ci2 starts bisection 2026-09-18 19:22:30.6324706 +0000 UTC m=+44602.009145503
bisecting fixing commit since 3aa1dcaa4f6f5ae08936491e08bd456f331f2d40
building syzkaller on b13552fed1cdc2826f57a5741df12ca67130314a
ensuring issue is reproducible on original commit 3aa1dcaa4f6f5ae08936491e08bd456f331f2d40

testing commit 3aa1dcaa4f6f5ae08936491e08bd456f331f2d40 gcc
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
kernel signature: 900bce535bf45245b5b4e895f79b8513edf12dca5f1fa122613bea32fa38b696
run #0: crashed: KASAN: slab-use-after-free Write in release_tty
run #1: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #2: crashed: KASAN: slab-use-after-free Write in release_tty
run #3: crashed: KASAN: slab-use-after-free Write in release_tty
run #4: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #5: crashed: KASAN: slab-use-after-free Write in release_tty
run #6: crashed: KASAN: slab-use-after-free Write in release_tty
run #7: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #8: crashed: KASAN: slab-use-after-free Write in release_tty
run #9: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #10: crashed: KASAN: slab-use-after-free Write in tty_init_dev
run #11: crashed: KASAN: slab-use-after-free Write in release_tty
run #12: crashed: KASAN: slab-use-after-free Write in tty_init_dev
run #13: crashed: KASAN: slab-use-after-free Write in release_tty
run #14: crashed: KASAN: slab-use-after-free Write in tty_init_dev
run #15: crashed: KASAN: slab-use-after-free Write in release_tty
run #16: crashed: KASAN: slab-use-after-free Write in release_tty
run #17: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #18: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #19: crashed: general protection fault in gs_close
representative crash: KASAN: slab-use-after-free Write in release_tty, types: [KASAN-USE-AFTER-FREE-WRITE 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 3aa1dcaa4f6f5ae08936491e08bd456f331f2d40 gcc
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
kernel signature: 830efd5c3bd909eb83701a0a85194f516d7a96143bae091d0cb554b1250f9810
run #0: crashed: KASAN: slab-use-after-free Write in release_tty
run #1: crashed: KASAN: slab-use-after-free Write in release_tty
run #2: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #3: crashed: KASAN: slab-use-after-free Write in release_tty
run #4: crashed: KASAN: slab-use-after-free Write in release_tty
run #5: crashed: KASAN: slab-use-after-free Write in release_tty
run #6: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #7: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #8: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #9: crashed: KASAN: slab-use-after-free Read in check_tty_count
representative crash: KASAN: slab-use-after-free Write in release_tty, types: [KASAN-USE-AFTER-FREE-WRITE KASAN-USE-AFTER-FREE-READ]
the bug reproduces without the instrumentation
disabling configs for [bug_or_warning locking atomic_sleep hang memleak ubsan], they are not needed
kconfig minimization: base=4167 full=8398 leaves diff=2094
split chunks (needed=false): <2094>
split chunk #0 of len 2094 into 5 parts
