Extracting prog: 1m10.112452203s
Minimizing prog: 10m20.761079159s
Simplifying prog options: 2m21.532419691s
Extracting C: 26.460779175s
Simplifying C: 0s
extracting reproducer from 24 programs
first checking the prog from the crash report
single: executing 1 programs separately with timeout 30s
testing program (duration=30s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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}}): ioctl$VIDIOC_S_TUNER-syz_open_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
ioctl$VIDIOC_S_TUNER(0xffffffffffffffff, 0x4054561e, 0x0)
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program crashed: possible deadlock in blkg_conf_prep
single: successfully extracted reproducer
found reproducer with 7 syscalls
minimizing guilty program
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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}}): ioctl$VIDIOC_S_TUNER-syz_open_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int
detailed listing:
executing program 0:
ioctl$VIDIOC_S_TUNER(0xffffffffffffffff, 0x4054561e, 0x0)
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
program did not crash
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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}}): ioctl$VIDIOC_S_TUNER-syz_open_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-write$cgroup_subtree
detailed listing:
executing program 0:
ioctl$VIDIOC_S_TUNER(0xffffffffffffffff, 0x4054561e, 0x0)
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
write$cgroup_subtree(0xffffffffffffffff, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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}}): ioctl$VIDIOC_S_TUNER-syz_open_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
ioctl$VIDIOC_S_TUNER(0xffffffffffffffff, 0x4054561e, 0x0)
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_int(0xffffffffffffffff, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r1, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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}}): ioctl$VIDIOC_S_TUNER-syz_open_procfs-preadv-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
ioctl$VIDIOC_S_TUNER(0xffffffffffffffff, 0x4054561e, 0x0)
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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}}): ioctl$VIDIOC_S_TUNER-syz_open_procfs-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
ioctl$VIDIOC_S_TUNER(0xffffffffffffffff, 0x4054561e, 0x0)
syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r0 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r1 = openat$cgroup_int(r0, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r1, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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}}): ioctl$VIDIOC_S_TUNER-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
ioctl$VIDIOC_S_TUNER(0xffffffffffffffff, 0x4054561e, 0x0)
preadv(0xffffffffffffffff, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r0 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r1 = openat$cgroup_int(r0, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r1, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program crashed: possible deadlock in blkg_conf_prep
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, 0x0)
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, 0x0, 0x0, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{0x0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, 0x0, 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, 0x0, 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, 0x0, 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, 0x0, 0x6a)
program did not crash
extracting C reproducer
testing compiled C program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
program did not crash
simplifying guilty program options
testing program (duration=37.334751597s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
testing program (duration=37.334751597s, {Threaded:true Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
testing program (duration=37.334751597s, {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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
validation run: crashed=false
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
validation run: crashed=false
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program crashed: possible deadlock in blkg_conf_prep
validation run: crashed=true
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program crashed: possible deadlock in blkg_conf_prep
validation run: crashed=true
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program did not crash
validation run: crashed=false
testing program (duration=37.334751597s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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_procfs-preadv-mkdirat$cgroup_root-openat$cgroup_root-openat$cgroup_int-write$cgroup_subtree
detailed listing:
executing program 0:
r0 = syz_open_procfs(0x0, &(0x7f0000000140)='net/fib_triestat\x00')
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000040)=""/208, 0xd0}], 0x1, 0x2a, 0xd)
mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff)
r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0)
r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0)
write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a)
program crashed: possible deadlock in blkg_conf_prep
validation run: crashed=true
reproducing took 18m23.606238071s
repro crashed as (corrupted=false):
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.3.20/6039 is trying to acquire lock:
ffffffff8efc6c00 (fs_reclaim
){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:314 [inline]
){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4539 [inline]
){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:4899 [inline]
){+.+.}-{0:0}, at: kmem_cache_alloc_noprof+0x63/0x6a0 mm/slub.c:4933
but task is already holding lock:
ffff888028bae100 (&q->blkcg_mutex){+.+.}-{4:4}, at: blkg_conf_prep+0xbc/0xf10 block/blk-cgroup.c:849
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&q->blkcg_mutex){+.+.}-{4:4}
:
lock_acquire kernel/locking/lockdep.c:5886 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5843
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x1a4/0x1bc0 kernel/locking/mutex.c:821
blkcg_activate_policy+0x34f/0xbf0 block/blk-cgroup.c:1608
blk_throtl_init+0x39a/0x5b0 block/blk-throttle.c:1339
tg_set_conf.isra.0+0x252/0x500 block/blk-throttle.c:1368
