ci2 starts bisection 2025-08-11 21:55:40.381327204 +0000 UTC m=+12159.380322387 bisecting fixing commit since dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 building syzkaller on 3cda49cfaa8556b73277ccd7e75952f0f2de2d74 ensuring issue is reproducible on original commit dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 testing commit dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: 3a71a222ad1b540ad1d67d52d6f85578dbc2f90fba2a80dbe5d0cb452dcb315b all runs: crashed: general protection fault in htb_qlen_notify representative crash: general protection fault in htb_qlen_notify, types: [DoS] check whether we can drop unnecessary instrumentation disabling configs for [atomic_sleep hang memleak ubsan bug_or_warning kasan locking], they are not needed testing commit dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: 0ca5b2adef4133d23dacb8a68b1f988b822012248fad412c4abb71400aba5514 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify representative crash: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify, types: [NULL-POINTER-DEREFERENCE] the bug reproduces without the instrumentation disabling configs for [hang memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed kconfig minimization: base=3829 full=7620 leaves diff=2130 split chunks (needed=false): <2130> split chunk #0 of len 2130 into 5 parts testing without sub-chunk 1/5 disabling configs for [atomic_sleep hang memleak ubsan bug_or_warning kasan locking], they are not needed testing commit dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: 15072f7856910bd94de0a2df0b07e4c74af06cd6c8113726c81d87ce7db9ee05 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify representative crash: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify, 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 dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: 8727d1e2d329bdaec20e0beafe407f3cf994ec4f14e605ed65a8c2b023e5c086 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify representative crash: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify, types: [NULL-POINTER-DEREFERENCE] the chunk can be dropped testing without sub-chunk 3/5 disabling configs for [locking atomic_sleep hang memleak ubsan bug_or_warning kasan], they are not needed testing commit dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: 59927cfc51ad1bbbca7e93df295ff7accf2c3b4ef82782ac0ae561a41a0ef4d4 all runs: OK false negative chance: 0.000 testing without sub-chunk 4/5 disabling configs for [kasan locking atomic_sleep hang memleak ubsan bug_or_warning], they are not needed testing commit dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: c8329d1a2174934c9fa90b67d9309580b2796de7306c68a3d1f9b325057a9d5a all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify representative crash: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify, types: [NULL-POINTER-DEREFERENCE] the chunk can be dropped testing without sub-chunk 5/5 disabling