testing without sub-chunk 1/5
disabling configs for [bug_or_warning locking atomic_sleep hang memleak ubsan], they are not needed
testing commit 3aa1dcaa4f6f5ae08936491e08bd456f331f2d40 gcc
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
kernel signature: d9ee8fea28adc501f930b6f01243196f476d108e2d388bb0326f3a4f17f68f3a
run #0: crashed: KASAN: slab-use-after-free in release_tty
run #1: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #2: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #3: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #4: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #5: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #6: crashed: KASAN: slab-use-after-free Write in release_tty
run #7: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #8: crashed: KASAN: slab-use-after-free Write in release_tty
run #9: crashed: KASAN: slab-use-after-free Read in check_tty_count
representative crash: KASAN: slab-use-after-free Read in check_tty_count, types: [KASAN-USE-AFTER-FREE-READ KASAN-USE-AFTER-FREE-WRITE]
the chunk can be dropped
testing without sub-chunk 2/5
disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed
testing commit 3aa1dcaa4f6f5ae08936491e08bd456f331f2d40 gcc
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
kernel signature: ad40947fe42e67c42ad49170b2dc4a3b6ff71810c928f3bd5541e44b9c418785
run #0: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #1: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #2: crashed: KASAN: slab-use-after-free Write in release_tty
run #3: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #4: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #5: crashed: KASAN: slab-use-after-free Write in release_tty
run #6: crashed: KASAN: slab-use-after-free Write in release_tty
run #7: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #8: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #9: crashed: KASAN: slab-use-after-free Write in release_tty
representative crash: KASAN: slab-use-after-free Read in check_tty_count, types: [KASAN-USE-AFTER-FREE-READ KASAN-USE-AFTER-FREE-WRITE]
the chunk can be dropped
testing without sub-chunk 3/5
disabling configs for [bug_or_warning locking atomic_sleep hang memleak ubsan], they are not needed
testing commit 3aa1dcaa4f6f5ae08936491e08bd456f331f2d40 gcc
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
kernel signature: 418324239820a8a726ef576dc603f90d48d2518cf8f81993f2e2b3ae05fb46c0
all runs: crashed: KASAN: slab-use-after-free Read in check_tty_count
representative crash: KASAN: slab-use-after-free Read in check_tty_count, types: [KASAN-USE-AFTER-FREE-READ]
the chunk can be dropped
testing without sub-chunk 4/5
disabling configs for [atomic_sleep hang memleak ubsan bug_or_warning locking], they are not needed
testing commit 3aa1dcaa4f6f5ae08936491e08bd456f331f2d40 gcc
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
kernel signature: b0ffa8ea80ac40b55362aac29b54638b066b36b0afe9b4377c3f0524f7c4c8fc
all runs: crashed: KASAN: slab-use-after-free Read in check_tty_count
