOBILITY 6LOWPAN_NHC_ROUTING 6LOWPAN_NHC_UDP 6PACK 842_COMPRESS 842_DECOMPRESS 9P_FSCACHE 9P_FS_POSIX_ACL 9P_FS_SECURITY ACORN_PARTITION ACORN_PARTITION_ADFS ACORN_PARTITION_CUMANA ACORN_PARTITION_EESOX ACORN_PARTITION_ICS ACORN_PARTITION_POWERTEC ACORN_PARTITION_RISCIX ACPI_NFIT ACPI_NHLT ACPI_PLATFORM_PROFILE ADFS_FS AFFS_FS AFS_FS AFS_FSCACHE AF_KCM AF_RXRPC AF_RXRPC_IPV6 AIX_PARTITION AMD_SFH_HID AMIGA_PARTITION ANDROID_BINDERFS ANDROID_BINDER_IPC ANON_VMA_NAME APERTURE_HELPERS APPLE_MFI_FASTCHARGE AR5523 ARCH_HAS_USER_SHADOW_STACK ARCH_SUPPORTS_CFI_CLANG ASM_MODVERSIONS ASUS_TF103C_DOCK ASYNC_CORE ASYNC_MEMCPY ASYNC_PQ ASYNC_RAID6_RECOV ASYNC_TX_DMA ASYNC_XOR AS_AVX512 AS_GFNI AS_VAES AS_VPCLMULQDQ ATARI_PARTITION ATA_GENERIC ATA_OVER_ETH ATH10K ATH10K_CE ATH10K_LEDS ATH10K_PCI ATH10K_USB ATH11K ATH6KL ATH6KL_USB ATH9K ATH9K_AHB ATH9K_BTCOEX_SUPPORT ATH9K_CHANNEL_CONTEXT ATH9K_COMMON ATH9K_COMMON_DEBUG ATH9K_COMMON_SPECTRAL ATH9K_DEBUGFS ATH9K_DYNACK ATH9K_HTC ATH9K_HTC_DEBUGFS ATH9K_HW ATH9K_PCI ATH9K_PCOEM ATH9K_RFKILL ATH_COMMON ATM ATM_BR2684 ATM_CLIP ATM_DRIVERS ATM_LANE ATM_MPOA ATM_TCP AUXILIARY_BUS AX25 AX25_DAMA_SLAVE AX88796B_PHY BAREUDP BATMAN_ADV BATMAN_ADV_BATMAN_V BATMAN_ADV_BLA BATMAN_ADV_DAT BATMAN_ADV_MCAST BATMAN_ADV_NC BCACHE BCACHEFS_DEBUG BCACHEFS_ERASURE_CODING BCACHEFS_FS BCACHEFS_POSIX_ACL BCACHEFS_QUOTA BCACHEFS_SIX_OPTIMISTIC_SPIN BCMA BCMA_HOST_PCI_POSSIBLE BEFS_FS BFQ_CGROUP_DEBUG BFQ_GROUP_IOSCHED BFS_FS BIG_KEYS BLK_CGROUP_PUNT_BIO BLK_CGROUP_RWSTAT BLK_DEV_BSGLIB BLK_DEV_INTEGRITY BLK_DEV_NBD BLK_DEV_NULL_BLK BLK_DEV_NULL_BLK_FAULT_INJECTION BLK_DEV_NVME BLK_DEV_PMEM BLK_DEV_RAM BLK_DEV_RNBD BLK_DEV_RNBD_CLIENT BLK_DEV_THROTTLING BLK_ICQ BLK_INLINE_ENCRYPTION BLK_INLINE_ENCRYPTION_FALLBACK BLK_WBT BLK_WBT_MQ BONDING BOOT_VESA_SUPPORT BPF_EVENTS BPF_JIT BPF_JIT_ALWAYS_ON BPF_JIT_DEFAULT_ON BPF_LSM BPF_PRELOAD BPF_PRELOAD_UMD BPF_SYSCALL BPQETHER BRIDGE BRIDGE_CFM BRIDGE_EBT_802_3 BRIDGE_EBT_AMONG BRIDGE_EBT_ARP BRIDGE_EBT_ARPREPLY BRIDGE_EBT_DNAT BRIDGE_EBT_IP BRIDGE_EBT_IP6 BRIDGE_EBT_LIMIT BRIDGE_EBT_LOG BRIDGE_EBT_MARK BRIDGE_EBT_MARK_T BRIDGE_EBT_NFLOG BRIDGE_EBT_PKTTYPE BRIDGE_EBT_REDIRECT BRIDGE_EBT_SNAT BRIDGE_EBT_STP BRIDGE_EBT_VLAN BRIDGE_IGMP_SNOOPING BRIDGE_MRP BRIDGE_NF_EBTABLES BRIDGE_VLAN_FILTERING BSD_DISKLABEL BSD_PROCESS_ACCT_V3 BT BTRFS_ASSERT BTRFS_FS BTRFS_FS_POSIX_ACL BTRFS_FS_REF_VERIFY BTT BT_6LOWPAN BT_ATH3K BT_BCM BT_BNEP BT_BNEP_MC_FILTER BT_BNEP_PROTO_FILTER BT_BREDR BT_HCIBCM203X BT_HCIBFUSB BT_HCIBPA10X BT_HCIBTUSB