ci starts bisection 2026-01-14 00:17:00.005528523 +0000 UTC m=+4191409.531014655
bisecting fixing commit since e53642b87a4f4b03a8d7e5f8507fc3cd0c595ea6
building syzkaller on fd2207e7cf691493b5b81c50a8a625b4b71dd544
ensuring issue is reproducible on original commit e53642b87a4f4b03a8d7e5f8507fc3cd0c595ea6
testing commit e53642b87a4f4b03a8d7e5f8507fc3cd0c595ea6 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: a6621a46ff4872237264da0338c72c21044eb26bed50e66d49734e1c78571239
all runs: crashed: INFO: task hung in __vhost_worker_flush
representative crash: INFO: task hung in __vhost_worker_flush, types: [HANG]
check whether we can drop unnecessary instrumentation
disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed
testing commit e53642b87a4f4b03a8d7e5f8507fc3cd0c595ea6 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: e7dd1992cca01147517af02235244dc1ada7c1b5ba51bb592feb1ba79da0fa26
all runs: crashed: INFO: task hung in __vhost_worker_flush
representative crash: INFO: task hung in __vhost_worker_flush, types: [HANG]
the bug reproduces without the instrumentation
disabling configs for [atomic_sleep memleak ubsan bug_or_warning kasan locking], they are not needed
kconfig minimization: base=4109 full=8336 leaves diff=2116
split chunks (needed=false): <2116>
split chunk #0 of len 2116 into 5 parts
testing without sub-chunk 1/5
disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed
testing commit e53642b87a4f4b03a8d7e5f8507fc3cd0c595ea6 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: b729e141e4fe3240659a22a56f61fd9019477fc02551215cece336938c17ff95
all runs: crashed: INFO: task hung in __vhost_worker_flush
representative crash: INFO: task hung in __vhost_worker_flush, types: [HANG]
the chunk can be dropped
testing without sub-chunk 2/5
disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed
testing commit e53642b87a4f4b03a8d7e5f8507fc3cd0c595ea6 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 571066ca70bb38ab973f18e6315a389c92660d7fc00eda9eec9523fdaa8e19ad
all runs: crashed: INFO: task hung in __vhost_worker_flush
representative crash: INFO: task hung in __vhost_worker_flush, types: [HANG]
the chunk can be dropped
testing without sub-chunk 3/5
disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed
testing commit e53642b87a4f4b03a8d7e5f8507fc3cd0c595ea6 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 5ec40eaeb622a6676eb2e9b38f9bb6f50853484c04249796fb8b11c9456b6dea
all runs: crashed: INFO: task hung in __vhost_worker_flush
representative crash: INFO: task hung in __vhost_worker_flush, types: [HANG]
the chunk can be dropped
testing without sub-chunk 4/5
disabling configs for [ubsan bug_or_warning kasan locking atomic_sleep memleak], they are not needed
testing commit e53642b87a4f4b03a8d7e5f8507fc3cd0c595ea6 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: a47de6191edaafcdb566871d444dd27e3ece19633303dcb2ab257ebce5f7b9bd
all runs: crashed: INFO: task hung in __vhost_worker_flush
representative crash: INFO: task hung in __vhost_worker_flush, types: [HANG]
the chunk can be dropped
testing without sub-chunk 5/5
disabling configs for [kasan locking atomic_sleep memleak ubsan bug_or_warning], they are not needed
testing commit e53642b87a4f4b03a8d7e5f8507fc3cd0c595ea6 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: ef7ca7ba49f1e02176a2f3c83c0d5251211eff3061ec8762cc4a8256d8219bda
all runs: OK
false negative chance: 0.000
minimized to 420 configs; suspects: [ARCH_ENABLE_MEMORY_HOTREMOVE ATM BCMA BLK_DEV_ZONED BPF_SYSCALL CARDBUS CFG80211 CFG80211_WEXT CMA COMMON_CLK CONTIG_ALLOC DVB_CORE EXTCON GPIOLIB HID_ZEROPLUS I2C_MUX IIO IOMMUFD IRQ_REMAP KVM KVM_INTEL LIBNVDIMM MEDIA_ANALOG_TV_SUPPORT MEDIA_CAMERA_SUPPORT MEDIA_CEC_SUPPORT MEDIA_CONTROLLER MEDIA_DIGITAL_TV_SUPPORT MEDIA_RADIO_SUPPORT MEDIA_SDR_SUPPORT MEDIA_SUPPORT MEDIA_TEST_SUPPORT MEDIA_USB_SUPPORT MEMORY_HOTPLUG MEMORY_HOTREMOVE MFD_VIPERBOARD NOP_USB_XCEIV PARPORT PCCARD PCMCIA PHONET RADIO_ADAPTERS RADIO_SI470X RADIO_SI4713 RC_CORE RFKILL SND SOUND SPI SSB TAP TARGET_CORE TUN USB_AMD5536UDC USB_ATM USB_CDNS2_UDC USB_CDNS3 USB_CDNS3_GADGET USB_CDNS3_HOST USB_CDNS3_PCI_WRAP USB_CDNSP_GADGET USB_CDNSP_HOST USB_CDNSP_PCI USB_CDNS_HOST USB_CDNS_SUPPORT USB_CHAOSKEY USB_CHIPIDEA USB_CHIPIDEA_GENERIC USB_CHIPIDEA_HOST USB_CHIPIDEA_MSM USB_CHIPIDEA_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 VXFS_FS 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_FS XFS_POSIX_ACL XFS_QUOTA XFS_RT XILLYBUS_CLASS XILLYUSB XOR_BLOCKS 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 [locking atomic_sleep memleak ubsan bug_or_warning kasan], they are not needed