representative crash: KASAN: slab-use-after-free Read in check_tty_count, 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 3aa1dcaa4f6f5ae08936491e08bd456f331f2d40 gcc
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
kernel signature: a81571bc8b4fa0b3948dfb6c98de98dddb2b98506e61c4bcc3db1ce4bcb39a9f
all runs: OK
false negative chance: 0.000
minimized to 418 configs; suspects: [ATM BCMA BLK_DEV_ZONED BPF_SYSCALL CARDBUS CFG80211 CFG80211_WEXT COMMON_CLK CONTIG_ALLOC DVB_CORE EXTCON GPIOLIB HID_ZEROPLUS I2C_MUX IIO IOMMUFD 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_CDNS3 USB_CDNSP_PCI USB_CDNS_SUPPORT USB_CHAOSKEY USB_CHIPIDEA USB_CHIPIDEA_GENERIC USB_CHIPIDEA_HOST USB_CHIPIDEA_MSM USB_CHIPIDEA_NPCM USB_CHIPIDEA_PCI USB_CHIPIDEA_UDC USB_CONFIGFS USB_CONFIGFS_ACM USB_CONFIGFS_ECM USB_CONFIGFS_ECM_SUBSET USB_CONFIGFS_EEM USB_CONFIGFS_F_FS USB_CONFIGFS_F_HID USB_CONFIGFS_F_LB_SS USB_CONFIGFS_F_MIDI USB_CONFIGFS_F_MIDI2 USB_CONFIGFS_F_PRINTER USB_CONFIGFS_F_TCM USB_CONFIGFS_F_UAC1 USB_CONFIGFS_F_UAC1_LEGACY USB_CONFIGFS_F_UAC2 USB_CONFIGFS_F_UVC USB_CONFIGFS_MASS_STORAGE USB_CONFIGFS_NCM USB_CONFIGFS_OBEX USB_CONFIGFS_PHONET USB_CONFIGFS_RNDIS USB_CONFIGFS_SERIAL USB_CONN_GPIO USB_CXACRU USB_CYPRESS_CY7C63 USB_CYTHERM USB_DSBR USB_DUMMY_HCD USB_DWC2 USB_DWC2_HOST USB_DWC2_PCI USB_DWC3 USB_DWC3_GADGET USB_DWC3_GENERIC_PLAT USB_DWC3_HAPS USB_DWC3_OF_SIMPLE USB_DWC3_PCI USB_DWC3_ULPI USB_DYNAMIC_MINORS USB_EG20T USB_EHCI_FSL USB_EHCI_HCD_PLATFORM USB_EHCI_ROOT_HUB_TT USB_EHSET_TEST_FIXTURE USB_EMI26 USB_EMI62 USB_EPSON2888 USB_EZUSB_FX2 USB_FEW_INIT_RETRIES USB_F_ACM USB_F_ECM USB_F_EEM USB_F_FS USB_F_HID USB_F_MASS_STORAGE USB_F_MIDI USB_F_MIDI2 USB_F_NCM USB_F_OBEX USB_F_PHONET USB_F_PRINTER USB_F_RNDIS USB_F_SERIAL USB_F_SS_LB USB_F_SUBSET USB_F_TCM USB_F_UAC1 USB_F_UAC1_LEGACY USB_F_UAC2 USB_F_UVC USB_GADGET USB_GADGETFS USB_GADGET_DEBUG_FILES USB_GADGET_DEBUG_FS USB_GL860 USB_GOKU USB_GR_UDC USB_GSPCA USB_GSPCA_BENQ USB_GSPCA_CONEX USB_GSPCA_CPIA1 USB_GSPCA_DTCS033 USB_GSPCA_ETOMS USB_GSPCA_FINEPIX USB_GSPCA_JEILINJ USB_GSPCA_JL2005BCD USB_GSPCA_KINECT USB_GSPCA_KONICA USB_GSPCA_MARS USB_GSPCA_MR97310A USB_GSPCA_NW80X USB_GSPCA_OV519 USB_GSPCA_OV534 USB_GSPCA_OV534_9 USB_GSPCA_PAC207 USB_GSPCA_PAC7302 USB_GSPCA_PAC7311 USB_GSPCA_SE401 USB_GSPCA_SN9C2028 USB_GSPCA_SN9C20X USB_GSPCA_SONIXB USB_GSPCA_SONIXJ USB_GSPCA_SPCA1528 USB_GSPCA_SPCA500 USB_GSPCA_SPCA501 USB_GSPCA_SPCA505 USB_GSPCA_SPCA506 USB_GSPCA_SPCA508 USB_GSPCA_SPCA561 USB_GSPCA_SQ905 USB_GSPCA_SQ905C USB_GSPCA_SQ930X USB_GSPCA_STK014 USB_GSPCA_STK1135 USB_GSPCA_STV0680 USB_GSPCA_SUNPLUS USB_GSPCA_T613 USB_GSPCA_TOPRO USB_GSPCA_TOUPTEK USB_GSPCA_TV8532 USB_GSPCA_VC032X USB_GSPCA_VICAM USB_GSPCA_XIRLINK_CIT USB_GSPCA_ZC3XX USB_HACKRF USB_HCD_BCMA USB_HCD_SSB USB_HSIC_USB3503 USB_HSIC_USB4604 USB_HSO USB_HUB_USB251XB USB_IDMOUSE USB_IOWARRIOR USB_IPHETH USB_ISIGHTFW USB_ISP116X_HCD USB_ISP1301 USB_ISP1760 USB_ISP1760_DUAL_ROLE USB_ISP1760_HCD USB_ISP1761_UDC USB_KAWETH USB_KC2190 USB_KEENE USB_LAN78XX USB_LCD USB_LD USB_LEDS_TRIGGER_USBPORT USB_LED_TRIG USB_LEGOTOWER USB_LGM_PHY USB_LIBCOMPOSITE USB_LINK_LAYER_TEST USB_M5602 USB_MA901 USB_MAX3420_UDC