BT_HCIBTUSB_AUTOSUSPEND BT_HCIBTUSB_BCM BT_HCIBTUSB_MTK BT_HCIBTUSB_POLL_SYNC BT_HCIBTUSB_RTL BT_HCIUART BT_HCIUART_3WIRE BT_HCIUART_AG6XX BT_HCIUART_BCSP BT_HCIUART_H4 BT_HCIUART_LL BT_HCIUART_MRVL BT_HCIUART_QCA BT_HCIUART_SERDEV BT_HCIVHCI BT_INTEL BT_LE BT_LEDS BT_LE_L2CAP_ECRED BT_MRVL BT_MRVL_SDIO BT_MSFTEXT BT_MTK BT_MTKSDIO BT_MTKUART BT_QCA BT_RFCOMM BT_RFCOMM_TTY BT_RTL CACHEFILES CAIF CAIF_DEBUG CAIF_DRIVERS CAIF_NETDEV CAIF_TTY CAIF_USB CAIF_VIRTIO CAN CAN_8DEV_USB CAN_BCM CAN_CALC_BITTIMING CAN_DEV CAN_EMS_USB CAN_ESD_USB CAN_ETAS_ES58X CAN_F81604 CAN_GS_USB CAN_GW CAN_IFI_CANFD CAN_ISOTP CAN_J1939 CAN_KVASER_USB CAN_MCBA_USB CAN_NETLINK CAN_PEAK_USB CAN_RAW CAN_RX_OFFLOAD CAN_SLCAN CAN_UCAN CAN_VCAN CAN_VXCAN CARL9170 CARL9170_HWRNG CARL9170_LEDS CARL9170_WPC CEC_CORE CEPH_FS CEPH_FSCACHE CEPH_FS_POSIX_ACL CEPH_LIB CEPH_LIB_USE_DNS_RESOLVER CFG80211 CFG80211_CRDA_SUPPORT CFG80211_DEBUGFS CFG80211_DEFAULT_PS CFG80211_REQUIRE_SIGNED_REGDB CFG80211_USE_KERNEL_REGDB_KEYS CFG80211_WEXT CFS_BANDWIDTH CHARGER_ISP1704 CHR_DEV_ST CIFS CIFS_ALLOW_INSECURE_LEGACY CIFS_DEBUG CIFS_DFS_UPCALL CIFS_FSCACHE CIFS_POSIX CIFS_SMB_DIRECT CIFS_SWN_UPCALL CIFS_UPCALL CIFS_XATTR CLOSURES CLS_U32_MARK CLS_U32_PERF CMA CMA_SIZE_SEL_MAX CMDLINE_PARTITION COMEDI COMEDI_8254 COMEDI_8255 COMEDI_8255_PCI COMEDI_8255_SA COMEDI_ADL_PCI9118 COMEDI_ADQ12B COMEDI_AIO_AIO12_8 COMEDI_AIO_IIRO_16 COMEDI_AMPLC_DIO200 COMEDI_AMPLC_DIO200_ISA COMEDI_AMPLC_PC236 COMEDI_AMPLC_PC236_ISA COMEDI_AMPLC_PC263_ISA COMEDI_BOND COMEDI_C6XDIGIO COMEDI_DAC02 COMEDI_DAS08 COMEDI_DAS08_ISA COMEDI_DAS16M1 COMEDI_DAS1800 COMEDI_DAS6402 COMEDI_DAS800 COMEDI_DMM32AT COMEDI_DT2801 COMEDI_DT2811 COMEDI_DT2814 COMEDI_DT2815 COMEDI_DT2817 COMEDI_DT282X COMEDI_DT9812 COMEDI_FL512 COMEDI_ISADMA COMEDI_ISA_DRIVERS COMEDI_KCOMEDILIB COMEDI_MISC_DRIVERS COMEDI_MPC624 COMEDI_MULTIQ3 COMEDI_NI_ATMIO16D COMEDI_NI_AT_A2150 COMEDI_NI_AT_AO COMEDI_NI_DAQ_700_CS COMEDI_NI_LABPC COMEDI_NI_LABPC_CS COMEDI_NI_LABPC_ISA COMEDI_NI_LABPC_ISADMA COMEDI_NI_LABPC_PCI COMEDI_NI_USB6501 COMEDI_PARPORT COMEDI_PCI_DRIVERS COMEDI_PCL711 COMEDI_PCL724 COMEDI_PCL726 COMEDI_PCL730 COMEDI_PCL812 COMEDI_PCL816 COMEDI_PCL818 COMEDI_PCM3724 COMEDI_PCMAD COMEDI_PCMCIA_DRIVERS COMEDI_PCMDA12 COMEDI_PCMMIO COMEDI_PCMUIO COMEDI_RTI800 COMEDI_RTI802 COMEDI_S526 COMEDI_TEST COMEDI_USBDUX COMEDI_USBDUXFAST COMEDI_USBDUXSIGMA COMEDI_USB_DRIVERS COMEDI_VMK80XX COMPAT_NETLINK_MESSAGES COUNTER CRAMFS CRAMFS_BLOCKDEV CRAMFS_MTD CRC64 CRC64_ARCH CRC8 CRC_ITU_T CRC_T10DIF CRC_T10DIF_ARCH