configs for [bug_or_warning kasan locking atomic_sleep hang memleak ubsan], they are not needed testing commit dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: 3490897b0f5980d72afc283ba6f98156b9f3fb10ddd8236b0f525c6a72cc3f37 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify representative crash: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify, types: [NULL-POINTER-DEREFERENCE] the chunk can be dropped minimized to 426 configs; suspects: [AX25 BRIDGE BRIDGE_NETFILTER CAN CFG80211 CHECKPOINT_RESTORE DVB_CORE FB FSCACHE HAMRADIO HSR INFINIBAND INFINIBAND_ADDR_TRANS INFINIBAND_USER_ACCESS INPUT_JOYSTICK INPUT_MOUSE IP6_NF_RAW IPV6_MULTIPLE_TABLES IP_NF_MATCH_TTL IP_NF_RAW IP_NF_SECURITY IP_NF_TARGET_CLUSTERIP IP_NF_TARGET_ECN IP_NF_TARGET_NETMAP IP_NF_TARGET_REDIRECT IP_NF_TARGET_SYNPROXY IP_NF_TARGET_TTL IP_ROUTE_CLASSID IP_SET IP_SET_BITMAP_IP IP_SET_BITMAP_IPMAC IP_SET_BITMAP_PORT IP_SET_HASH_IP IP_SET_HASH_IPMAC IP_SET_HASH_IPMARK IP_SET_HASH_IPPORT IP_SET_HASH_IPPORTIP IP_SET_HASH_IPPORTNET IP_SET_HASH_MAC IP_SET_HASH_NET IP_SET_HASH_NETIFACE IP_SET_HASH_NETNET IP_SET_HASH_NETPORT IP_SET_HASH_NETPORTNET IP_SET_LIST_SET IP_VS IP_VS_DH IP_VS_FO IP_VS_FTP IP_VS_IPV6 IP_VS_LBLC IP_VS_LBLCR IP_VS_LC IP_VS_MH IP_VS_NFCT IP_VS_NQ IP_VS_OVF IP_VS_PE_SIP IP_VS_PROTO_AH IP_VS_PROTO_AH_ESP IP_VS_PROTO_ESP IP_VS_PROTO_SCTP IP_VS_PROTO_TCP IP_VS_PROTO_UDP IP_VS_RR IP_VS_SED IP_VS_SH IP_VS_TWOS IP_VS_WLC IP_VS_WRR IRQ_BYPASS_MANAGER IRQ_POLL IR_IGORPLUGUSB IR_IGUANA IR_IMON IR_IMON_RAW IR_MCEUSB IR_REDRAT3 IR_STREAMZAP IR_TOY IR_TTUSBIR ISA_BUS ISDN ISDN_CAPI_MIDDLEWARE JFFS2_CMODE_PRIORITY JFFS2_COMPRESSION_OPTIONS JFFS2_FS JFFS2_FS_POSIX_ACL JFFS2_FS_SECURITY JFFS2_FS_WRITEBUFFER JFFS2_FS_XATTR JFFS2_LZO JFFS2_RTIME JFFS2_RUBIN JFFS2_SUMMARY JFFS2_ZLIB JFS_DEBUG JFS_FS JFS_POSIX_ACL JFS_SECURITY JOYSTICK_IFORCE JOYSTICK_IFORCE_USB JOYSTICK_PXRC JOYSTICK_XPAD JOYSTICK_XPAD_FF JOYSTICK_XPAD_LEDS KARMA_PARTITION KCOV KCOV_ENABLE_COMPARISONS KCOV_INSTRUMENT_ALL KEYS_REQUEST_CACHE KEY_DH_OPERATIONS KEY_NOTIFICATIONS KSM KVM KVM_AMD KVM_ASYNC_PF KVM_COMPAT KVM_GENERIC_DIRTYLOG_READ_PROTECT KVM_MMIO KVM_VFIO KVM_XEN KVM_XFER_TO_GUEST_WORK L2TP L2TP_ETH L2TP_IP L2TP_V3 LAPB LAPBETHER LDM_PARTITION LEDS_TRIGGER_AUDIO LEGACY_PTYS LIBCRC32C LIBNVDIMM LINEAR_RANGES LLC LLC2 LOGIG940_FF LOGIRUMBLEPAD2_FF LOGO LOGO_LINUX_MONO LOGO_LINUX_VGA16 LPC_ICH LWTUNNEL LWTUNNEL_BPF LZ4HC_COMPRESS LZ4_COMPRESS MAC80211 MAC80211_DEBUGFS MAC80211_HAS_RC MAC80211_HWSIM MAC80211_MESH MAC80211_RC_DEFAULT_MINSTREL MAC80211_RC_MINSTREL MACSEC MACVLAN MACVTAP MAC_PARTITION MAPPING_DIRTY_HELPERS MDIO_MVUSB MD_LINEAR MD_MULTIPATH MD_RAID0 MD_RAID1 MD_RAID10 MD_RAID456 MEDIA_ANALOG_TV_SUPPORT MEDIA_ATTACH MEDIA_CONTROLLER MEDIA_CONTROLLER_DVB MEDIA_CONTROLLER_REQUEST_API MEDIA_DIGITAL_TV_SUPPORT MEDIA_RADIO_SUPPORT MEDIA_SDR_SUPPORT MEDIA_SUPPORT MEDIA_SUPPORT_FILTER MEDIA_TUNER MEDIA_TUNER_MSI001 MEMORY_BALLOON MEMORY_HOTPLUG