USB_MAX3421_HCD USB_MDC800 USB_MICROTEK USB_MR800 USB_MSI2500 USB_MUSB_DUAL_ROLE USB_MUSB_HDRC USB_NET2280 USB_NET_AQC111 USB_NET_AX88179_178A USB_NET_AX8817X USB_NET_CDCETHER USB_NET_CDC_EEM USB_NET_CDC_MBIM USB_NET_CDC_NCM USB_NET_CDC_SUBSET USB_NET_CDC_SUBSET_ENABLE USB_NET_CH9200 USB_NET_CX82310_ETH USB_NET_DM9601 USB_NET_GL620A USB_NET_HUAWEI_CDC_NCM USB_NET_INT51X1 USB_NET_KALMIA USB_NET_MCS7830 USB_NET_NET1080 USB_NET_PLUSB USB_NET_QMI_WWAN USB_NET_RNDIS_HOST USB_NET_SMSC75XX USB_NET_SMSC95XX USB_NET_SR9700 USB_NET_SR9800 USB_NET_ZAURUS USB_OHCI_HCD_PLATFORM USB_OTG USB_OTG_FSM USB_OXU210HP_HCD USB_PEGASUS USB_PULSE8_CEC USB_PWC USB_PWC_INPUT_EVDEV USB_PXA27X USB_R8A66597 USB_R8A66597_HCD USB_RAINSHADOW_CEC USB_RAREMONO USB_RAW_GADGET USB_RTL8150 USB_RTL8152 USB_RTL8153_ECM USB_S2255 USB_SERIAL USB_SERIAL_AIRCABLE USB_SERIAL_ARK3116 USB_SERIAL_BELKIN USB_SERIAL_CH341 USB_SERIAL_CONSOLE USB_SERIAL_CP210X USB_SERIAL_CYBERJACK USB_SERIAL_CYPRESS_M8 USB_SERIAL_DEBUG USB_SERIAL_DIGI_ACCELEPORT USB_SERIAL_EDGEPORT USB_SERIAL_EDGEPORT_TI USB_SERIAL_EMPEG USB_SERIAL_F81232 USB_SERIAL_F8153X USB_SERIAL_FTDI_SIO USB_SERIAL_GARMIN USB_SERIAL_GENERIC USB_SERIAL_IPAQ USB_SERIAL_IPW USB_SERIAL_IR USB_SERIAL_IUU USB_SERIAL_KEYSPAN USB_SERIAL_KEYSPAN_PDA USB_SERIAL_KLSI USB_SERIAL_KOBIL_SCT USB_SERIAL_MCT_U232 USB_SERIAL_METRO USB_SERIAL_MOS7715_PARPORT USB_SERIAL_MOS7720 USB_SERIAL_MOS7840 USB_SERIAL_MXUPORT USB_SERIAL_NAVMAN USB_SERIAL_OMNINET USB_SERIAL_OPTICON USB_SERIAL_OPTION USB_SERIAL_OTI6858 USB_SERIAL_PL2303 USB_SERIAL_QCAUX USB_SERIAL_QT2 USB_SERIAL_QUALCOMM USB_SERIAL_SAFE USB_SERIAL_SIERRAWIRELESS USB_SERIAL_SIMPLE USB_SERIAL_SPCP8X5 USB_SERIAL_SSU100 USB_SERIAL_SYMBOL USB_SERIAL_TI USB_SERIAL_UPD78F0730 USB_SERIAL_VISOR USB_SERIAL_WHITEHEAT USB_SERIAL_WISHBONE USB_SERIAL_WWAN USB_SERIAL_XR USB_SERIAL_XSENS_MT USB_SEVSEG USB_SI470X USB_SI4713 USB_SIERRA_NET USB_SISUSBVGA USB_SL811_CS USB_SL811_HCD USB_SL811_HCD_ISO USB_SNP_CORE USB_SPEEDTOUCH USB_STORAGE_ALAUDA USB_STORAGE_CYPRESS_ATACB USB_STORAGE_DATAFAB USB_STORAGE_ENE_UB6250 USB_STORAGE_FREECOM USB_STORAGE_ISD200 USB_STORAGE_JUMPSHOT USB_STORAGE_KARMA USB_STORAGE_ONETOUCH USB_STORAGE_SDDR09 USB_STORAGE_SDDR55 USB_STORAGE_USBAT USB_STV06XX USB_TEST USB_TMC USB_TRANCEVIBRATOR USB_UAS USB_UEAGLEATM USB_ULPI_BUS USB_USBNET USB_USS720 USB_U_AUDIO USB_U_ETHER USB_U_SERIAL USB_VIDEO_CLASS USB_VIDEO_CLASS_INPUT_EVDEV USB_VL600 USB_WDM USB_XHCI_DBGCAP USB_XHCI_PCI_RENESAS USB_XHCI_PLATFORM USB_XUSBATM USB_YUREX USERFAULTFD USERIO USER_RETURN_NOTIFIER UVC_COMMON U_SERIAL_CONSOLE V4L2_MEM2MEM_DEV V4L_TEST_DRIVERS VALIDATE_FS_PARSER VDPA VDPA_SIM VDPA_SIM_BLOCK VDPA_SIM_NET VETH VFIO VFIO_DEVICE_CDEV VFIO_PCI VFIO_PCI_CORE VFIO_PCI_INTX VFIO_VIRQFD VGASTATE VHOST VHOST_CROSS_ENDIAN_LEGACY VHOST_IOTLB VHOST_NET VHOST_RING VHOST_TASK VHOST_VDPA VHOST_VSOCK VIDEO VIDEOBUF2_CORE VIDEOBUF2_DMA_CONTIG VIDEOBUF2_DMA_SG VIDEOBUF2_MEMOPS VIDEOBUF2_V4L2 VIDEOBUF2_VMALLOC VIDEOMODE_HELPERS VIDEO_AU0828 VIDEO_AU0828_RC VIDEO_AU0828_V4L2 VIDEO_CS53L32A VIDEO_CX231XX VIDEO_CX231XX_ALSA VIDEO_CX231XX_DVB VIDEO_CX231XX_RC VIDEO_CX2341X