CRYPTO_842 CRYPTO_ADIANTUM CRYPTO_AEGIS128 CRYPTO_AEGIS128_AESNI_SSE2 CRYPTO_AES_NI_INTEL CRYPTO_AES_TI CRYPTO_ANSI_CPRNG CRYPTO_ANUBIS CRYPTO_ARC4 CRYPTO_ARCH_HAVE_LIB_BLAKE2S CRYPTO_ARCH_HAVE_LIB_CHACHA CRYPTO_ARCH_HAVE_LIB_CURVE25519 CRYPTO_ARCH_HAVE_LIB_POLY1305 CRYPTO_ARIA CRYPTO_ARIA_AESNI_AVX_X86_64 CRYPTO_BLAKE2B CRYPTO_BLAKE2S_X86 CRYPTO_BLOWFISH CRYPTO_BLOWFISH_COMMON CRYPTO_BLOWFISH_X86_64 CRYPTO_CAMELLIA CRYPTO_CAMELLIA_AESNI_AVX2_X86_64 CRYPTO_CAMELLIA_AESNI_AVX_X86_64 CRYPTO_CAMELLIA_X86_64 CRYPTO_CAST5 CRYPTO_CAST5_AVX_X86_64 CRYPTO_CAST6 CRYPTO_CAST6_AVX_X86_64 CRYPTO_CAST_COMMON CRYPTO_CHACHA20 CRYPTO_CHACHA20POLY1305 CRYPTO_CHACHA20_X86_64 CRYPTO_CRC32C CRYPTO_CRYPTD CRYPTO_CTS CRYPTO_CURVE25519 CRYPTO_CURVE25519_X86 CRYPTO_DEFLATE CRYPTO_DES CRYPTO_DES3_EDE_X86_64 CRYPTO_DEV_CCP CRYPTO_DEV_CCP_DD CRYPTO_DEV_PADLOCK CRYPTO_DEV_PADLOCK_AES CRYPTO_DEV_PADLOCK_SHA CRYPTO_DEV_QAT CRYPTO_DEV_QAT_C3XXX CRYPTO_DEV_QAT_C3XXXVF CRYPTO_DEV_QAT_C62X CRYPTO_DEV_QAT_C62XVF CRYPTO_DEV_QAT_DH895xCC CRYPTO_DEV_QAT_DH895xCCVF CRYPTO_DEV_VIRTIO CRYPTO_DH CRYPTO_DRBG_CTR CRYPTO_DRBG_HASH CRYPTO_ECDH CRYPTO_ECRDSA CRYPTO_ENGINE CRYPTO_ESSIV CRYPTO_FCRYPT CRYPTO_GHASH_CLMUL_NI_INTEL CRYPTO_HCTR2 CRYPTO_HKDF CRYPTO_KDF800108_CTR CRYPTO_KHAZAD CRYPTO_KPP CRYPTO_KRB5 CRYPTO_KRB5ENC CRYPTO_LIB_ARC4 CRYPTO_LIB_BLAKE2S_GENERIC CRYPTO_LIB_CHACHA CRYPTO_LIB_CHACHA20POLY1305 CRYPTO_LIB_CHACHA_GENERIC CRYPTO_LIB_CURVE25519 CRYPTO_LIB_CURVE25519_GENERIC CRYPTO_LIB_CURVE25519_INTERNAL CRYPTO_LIB_DES CRYPTO_LIB_POLY1305 CRYPTO_LIB_POLY1305_GENERIC CRYPTO_LIB_SM3 CRYPTO_LRW CRYPTO_LZ4 CRYPTO_LZ4HC CRYPTO_MICHAEL_MIC CRYPTO_NHPOLY1305 CRYPTO_NHPOLY1305_AVX2 CRYPTO_NHPOLY1305_SSE2 CRYPTO_PCBC CRYPTO_PCRYPT CRYPTO_POLY1305_X86_64 CRYPTO_POLYVAL CRYPTO_POLYVAL_CLMUL_NI CRYPTO_RMD160 CRYPTO_SEED CRYPTO_SERPENT CRYPTO_SERPENT_AVX2_X86_64 CRYPTO_SERPENT_AVX_X86_64 CRYPTO_SERPENT_SSE2_X86_64 CRYPTO_SM3_AVX_X86_64 CRYPTO_SM4 CRYPTO_SM4_AESNI_AVX2_X86_64 CRYPTO_SM4_AESNI_AVX_X86_64 CRYPTO_SM4_GENERIC CRYPTO_STREEBOG CRYPTO_TEA CRYPTO_TWOFISH CRYPTO_TWOFISH_AVX_X86_64 CRYPTO_TWOFISH_COMMON CRYPTO_TWOFISH_X86_64 CRYPTO_TWOFISH_X86_64_3WAY CRYPTO_USER CRYPTO_USER_API CRYPTO_USER_API_AEAD CRYPTO_USER_API_ENABLE_OBSOLETE CRYPTO_USER_API_HASH CRYPTO_USER_API_RNG CRYPTO_USER_API_SKCIPHER CRYPTO_WP512 CRYPTO_XCBC CRYPTO_XCTR CRYPTO_XTS CRYPTO_XXHASH CRYPTO_ZSTD CUSE CYPRESS_FIRMWARE DAMON DAMON_PADDR DAMON_RECLAIM DAMON_VADDR DCA DCB DEBUG_VFS DEFAULT_CODEL DEVICE_MIGRATION DMA_CMA FSCACHE FUSE_FS GPIOLIB HAMRADIO INFINIBAND INFINIBAND_ADDR_TRANS INFINIBAND_RTRS_CLIENT IOSCHED_BFQ ISA_BUS LIBNVDIMM MAC80211 MAC80211_DEBUGFS MAC80211_LEDS MEDIA_SUPPORT MMC MTD NET_CLS_U32 NET_SCH_DEFAULT PARTITION_ADVANCED PCCARD PCMCIA RFKILL SERIAL_DEV_BUS TLS TLS_DEVICE USB_GADGET USB_PHY VLAN_8021Q WANT_COMPAT_NETLINK_MESSAGES WEXT_CORE WIRELESS WLAN WLAN_VENDOR_ATH]
disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed
testing current HEAD 6a23ae0a96a600d1d12557add110e0bb6e32730c
testing commit 6a23ae0a96a600d1d12557add110e0bb6e32730c gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 5d5d1567240916bc7005cfcc994593ad397ea92bb1a2aa99b50c36888fe01ad4
run #0: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #1: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #2: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #3: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #4: crashed: KASAN: slab-use-after-free Read in __ext4_check_dir_entry
run #5: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #6: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #7: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
representative crash: KASAN: use-after-free Read in __ext4_check_dir_entry, types: [KASAN-USE-AFTER-FREE-READ]
crash still not fixed/happens on the oldest tested release
reproducer is flaky (0.45 repro chance estimate)
revisions tested: 8, total time: 4h19m47.189626662s (build: 57m9.43943194s, test: 1h37m9.577306886s)
crash still not fixed or there were kernel test errors
commit msg: Linux 6.18-rc6
crash: KASAN: use-after-free Read in __ext4_check_dir_entry
EXT4-fs warning (device loop1): dx_probe:801: inode #2: comm syz.1.197: Unrecognised inode hash code 4
EXT4-fs warning (device loop1): dx_probe:934: inode #2: comm syz.1.197: Corrupt directory, running e2fsck is recommended
==================================================================
BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x4d6/0x730 fs/ext4/dir.c:85
Read of size 2 at addr ffff8881121b8003 by task syz.1.197/5380

CPU: 0 UID: 0 PID: 5380 Comm: syz.1.197 Not tainted syzkaller #0 PREEMPT(none) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 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
 __ext4_check_dir_entry+0x4d6/0x730 fs/ext4/dir.c:85
 ext4_readdir+0xae9/0x2d10 fs/ext4/dir.c:262
 iterate_dir+0x1aa/0x4c0 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:410 [inline]