testing current HEAD b54345928fa1dbde534e32ecaa138678fd5d2135
testing commit b54345928fa1dbde534e32ecaa138678fd5d2135 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: f9965ce9937893d3deafb4a1ff91386a8f434551b9873b81a21c3ec2cc810a66
all runs: crashed: INFO: task hung in __vhost_worker_flush
representative crash: INFO: task hung in __vhost_worker_flush, types: [HANG]
crash still not fixed/happens on the oldest tested release
revisions tested: 8, total time: 5h41m55.840245106s (build: 4h5m20.792456684s, test: 57m14.038543548s)
crash still not fixed or there were kernel test errors
commit msg: Merge tag 'gfs2-for-6.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
crash: INFO: task hung in __vhost_worker_flush
INFO: task syz.2.17:3846 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.17 state:D stack:13024 pid:3846 tgid:3846 ppid:3618 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x946/0xe40 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xac/0x140 kernel/sched/core.c:6960
schedule_timeout+0x2c/0x160 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common+0xfa/0x1e0 kernel/sched/completion.c:132
__vhost_worker_flush+0x125/0x170 drivers/vhost/vhost.c:296
vhost_worker_flush drivers/vhost/vhost.c:303 [inline]
vhost_dev_flush+0x66/0xc0 drivers/vhost/vhost.c:313
vhost_vsock_flush drivers/vhost/vsock.c:701 [inline]
vhost_vsock_dev_release+0xd8/0x180 drivers/vhost/vsock.c:759
__fput+0x105/0x290 fs/file_table.c:468
task_work_run+0x87/0xb0 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:44 [inline]
exit_to_user_mode_loop+0xd0/0x4b0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x188/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f839f47efc9
RSP: 002b:00007ffc2d3e0188 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f839f6d7da0 RCX: 00007f839f47efc9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f839f6d7da0 R08: 0000000000000000 R09: 000000082d3e047f
R10: 00007f839f6d7cb0 R11: 0000000000000246 R12: 000000000000f6b0
R13: 00007ffc2d3e0280 R14: ffffffffffffffff R15: 00007ffc2d3e02a0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff83790920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff83790920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff83790920 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x2e/0x100 kernel/locking/lockdep.c:6775
2 locks held by getty/2722:
#0: ffff8881036c60a0 (&tty->ldisc_sem){....}-{0:0}, at: tty_ldisc_ref_wait+0x20/0x40 drivers/tty/tty_ldisc.c:243
#1: ffffc90008ccf2f0 (&ldata->atomic_read_lock){....}-{3:3}, at: n_tty_read+0x1c4/0x700 drivers/tty/n_tty.c:2211
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(none)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x52/0x80 lib/dump_stack.c:120
nmi_cpu_backtrace+0xbb/0x110 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x8e/0x140 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x95/0xb0 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0x590/0x5b0 kernel/hung_task.c:515
kthread+0x203/0x230 kernel/kthread.c:463
ret_from_fork+0x146/0x280 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(none)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 03 26 01 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 23 be 10 00 f3 0f 1e fa fb f4 d8 25 01 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff83603e88 EFLAGS: 000002c2
RAX: ffff8882b36ed000 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 00000000ffffe021 RSI: ffffffff83204033 RDI: ffffffff83358e0f
RBP: 000001f3fffffc18 R08: 0000000000080000 R09: 0000000000000072
R10: 0000000000000000 R11: ffffffff813195d0 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff83624940 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8882b36ed000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558bbac4a8 CR3: 000000000365c000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x3c/0x60 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0xda/0x240 kernel/sched/idle.c:332
cpu_startup_entry+0x25/0x30 kernel/sched/idle.c:430
rest_init+0xca/0xd0 init/main.c:757
start_kernel+0x2d8/0x2f0 init/main.c:1206
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0xfc/0x100 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147