VIDEO_CX25840 VIDEO_DEV VIDEO_EM28XX VIDEO_EM28XX_ALSA VIDEO_EM28XX_DVB VIDEO_EM28XX_RC VIDEO_EM28XX_V4L2 VIDEO_GO7007 VIDEO_GO7007_LOADER VIDEO_GO7007_USB VIDEO_GO7007_USB_S2250_BOARD VIDEO_HDPVR VIDEO_MSP3400 VIDEO_PVRUSB2 VIDEO_PVRUSB2_DVB VIDEO_PVRUSB2_SYSFS VIDEO_SAA711X VIDEO_STK1160 VIDEO_TUNER VIDEO_TVEEPROM VIDEO_USBTV VIDEO_V4L2_I2C VIDEO_V4L2_SUBDEV_API VIDEO_V4L2_TPG VIDEO_VICODEC VIDEO_VIM2M VIDEO_VIMC VIDEO_VIVID VIDEO_VIVID_CEC VIDEO_WM8775 VIPERBOARD_ADC VIRTIO_BALLOON VIRTIO_DMA_SHARED_BUFFER VIRTIO_MEM VIRTIO_MMIO VIRTIO_MMIO_CMDLINE_DEVICES VIRTIO_PMEM VIRTIO_VDPA VIRTIO_VSOCKETS VIRTIO_VSOCKETS_COMMON VIRT_WIFI VIRT_XFER_TO_GUEST_WORK VLAN_8021Q VLAN_8021Q_GVRP VLAN_8021Q_MVRP VMWARE_VMCI VMXNET3 VP_VDPA VSOCKETS VSOCKETS_DIAG VSOCKETS_LOOPBACK VSOCKMON VT_HW_CONSOLE_BINDING WANT_DEV_COREDUMP WEXT_CORE WEXT_PROC WIREGUARD WIRELESS WLAN WLAN_VENDOR_ADMTEK WLAN_VENDOR_SILABS X86_FRED X86_SGX X86_SGX_KVM X86_USER_SHADOW_STACK XDP_SOCKETS XDP_SOCKETS_DIAG XFRM_ESPINTCP XFRM_INTERFACE XFRM_IPCOMP XFRM_MIGRATE XFRM_OFFLOAD XFRM_STATISTICS XFRM_SUB_POLICY XFRM_USER_COMPAT XFS_BTREE_IN_MEM XFS_DRAIN_INTENTS XFS_FS XFS_LIVE_HOOKS XFS_MEMORY_BUFS XFS_ONLINE_REPAIR XFS_ONLINE_SCRUB XFS_POSIX_ACL XFS_QUOTA XFS_RT XILLYBUS_CLASS XILLYUSB XOR_BLOCKS XOR_BLOCKS_ARCH YENTA YENTA_ENE_TUNE YENTA_O2 YENTA_RICOH YENTA_TI YENTA_TOSHIBA ZEROPLUS_FF ZLIB_DEFLATE ZONEFS_FS ZRAM ZRAM_BACKEND_FORCE_LZO ZRAM_BACKEND_LZO ZRAM_DEF_COMP_LZO ZSMALLOC ZSTD_COMPRESS ZSWAP ZSWAP_COMPRESSOR_DEFAULT_842 ZSWAP_DEFAULT_ON ZSWAP_SHRINKER_DEFAULT_ON]
disabling configs for [memleak ubsan bug_or_warning locking atomic_sleep hang], they are not needed
testing current HEAD ef31d04b6d8adfc971fc6b9ff76a1d6dc9aeefab
testing commit ef31d04b6d8adfc971fc6b9ff76a1d6dc9aeefab gcc
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
kernel signature: 26656208c9976c67d95530467a70cd73a31e69106b82b795f3ecbc7a9fdbc4e4
run #0: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #1: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #2: crashed: KASAN: slab-use-after-free Read in tty_open
run #3: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #4: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #5: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #6: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #7: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #8: crashed: KASAN: slab-use-after-free Read in check_tty_count
run #9: crashed: KASAN: slab-use-after-free Read in check_tty_count
representative crash: KASAN: slab-use-after-free Read in check_tty_count, types: [KASAN-USE-AFTER-FREE-READ]
crash still not fixed/happens on the oldest tested release
revisions tested: 8, total time: 2h32m5.3874828s (build: 59m30.0011719s, test: 1h6m50.230499733s)
crash still not fixed or there were kernel test errors
commit msg: Merge tag 'pci-v7.3-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci
crash: KASAN: slab-use-after-free Read in check_tty_count
=========================================
==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:82 [inline]