 __se_sys_getdents64+0xd3/0x1b0 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: 0033:0x7f2ce3b4eec9
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:00007f2ce31be038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007f2ce3da5fa0 RCX: 00007f2ce3b4eec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007f2ce3bd1f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2ce3da6038 R14: 00007f2ce3da5fa0 R15: 00007ffce89b4df8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8881121b8b40 pfn:0x1121b8
flags: 0x200000000000000(node=0|zone=2)
page_type: f0(buddy)
raw: 0200000000000000 ffffea00049c2388 ffffea0004a05208 0000000000000000
raw: ffff8881121b8b40 0000000000000001 00000000f0000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1484, tgid 1484 (sh), ts 37993118520, free_ts 121001515908
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x168/0x1a0 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x393b/0x3b30 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x26b/0x460 mm/page_alloc.c:5183
 alloc_pages_mpol+0xcb/0x270 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:3059 [inline]
 allocate_slab+0x96/0x2f0 mm/slub.c:3232
 new_slab mm/slub.c:3286 [inline]
 ___slab_alloc+0xb4c/0x1360 mm/slub.c:4655
 __kmem_cache_alloc_bulk+0x198/0x3e0 mm/slub.c:7406
 refill_sheaf mm/slub.c:2637 [inline]
 __pcs_replace_empty_main+0x236/0x3b0 mm/slub.c:5048
 alloc_from_pcs mm/slub.c:5146 [inline]
 slab_alloc_node mm/slub.c:5273 [inline]
 kmem_cache_alloc_noprof+0x405/0x620 mm/slub.c:5295
 vm_area_alloc+0x1f/0x130 mm/vma_init.c:32
 __mmap_new_vma mm/vma.c:2461 [inline]
 __mmap_region mm/vma.c:2670 [inline]
 mmap_region+0xd00/0x1ba0 mm/vma.c:2740
 do_mmap+0x930/0xc30 mm/mmap.c:558
 vm_mmap_pgoff+0x1c0/0x370 mm/util.c:581
 ksys_mmap_pgoff+0x2be/0x3f0 mm/mmap.c:604
 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
page last free pid 23 tgid 23 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0xa96/0xc00 mm/page_alloc.c:2906
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0xbe2/0x1570 kernel/rcu/tree.c:2861
 handle_softirqs+0x19d/0x500 kernel/softirq.c:622
 run_ksoftirqd+0x28/0x40 kernel/softirq.c:1063
 smpboot_thread_fn+0x3f7/0x7d0 kernel/smpboot.c:160
 kthread+0x59b/0x690 kernel/kthread.c:463
 ret_from_fork+0x15e/0x2f0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff8881121b7f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881121b7f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8881121b8000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff8881121b8080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881121b8100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================