MEMORY_HOTPLUG_DEFAULT_ONLINE MEMORY_ISOLATION MEMREGION MEMSTICK MEMSTICK_REALTEK_USB MEM_SOFT_DIRTY MFD_CORE MFD_SYSCON MHI_BUS MHI_WWAN_CTRL MHP_MEMMAP_ON_MEMORY MICROCHIP_PHY MINIX_FS MINIX_SUBPARTITION MISC_RTSX MISC_RTSX_USB MISDN MISDN_DSP MISDN_HFCUSB MISDN_L1OIP MITIGATION_TSA MKISS MLX4_CORE MLX4_INFINIBAND MMC MMC_REALTEK_USB MMC_USHC MMC_VUB300 MMU_NOTIFIER MODULE_SRCVERSION_ALL MODVERSIONS MOST MOST_USB_HDM MOUSE_APPLETOUCH MOUSE_BCM5974 MOUSE_PS2 MOUSE_PS2_ALPS MOUSE_PS2_BYD MOUSE_PS2_CYPRESS MOUSE_PS2_FOCALTECH MOUSE_PS2_LIFEBOOK MOUSE_PS2_LOGIPS2PP MOUSE_PS2_SMBUS MOUSE_PS2_SYNAPTICS MOUSE_PS2_SYNAPTICS_SMBUS MOUSE_PS2_TRACKPOINT MOUSE_SYNAPTICS_USB MPLS MPLS_IPTUNNEL MPLS_ROUTING MPTCP MPTCP_IPV6 MRP MTD MTD_BLKDEVS MTD_BLOCK MTD_BLOCK2MTD MTD_CFI_I1 MTD_CFI_I2 MTD_MAP_BANK_WIDTH_1 MTD_MAP_BANK_WIDTH_2 MTD_MAP_BANK_WIDTH_4 MTD_MTDRAM MTD_PHRAM MTD_SLRAM MUSB_PIO_ONLY ND_BTT ND_CLAIM ND_PFN NETDEVSIM NETFILTER_ADVANCED NETFILTER_FAMILY_ARP NETFILTER_FAMILY_BRIDGE NETFILTER_NETLINK_ACCT NETFILTER_NETLINK_GLUE_CT NETFILTER_NETLINK_OSF NETFILTER_NETLINK_QUEUE NETFILTER_SYNPROXY NETFILTER_XT_CONNMARK NETFILTER_XT_MATCH_BPF NETFILTER_XT_MATCH_CGROUP NETFILTER_XT_MATCH_CLUSTER NETFILTER_XT_MATCH_COMMENT NETFILTER_XT_MATCH_CONNBYTES NETFILTER_XT_MATCH_CONNLABEL NETFILTER_XT_MATCH_CONNLIMIT NETFILTER_XT_MATCH_CONNMARK NETFILTER_XT_MATCH_CPU NETFILTER_XT_MATCH_DCCP NETFILTER_XT_MATCH_DEVGROUP NETFILTER_XT_MATCH_DSCP NETFILTER_XT_MATCH_ECN NETFILTER_XT_MATCH_ESP NETFILTER_XT_MATCH_HASHLIMIT NETFILTER_XT_MATCH_HELPER NETFILTER_XT_MATCH_HL NETFILTER_XT_MATCH_IPCOMP NETFILTER_XT_MATCH_IPRANGE NETFILTER_XT_MATCH_IPVS NETFILTER_XT_MATCH_L2TP NETFILTER_XT_MATCH_LENGTH NETFILTER_XT_MATCH_LIMIT NETFILTER_XT_MATCH_MAC NETFILTER_XT_MATCH_MARK NETFILTER_XT_MATCH_MULTIPORT NETFILTER_XT_MATCH_NFACCT NETFILTER_XT_MATCH_OSF NETFILTER_XT_MATCH_OWNER NETFILTER_XT_MATCH_PHYSDEV NETFILTER_XT_MATCH_PKTTYPE NETFILTER_XT_MATCH_QUOTA NETFILTER_XT_MATCH_RATEEST NETFILTER_XT_MATCH_REALM NETFILTER_XT_MATCH_RECENT NETFILTER_XT_MATCH_SCTP NETFILTER_XT_MATCH_SOCKET NETFILTER_XT_MATCH_STATISTIC NETFILTER_XT_MATCH_STRING NETFILTER_XT_MATCH_TCPMSS NETFILTER_XT_MATCH_TIME NETFILTER_XT_MATCH_U32 NETFILTER_XT_SET NETFILTER_XT_TARGET_AUDIT NETFILTER_XT_TARGET_CHECKSUM NETFILTER_XT_TARGET_CLASSIFY NETFILTER_XT_TARGET_CONNMARK NETFILTER_XT_TARGET_CT NETFILTER_XT_TARGET_DSCP NETFILTER_XT_TARGET_HL NETFILTER_XT_TARGET_HMARK NETFILTER_XT_TARGET_IDLETIMER NETFILTER_XT_TARGET_LED NETFILTER_XT_TARGET_MARK NETFILTER_XT_TARGET_NETMAP NETFILTER_XT_TARGET_NFQUEUE NETFILTER_XT_TARGET_NOTRACK NETFILTER_XT_TARGET_RATEEST NETFILTER_XT_TARGET_REDIRECT NETFILTER_XT_TARGET_TCPOPTSTRIP NETFILTER_XT_TARGET_TEE NETFILTER_XT_TARGET_TPROXY NETFILTER_XT_TARGET_TRACE NETLABEL NETLINK_DIAG NETROM NET_9P_RDMA NET_ACT_BPF NET_ACT_CONNMARK NET_ACT_CSUM NET_ACT_CT NET_ACT_CTINFO NET_ACT_GATE NET_ACT_IFE NET_ACT_IPT NET_ACT_MPLS NET_ACT_NAT NET_ACT_PEDIT