BUG: KASAN: slab-use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: slab-use-after-free in tty_port_kopened include/linux/tty_port.h:234 [inline]
BUG: KASAN: slab-use-after-free in check_tty_count+0x140/0x2a0 drivers/tty/tty_io.c:287
Read of size 8 at addr ffff888124932230 by task syz.6.20/4749

CPU: 1 UID: 0 PID: 4749 Comm: syz.6.20 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x52/0x80 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200
 instrument_atomic_read include/linux/instrumented.h:82 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 tty_port_kopened include/linux/tty_port.h:234 [inline]
 check_tty_count+0x140/0x2a0 drivers/tty/tty_io.c:287
 tty_release+0x79/0x12c0 drivers/tty/tty_io.c:1701
 __fput+0x2fd/0x780 fs/file_table.c:512
 task_work_run+0x151/0x1f0 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x12f/0x540 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
 do_syscall_64+0x1b3/0x370 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f387a3de0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe53b75988 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f387a667da0 RCX: 00007f387a3de0d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f387a667da0 R08: 00007f387a666038 R09: 0000000000000000
R10: 000000000003fda0 R11: 0000000000000246 R12: 000000000001549d
R13: 00007f387a665fac R14: 00000000000151b4 R15: 00007ffe53b75a90
 </TASK>

Allocated by task 4750:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x2e9/0x580 mm/slub.c:5563
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 gs_port_alloc drivers/usb/gadget/function/u_serial.c:1218 [inline]
 gserial_alloc_line_no_console+0x1fa/0x690 drivers/usb/gadget/function/u_serial.c:1298
 gserial_alloc_line+0xe/0x60 drivers/usb/gadget/function/u_serial.c:1332
 acm_alloc_instance+0xc2/0x120 drivers/usb/gadget/function/f_acm.c:891
 try_get_usb_function_instance drivers/usb/gadget/functions.c:28 [inline]
 usb_get_function_instance+0xe2/0x2a0 drivers/usb/gadget/functions.c:44
 function_make+0x10f/0x320 drivers/usb/gadget/configfs.c:626
 configfs_mkdir+0x46f/0x8c0 fs/configfs/dir.c:1369
 vfs_mkdir+0x34b/0x520 fs/namei.c:5410
 filename_mkdirat+0x232/0x450 fs/namei.c:5443
 __do_sys_mkdirat fs/namei.c:5464 [inline]
 __se_sys_mkdirat fs/namei.c:5461 [inline]
 __x64_sys_mkdirat+0x8a/0x160 fs/namei.c:5461
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0xca/0x370 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 4750:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6508 [inline]
 kfree+0x1ad/0x520 mm/slub.c:6801
 gserial_free_port+0x1de/0x250 drivers/usb/gadget/function/u_serial.c:1262
 gserial_free_line+0x93/0xc0 drivers/usb/gadget/function/u_serial.c:1279
 acm_free_instance+0x34/0x60 drivers/usb/gadget/function/f_acm.c:875
 usb_put_function_instance+0x8b/0xb0 drivers/usb/gadget/functions.c:77
 config_item_cleanup fs/configfs/item.c:128 [inline]
 config_item_release+0x101/0x200 fs/configfs/item.c:137
 configfs_rmdir+0x774/0x820 fs/configfs/dir.c:1580
 vfs_rmdir+0x1ca/0x550 fs/namei.c:5515
 filename_rmdir+0x243/0x470 fs/namei.c:5572
