Extracting prog: 5m19.692317101s
Minimizing prog: 18m11.903249873s
Simplifying prog options: 3m46.379937252s
Extracting C: 57.881626826s
Simplifying C: 0s


extracting reproducer from 1 programs
testing a last program of every proc
single: executing 1 programs separately with timeout 6m0s
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: INFO: task hung in bdev_open
single: successfully extracted reproducer
found reproducer with 5 syscalls
minimizing guilty program
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_DO_IT(r0, 0xab03)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080))
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
ioctl$NBD_SET_SOCK(r0, 0xab00, 0xffffffffffffffff)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r0=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(0xffffffffffffffff, 0xab00, r0)
ioctl$NBD_SET_SIZE_BLOCKS(0xffffffffffffffff, 0xab07, 0x4)
ioctl$NBD_DO_IT(0xffffffffffffffff, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(0x0, 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, 0x0)
ioctl$NBD_SET_SOCK(r0, 0xab00, 0xffffffffffffffff)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
program did not crash
simplifying guilty program options
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
validation run: crashed=false
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
validation run: crashed=false
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
validation run: crashed=false
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
validation run: crashed=false
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: INFO: task hung in bdev_open
validation run: crashed=true
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
validation run: crashed=false
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
validation run: crashed=false
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
validation run: crashed=false
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: INFO: task hung in bdev_open
validation run: crashed=true
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_SET_SIZE_BLOCKS-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x2)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0x4)
ioctl$NBD_DO_IT(r0, 0xab03)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
validation run: crashed=false
reproducing took 51m33.57353481s
repro crashed as (corrupted=false):
INFO: task udevd:4693 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:20520 pid:4693  tgid:4693  ppid:1      task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 bdev_open+0xde/0xd70 block/bdev.c:990
 blkdev_open+0x461/0x600 block/fops.c:674
 do_dentry_open+0x816/0x1380 fs/open.c:996
 vfs_open+0x3b/0x340 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x1443/0x1d60 fs/namei.c:5000
 do_file_open+0x23e/0x4a0 fs/namei.c:5029
 do_sys_openat2+0x115/0x200 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_openat fs/open.c:1439 [inline]
 __se_sys_openat fs/open.c:1434 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1434
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f34a14a7407
RSP: 002b:00007ffe50dd6f50 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f34a1cb3880 RCX: 00007f34a14a7407
RDX: 00000000000a0800 RSI: 00005651ac0b6ad0 RDI: ffffffffffffff9c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 000056517d131100 R14: 0000000000000000 R15: 00007ffe50dd71e0
 </TASK>
INFO: task syz.0.18:5671 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.18        state:D stack:28032 pid:5671  tgid:5670  ppid:5419   task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 bdev_release+0x1b8/0x690 block/bdev.c:1173
 blkdev_release+0x15/0x20 block/fops.c:682
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 get_signal+0x1181/0x12c0 kernel/signal.c:2884
 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x10e/0x770 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+0x328/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7b6719e159
RSP: 002b:00007f7b68103028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f7b67425fa0 RCX: 00007f7b6719e159
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f7b6723506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7b67426038 R14: 00007f7b67425fa0 R15: 00007fffa9d5af88
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/26: 1, last CPU#0:
 #0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/u5:0/46: 2, on CPU#0:
 #0: ffff888000eb4140 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff888000eb4140 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff888000eb4140 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff888000eb4140 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc900008a7c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc900008a7c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc900008a7c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc900008a7c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by kworker/u5:1/4643: 2, on CPU#0:
 #0: ffff88803568c940 ((wq_completion)nbd6-recv){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88803568c940 ((wq_completion)nbd6-recv){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88803568c940 ((wq_completion)nbd6-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88803568c940 ((wq_completion)nbd6-recv){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc9000f367c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9000f367c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9000f367c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc9000f367c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by udevd/4693: 1, on CPU#0:
 #0: ffff888000ecb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by getty/5083: 2, on CPU#0:
 #0: ffff88803fa570a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90000e802e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/u5:2/5312: 2, on CPU#0:
 #0: ffff888000a25140 ((wq_completion)nbd3-recv){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff888000a25140 ((wq_completion)nbd3-recv){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff888000a25140 ((wq_completion)nbd3-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff888000a25140 ((wq_completion)nbd3-recv){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc9000dd47c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9000dd47c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9000dd47c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc9000dd47c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by udevd/5431: 1, on CPU#0:
 #0: ffff888000ecb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by kworker/u5:3/5434: 2, on CPU#0:
 #0: ffff8880355cc940 ((wq_completion)nbd5-recv){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff8880355cc940 ((wq_completion)nbd5-recv){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff8880355cc940 ((wq_completion)nbd5-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff8880355cc940 ((wq_completion)nbd5-recv){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc900052afc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc900052afc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc900052afc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc900052afc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by syz.0.18/5671: 1, on CPU#0:
 #0: ffff888000ecb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1b8/0x690 block/bdev.c:1173
locks held by kworker/u5:4/5715: 2, on CPU#0:
 #0: ffff888000e97140 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff888000e97140 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff888000e97140 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff888000e97140 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc9000799fc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9000799fc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9000799fc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc9000799fc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by kworker/u5:5/5718: 2, on CPU#0:
 #0: ffff8880355cf140 ((wq_completion)nbd4-recv){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff8880355cf140 ((wq_completion)nbd4-recv){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff8880355cf140 ((wq_completion)nbd4-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff8880355cf140 ((wq_completion)nbd4-recv){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc900079cfc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc900079cfc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc900079cfc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc900079cfc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 26 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

final repro crashed as (corrupted=false):
INFO: task udevd:4693 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:20520 pid:4693  tgid:4693  ppid:1      task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 bdev_open+0xde/0xd70 block/bdev.c:990
 blkdev_open+0x461/0x600 block/fops.c:674
 do_dentry_open+0x816/0x1380 fs/open.c:996
 vfs_open+0x3b/0x340 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x1443/0x1d60 fs/namei.c:5000
 do_file_open+0x23e/0x4a0 fs/namei.c:5029
 do_sys_openat2+0x115/0x200 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_openat fs/open.c:1439 [inline]
 __se_sys_openat fs/open.c:1434 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1434
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f34a14a7407
RSP: 002b:00007ffe50dd6f50 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f34a1cb3880 RCX: 00007f34a14a7407
RDX: 00000000000a0800 RSI: 00005651ac0b6ad0 RDI: ffffffffffffff9c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 000056517d131100 R14: 0000000000000000 R15: 00007ffe50dd71e0
 </TASK>
INFO: task syz.0.18:5671 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.18        state:D stack:28032 pid:5671  tgid:5670  ppid:5419   task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 bdev_release+0x1b8/0x690 block/bdev.c:1173
 blkdev_release+0x15/0x20 block/fops.c:682
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 get_signal+0x1181/0x12c0 kernel/signal.c:2884
 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x10e/0x770 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+0x328/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7b6719e159
RSP: 002b:00007f7b68103028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f7b67425fa0 RCX: 00007f7b6719e159
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f7b6723506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7b67426038 R14: 00007f7b67425fa0 R15: 00007fffa9d5af88
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/26: 1, last CPU#0:
 #0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/u5:0/46: 2, on CPU#0:
 #0: ffff888000eb4140 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff888000eb4140 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff888000eb4140 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff888000eb4140 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc900008a7c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc900008a7c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc900008a7c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc900008a7c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by kworker/u5:1/4643: 2, on CPU#0:
 #0: ffff88803568c940 ((wq_completion)nbd6-recv){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88803568c940 ((wq_completion)nbd6-recv){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88803568c940 ((wq_completion)nbd6-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88803568c940 ((wq_completion)nbd6-recv){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc9000f367c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9000f367c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9000f367c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc9000f367c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by udevd/4693: 1, on CPU#0:
 #0: ffff888000ecb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by getty/5083: 2, on CPU#0:
 #0: ffff88803fa570a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90000e802e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/u5:2/5312: 2, on CPU#0:
 #0: ffff888000a25140 ((wq_completion)nbd3-recv){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff888000a25140 ((wq_completion)nbd3-recv){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff888000a25140 ((wq_completion)nbd3-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff888000a25140 ((wq_completion)nbd3-recv){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc9000dd47c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9000dd47c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9000dd47c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc9000dd47c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by udevd/5431: 1, on CPU#0:
 #0: ffff888000ecb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by kworker/u5:3/5434: 2, on CPU#0:
 #0: ffff8880355cc940 ((wq_completion)nbd5-recv){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff8880355cc940 ((wq_completion)nbd5-recv){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff8880355cc940 ((wq_completion)nbd5-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff8880355cc940 ((wq_completion)nbd5-recv){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc900052afc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc900052afc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc900052afc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc900052afc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by syz.0.18/5671: 1, on CPU#0:
 #0: ffff888000ecb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1b8/0x690 block/bdev.c:1173
locks held by kworker/u5:4/5715: 2, on CPU#0:
 #0: ffff888000e97140 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff888000e97140 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff888000e97140 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff888000e97140 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc9000799fc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9000799fc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9000799fc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc9000799fc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by kworker/u5:5/5718: 2, on CPU#0:
 #0: ffff8880355cf140 ((wq_completion)nbd4-recv){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff8880355cf140 ((wq_completion)nbd4-recv){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff8880355cf140 ((wq_completion)nbd4-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff8880355cf140 ((wq_completion)nbd4-recv){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc900079cfc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc900079cfc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc900079cfc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc900079cfc40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 26 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>