NET_ACT_POLICE NET_ACT_SAMPLE NET_ACT_SIMP NET_ACT_SKBEDIT NET_ACT_SKBMOD NET_ACT_TUNNEL_KEY NET_ACT_VLAN NET_CLS_BASIC NET_CLS_BPF NET_CLS_FLOW NET_CLS_FLOWER NET_CLS_FW NET_CLS_MATCHALL NET_CLS_ROUTE4 NET_DEVLINK NET_DROP_MONITOR NET_DSA NET_DSA_TAG_BRCM NET_DSA_TAG_BRCM_COMMON NET_DSA_TAG_BRCM_PREPEND NET_DSA_TAG_MTK NET_DSA_TAG_QCA NET_DSA_TAG_RTL4_A NET_EMATCH_CANID NET_EMATCH_CMP NET_EMATCH_IPSET NET_EMATCH_IPT NET_EMATCH_META NET_EMATCH_NBYTE NET_EMATCH_TEXT NET_EMATCH_U32 NET_FC NET_FOU NET_FOU_IP_TUNNELS NET_IFE NET_IFE_SKBMARK NET_IFE_SKBPRIO NET_IFE_SKBTCINDEX NET_IPGRE NET_IPGRE_BROADCAST NET_IPGRE_DEMUX NET_IPIP NET_IPVTI NET_KEY NET_KEY_MIGRATE NET_L3_MASTER_DEV NET_MPLS_GSO NET_NCSI NET_NSH NET_REDIRECT NET_SCH_CAKE NET_SCH_CBS NET_SCH_CHOKE NET_SCH_CODEL NET_SCH_DRR NET_SCH_ETF NET_SCH_ETS NET_SCH_FQ NET_SCH_FQ_CODEL NET_SCH_FQ_PIE NET_SCH_GRED NET_SCH_HFSC NET_SCH_HHF NET_SCH_HTB NET_SCH_INGRESS NET_SCH_MQPRIO NET_SCH_MULTIQ NET_SCH_NETEM NET_SCH_PIE NET_SCH_PLUG NET_SCH_PRIO NET_SCH_QFQ NET_SCH_RED NET_SCH_SFB NET_SCH_SFQ NET_SCH_SKBPRIO NET_SCH_TAPRIO NET_SCH_TBF NET_SCH_TEQL NET_SOCK_MSG NET_SWITCHDEV NET_TC_SKB_EXT NET_TEAM NET_TEAM_MODE_ACTIVEBACKUP NET_TEAM_MODE_BROADCAST NET_TEAM_MODE_LOADBALANCE NET_TEAM_MODE_RANDOM NET_TEAM_MODE_ROUNDROBIN NET_UDP_TUNNEL NET_VRF NFC NFC_DIGITAL NFC_FDP NFC_HCI NFC_MRVL NFC_MRVL_USB NFC_NCI NFC_NCI_UART NFC_PN533 NFC_PN533_USB NFC_PORT100 NFC_SHDLC NFC_SIM NFC_VIRTUAL_NCI NFSD NFSD_BLOCKLAYOUT NFSD_FLEXFILELAYOUT NFSD_PNFS NFSD_SCSILAYOUT NFSD_V3_ACL NFSD_V4 NFSD_V4_2_INTER_SSC NFSD_V4_SECURITY_LABEL NFS_FSCACHE NFS_V4_1 NFS_V4_2 NFS_V4_2_READ_PLUS NFS_V4_2_SSC_HELPER NFS_V4_SECURITY_LABEL NFT_BRIDGE_META NFT_BRIDGE_REJECT NFT_COMPAT NFT_CONNLIMIT NFT_CT NFT_DUP_IPV4 NFT_DUP_IPV6 NFT_DUP_NETDEV NFT_FIB NFT_FIB_INET NFT_FIB_IPV4 NFT_FIB_IPV6 NFT_FIB_NETDEV NFT_FLOW_OFFLOAD NFT_HASH NFT_LIMIT NFT_LOG NFT_MASQ NFT_NAT NFT_NUMGEN NFT_OSF NFT_QUEUE NFT_QUOTA NFT_REDIR NFT_REJECT NFT_REJECT_INET NFT_REJECT_IPV4 NFT_REJECT_IPV6 NFT_REJECT_NETDEV NFT_SOCKET NFT_SYNPROXY NFT_TPROXY NFT_TUNNEL NFT_XFRM NF_CONNTRACK_AMANDA NF_CONNTRACK_BRIDGE NF_CONNTRACK_BROADCAST NF_CONNTRACK_EVENTS NF_CONNTRACK_H323 NF_CONNTRACK_LABELS NF_CONNTRACK_MARK NF_CONNTRACK_NETBIOS_NS NF_CONNTRACK_PPTP NF_CONNTRACK_SANE NF_CONNTRACK_TFTP NF_CONNTRACK_TIMEOUT NF_CONNTRACK_TIMESTAMP NF_CONNTRACK_ZONES NF_CT_NETLINK_HELPER NF_CT_NETLINK_TIMEOUT NF_CT_PROTO_DCCP NF_CT_PROTO_GRE NF_CT_PROTO_SCTP NF_CT_PROTO_UDPLITE NF_DUP_IPV4 NF_DUP_IPV6 NF_FLOW_TABLE NF_TABLES NF_TABLES_BRIDGE NF_TABLES_INET NF_TABLES_IPV4 NF_TABLES_IPV6 NF_TABLES_NETDEV PARTITION_ADVANCED PSAMPLE RC_CORE RC_DEVICES RFKILL SPI USB_GADGET USB_MUSB_HDRC VIDEO_DEV WAN WATCH_QUEUE WIRELESS WLAN WWAN X25] disabling configs for [atomic_sleep hang memleak ubsan bug_or_warning kasan locking], they are not needed testing current HEAD 3594f306da129190de25938b823f353ef7f9e322 testing commit 3594f306da129190de25938b823f353ef7f9e322 gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: 179c6cf1d0d9c6e6856353443190fa9d97b740054ba742f0f4747544ca80eccb all runs: OK false negative chance: 0.000 # git bisect start 3594f306da129190de25938b823f353ef7f9e322 dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 Bisecting: 85 revisions left to test after this (roughly 7 steps) [59614c5acf6688f7af3c245d359082c0e9e53117] vhost-scsi: protect vq->log_used with vq->mutex determine whether the revision contains the guilty commit revision dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 crashed and is reachable testing commit 59614c5acf6688f7af3c245d359082c0e9e53117 gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: e3c4a63056dfd91822ee7c3540354c14f745fff22e606d4d8e728bbe73ccef88 all runs: OK false negative chance: 0.000 # git bisect bad 59614c5acf6688f7af3c245d359082c0e9e53117 Bisecting: 42 revisions left to test after this (roughly 5 steps) [27fc2b31d4d1b2e8eb7a2e5b50e2d24b73116e89] smb: server: make use of rdma_destroy_qp() determine whether the revision contains the guilty commit revision dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 crashed and is reachable testing commit 27fc2b31d4d1b2e8eb7a2e5b50e2d24b73116e89 gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: 4dd8f78e5a8e234560db2daaf099db4df41db767209a0d763a7ba7187f25995b all runs: OK false negative chance: 0.000 # git bisect bad 27fc2b31d4d1b2e8eb7a2e5b50e2d24b73116e89 Bisecting: 20 revisions left to test after this (roughly 4 steps) [d69cd64bd5af41c6fd409313504089970edaf02f] maple_tree: fix MA_STATE_PREALLOC flag in mas_preallocate() determine whether the revision contains the guilty commit revision dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 crashed and is reachable testing commit d69cd64bd5af41c6fd409313504089970edaf02f gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: 249926a09d513ae95a0005b373f042b2cc50c24c55ed196cb176bc9612cb286f all runs: OK false negative chance: 0.000 # git bisect bad d69cd64bd5af41c6fd409313504089970edaf02f Bisecting: 10 revisions left to test after this (roughly 3 steps) [1dbf7cd2454a28b1da700085b99346b5445aeabb] tipc: Fix use-after-free in tipc_conn_close(). determine whether the revision contains the guilty commit revision dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 crashed and is reachable testing commit 1dbf7cd2454a28b1da700085b99346b5445aeabb gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: 9fc48e233690f67841bf13cccaf4c826a53f736bfe6926f9a9f87c93899bc28c all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify representative crash: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify, types: [NULL-POINTER-DEREFERENCE] # git bisect good 1dbf7cd2454a28b1da700085b99346b5445aeabb Bisecting: 5 revisions left to test after this (roughly 3 steps) [d823d21de698098dcac18023fcb3e1e546c54553] net: phy: smsc: Fix link failure in forced mode with Auto-MDIX determine whether the revision