 __do_sys_rmdir fs/namei.c:5595 [inline]
 __se_sys_rmdir fs/namei.c:5592 [inline]
 __x64_sys_rmdir+0x51/0x120 fs/namei.c:5592
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0xca/0x370 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888124932000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 560 bytes inside of
 freed 2048-byte region [ffff888124932000, ffff888124932800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x124930
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x200000000000040(head|node=0|zone=2)
page_type: f5(slab)
raw: 0200000000000040 ffff888100042000 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 0200000000000040 ffff888100042000 dead000000000100 dead000000000122
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 0200000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1805, tgid 1805 (kworker/u8:10), ts 86450572313
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x112/0x140 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x2984/0x2a00 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x28b/0x560 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab+0x7c/0x570 mm/slub.c:3462
 new_slab mm/slub.c:3513 [inline]
 refill_objects+0x33f/0x3b0 mm/slub.c:7417
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x25d/0x520 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __do_kmalloc_node mm/slub.c:5413 [inline]
 __kmalloc_node_track_caller_noprof+0x4f2/0x690 mm/slub.c:5545
 kmalloc_reserve net/core/skbuff.c:637 [inline]
 __alloc_skb+0x1e5/0x5e0 net/core/skbuff.c:715
 alloc_skb include/linux/skbuff.h:1384 [inline]
 mld_newpack+0x148/0x920 net/ipv6/mcast.c:1810
 add_grhead net/ipv6/mcast.c:1921 [inline]
 add_grec+0xbd8/0xfd0 net/ipv6/mcast.c:2060
 mld_send_initial_cr net/ipv6/mcast.c:2305 [inline]
 ipv6_mc_dad_complete+0x2be/0x7e0 net/ipv6/mcast.c:2316
 addrconf_dad_completed+0x480/0xa90 net/ipv6/addrconf.c:4376
 addrconf_dad_work+0xbfb/0x12a0 net/ipv6/addrconf.c:-1
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xa3d/0x1620 kernel/workqueue.c:3479
 worker_thread+0x807/0xc40 kernel/workqueue.c:3560
 kthread+0x297/0x340 kernel/kthread.c:436
page last free pid 38 tgid 38 ts 86311861285 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 free_pages_prepare+0x9c3/0xab0 mm/page_alloc.c:1463
 __free_contig_range_common+0x166/0x310 mm/page_alloc.c:7072
 __free_contig_range mm/page_alloc.c:7117 [inline]
 free_pages_bulk+0x48/0x110 mm/page_alloc.c:5322
 vm_area_free_pages mm/vmalloc.c:3461 [inline]
 vfree+0x1ba/0x370 mm/vmalloc.c:3510
 delayed_vfree_work+0x3c/0x70 mm/vmalloc.c:3414
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xa3d/0x1620 kernel/workqueue.c:3479
 worker_thread+0x807/0xc40 kernel/workqueue.c:3560
 kthread+0x297/0x340 kernel/kthread.c:436
 ret_from_fork+0x29c/0x620 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:
 ffff888124932100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888124932180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888124932200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff888124932280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888124932300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================