contains the guilty commit revision dfc486ec9cce9eaaeb72cca8fcf04cd1ed230905 crashed and is reachable testing commit d823d21de698098dcac18023fcb3e1e546c54553 gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: 5e1abe5b6e993010bb1eec26e598f27e23aa893a6e90c8d1330d16dc56958072 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify representative crash: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify, types: [NULL-POINTER-DEREFERENCE] # git bisect good d823d21de698098dcac18023fcb3e1e546c54553 Bisecting: 2 revisions left to test after this (roughly 2 steps) [1579a2777cb914a249de22c789ba4d41b154509f] atm: clip: Fix infinite recursive call of clip_push(). determine whether the revision contains the guilty commit revision 1dbf7cd2454a28b1da700085b99346b5445aeabb crashed and is reachable testing commit 1579a2777cb914a249de22c789ba4d41b154509f gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: ba8f1fac389b97d252d88317f7fa8aa9f0830b4f522bae7c9f84746e11fa8183 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify representative crash: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify, types: [NULL-POINTER-DEREFERENCE] # git bisect good 1579a2777cb914a249de22c789ba4d41b154509f Bisecting: 0 revisions left to test after this (roughly 1 step) [23c165dde88eac405eebb59051ea1fe139a45803] net/sched: Abort __tc_modify_qdisc if parent class does not exist determine whether the revision contains the guilty commit revision 1dbf7cd2454a28b1da700085b99346b5445aeabb crashed and is reachable testing commit 23c165dde88eac405eebb59051ea1fe139a45803 gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: 9c1d7ab9d280a1a5e91805e797c4068f2e7f5ee42c8b7038e84d32d3626e2264 all runs: OK false negative chance: 0.000 # git bisect bad 23c165dde88eac405eebb59051ea1fe139a45803 Bisecting: 0 revisions left to test after this (roughly 0 steps) [27b5bb7ea1a8fa7b8c4cfde4d2bf8650cca2e8e8] atm: clip: Fix NULL pointer dereference in vcc_sendmsg() determine whether the revision contains the guilty commit revision d823d21de698098dcac18023fcb3e1e546c54553 crashed and is reachable testing commit 27b5bb7ea1a8fa7b8c4cfde4d2bf8650cca2e8e8 gcc compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 kernel signature: c272a36ec528e187f4aae4e5ee2978e0c0ac6e0c8c38d64f11e819577c522dc3 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify representative crash: BUG: unable to handle kernel NULL pointer dereference in htb_qlen_notify, types: [NULL-POINTER-DEREFERENCE] # git bisect good 27b5bb7ea1a8fa7b8c4cfde4d2bf8650cca2e8e8 23c165dde88eac405eebb59051ea1fe139a45803 is the first bad commit commit 23c165dde88eac405eebb59051ea1fe139a45803 Author: Victor Nogueira Date: Mon Jul 7 18:08:01 2025 -0300 net/sched: Abort __tc_modify_qdisc if parent class does not exist [ Upstream commit ffdde7bf5a439aaa1955ebd581f5c64ab1533963 ] Lion's patch [1] revealed an ancient bug in the qdisc API. Whenever a user creates/modifies a qdisc specifying as a parent another qdisc, the qdisc API will, during grafting, detect that the user is not trying to attach to a class and reject. However grafting is performed after qdisc_create (and thus the qdiscs' init callback) is executed. In qdiscs that eventually call qdisc_tree_reduce_backlog during init or change (such as fq, hhf, choke, etc), an issue arises. For example, executing the following commands: sudo tc qdisc add dev lo root handle a: htb default 2 sudo tc qdisc add dev lo parent a: handle beef fq Qdiscs such as fq, hhf, choke, etc unconditionally invoke qdisc_tree_reduce_backlog() in their control path init() or change() which then causes a failure to find the child class; however, that does not stop the unconditional invocation of the assumed child qdisc's qlen_notify with a null class. All these qdiscs make the assumption that class is non-null. The solution is ensure that qdisc_leaf() which looks up the parent class, and is invoked prior to qdisc_create(), should return failure on not finding the class. In this patch, we leverage qdisc_leaf to return ERR_PTRs whenever the parentid doesn't correspond to a class, so that we can detect it earlier on and abort before qdisc_create is called. [1] https://lore.kernel.org/netdev/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.com/ Fixes: 5e50da01d0ce ("[NET_SCHED]: Fix endless loops (part 2): "simple" qdiscs") Reported-by: syzbot+d8b58d7b0ad89a678a16@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/68663c93.a70a0220.5d25f.0857.GAE@google.com/ Reported-by: syzbot+5eccb463fa89309d8bdc@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/68663c94.a70a0220.5d25f.0858.GAE@google.com/ Reported-by: syzbot+1261670bbdefc5485a06@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/686764a5.a00a0220.c7b3.0013.GAE@google.com/ Reported-by: syzbot+15b96fc3aac35468fe77@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/686764a5.a00a0220.c7b3.0014.GAE@google.com/ Reported-by: syzbot+4dadc5aecf80324d5a51@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/68679e81.a70a0220.29cf51.0016.GAE@google.com/ Acked-by: Jamal Hadi Salim Reviewed-by: Cong Wang Signed-off-by: Victor Nogueira Link: https://patch.msgid.link/20250707210801.372995-1-victor@mojatatu.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin net/sched/sch_api.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) accumulated error probability: 0.00 culprit signature: 9c1d7ab9d280a1a5e91805e797c4068f2e7f5ee42c8b7038e84d32d3626e2264 parent signature: c272a36ec528e187f4aae4e5ee2978e0c0ac6e0c8c38d64f11e819577c522dc3 revisions tested: 16, total time: 3h55m22.931797365s (build: 1h39m11.798517437s, test: 2h9m26.641700215s) first good commit: 23c165dde88eac405eebb59051ea1fe139a45803 net/sched: Abort __tc_modify_qdisc if parent class does not exist recipients (to): ["jhs@mojatatu.com" "kuba@kernel.org" "sashal@kernel.org" "victor@mojatatu.com" "xiyou.wangcong@gmail.com"] recipients (cc): []