cgroup_file_write+0x1e6/0x8a0 kernel/cgroup/cgroup.c:4412
kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6af/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (&q->q_usage_counter(io)#2){++++}-{0:0}:
lock_acquire kernel/locking/lockdep.c:5886 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5843
blk_alloc_queue+0x610/0x790 block/blk-core.c:504
__blk_alloc_disk+0xa0/0x170 block/genhd.c:1520
brd_alloc.isra.0+0x41a/0x820 drivers/block/brd.c:327
brd_init+0x167/0x190 drivers/block/brd.c:420
do_one_initcall+0x11c/0x6f0 init/main.c:1353
do_initcall_level init/main.c:1415 [inline]
do_initcalls init/main.c:1431 [inline]
do_basic_setup init/main.c:1451 [inline]
kernel_init_freeable+0x6ea/0x7b0 init/main.c:1666
kernel_init+0x21/0x1e0 init/main.c:1556
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
-> #0 (fs_reclaim){+.+.}-{0:0}:
check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3181
check_prevs_add kernel/locking/lockdep.c:3300 [inline]
validate_chain kernel/locking/lockdep.c:3924 [inline]
__lock_acquire+0x1492/0x1ec0 kernel/locking/lockdep.c:5253
lock_acquire kernel/locking/lockdep.c:5886 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5843
__fs_reclaim_acquire mm/page_alloc.c:4375 [inline]
fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4389
might_alloc include/linux/sched/mm.h:314 [inline]
slab_pre_alloc_hook mm/slub.c:4539 [inline]
slab_alloc_node mm/slub.c:4899 [inline]
kmem_cache_alloc_noprof+0x63/0x6a0 mm/slub.c:4933
__radix_tree_preload+0x333/0x820 lib/radix-tree.c:338
blkg_conf_prep+0x489/0xf10 block/blk-cgroup.c:885
tg_set_conf.isra.0+0x1ed/0x500 block/blk-throttle.c:1373
cgroup_file_write+0x1e6/0x8a0 kernel/cgroup/cgroup.c:4412
kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6af/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
fs_reclaim --> &q->q_usage_counter(io)#2 --> &q->blkcg_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&q->blkcg_mutex);
lock(&q->q_usage_counter(io)#2);
lock(&q->blkcg_mutex);
lock(fs_reclaim);
*** DEADLOCK ***
locks held by syz.3.20/6039: 6, last CPU#3:
#0: ffff88802339cd30 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff888037ab0460 (sb_writers#11){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#2: ffff88802f2bbc80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:336
#3: ffff88802a08a5a8 (kn->active#66){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#3: ffff88802a08a5a8 (kn->active#66){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:337
#4: ffff888028badf80 (&q->rq_qos_mutex){+.+.}-{4:4}, at: blkg_conf_open_bdev+0x253/0x410 block/blk-cgroup.c:806
#5: ffff888028bae100 (&q->blkcg_mutex){+.+.}-{4:4}, at: blkg_conf_prep+0xbc/0xf10 block/blk-cgroup.c:849
stack backtrace:
CPU: 3 UID: 0 PID: 6039 Comm: syz.3.20 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:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_circular_bug.cold+0x178/0x1be kernel/locking/lockdep.c:2059
check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2191
check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3181
check_prevs_add kernel/locking/lockdep.c:3300 [inline]
validate_chain kernel/locking/lockdep.c:3924 [inline]
__lock_acquire+0x1492/0x1ec0 kernel/locking/lockdep.c:5253
lock_acquire kernel/locking/lockdep.c:5886 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5843
__fs_reclaim_acquire mm/page_alloc.c:4375 [inline]
fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4389
might_alloc include/linux/sched/mm.h:314 [inline]
slab_pre_alloc_hook mm/slub.c:4539 [inline]
slab_alloc_node mm/slub.c:4899 [inline]
kmem_cache_alloc_noprof+0x63/0x6a0 mm/slub.c:4933
__radix_tree_preload+0x333/0x820 lib/radix-tree.c:338
blkg_conf_prep+0x489/0xf10 block/blk-cgroup.c:885
tg_set_conf.isra.0+0x1ed/0x500 block/blk-throttle.c:1373
cgroup_file_write+0x1e6/0x8a0 kernel/cgroup/cgroup.c:4412
kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6af/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f87a939e0d9
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:00007f87aa1ff028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f87a9625fa0 RCX: 00007f87a939e0d9
RDX: 000000000000006a RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007f87a9435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f87a9626038 R14: 00007f87a9625fa0 R15: 00007ffd6065d3e8
final repro crashed as (corrupted=false):
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.3.20/6039 is trying to acquire lock:
ffffffff8efc6c00 (fs_reclaim
){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:314 [inline]
){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4539 [inline]
){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:4899 [inline]
){+.+.}-{0:0}, at: kmem_cache_alloc_noprof+0x63/0x6a0 mm/slub.c:4933
but task is already holding lock:
ffff888028bae100 (&q->blkcg_mutex){+.+.}-{4:4}, at: blkg_conf_prep+0xbc/0xf10 block/blk-cgroup.c:849
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&q->blkcg_mutex){+.+.}-{4:4}
:
lock_acquire kernel/locking/lockdep.c:5886 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5843
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x1a4/0x1bc0 kernel/locking/mutex.c:821
blkcg_activate_policy+0x34f/0xbf0 block/blk-cgroup.c:1608
blk_throtl_init+0x39a/0x5b0 block/blk-throttle.c:1339
tg_set_conf.isra.0+0x252/0x500 block/blk-throttle.c:1368
cgroup_file_write+0x1e6/0x8a0 kernel/cgroup/cgroup.c:4412
kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6af/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (&q->q_usage_counter(io)#2){++++}-{0:0}:
lock_acquire kernel/locking/lockdep.c:5886 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5843
blk_alloc_queue+0x610/0x790 block/blk-core.c:504
__blk_alloc_disk+0xa0/0x170 block/genhd.c:1520
brd_alloc.isra.0+0x41a/0x820 drivers/block/brd.c:327
brd_init+0x167/0x190 drivers/block/brd.c:420
do_one_initcall+0x11c/0x6f0 init/main.c:1353
do_initcall_level init/main.c:1415 [inline]
do_initcalls init/main.c:1431 [inline]
do_basic_setup init/main.c:1451 [inline]
kernel_init_freeable+0x6ea/0x7b0 init/main.c:1666
kernel_init+0x21/0x1e0 init/main.c:1556
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
-> #0 (fs_reclaim){+.+.}-{0:0}:
check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3181
check_prevs_add kernel/locking/lockdep.c:3300 [inline]
validate_chain kernel/locking/lockdep.c:3924 [inline]
__lock_acquire+0x1492/0x1ec0 kernel/locking/lockdep.c:5253
lock_acquire kernel/locking/lockdep.c:5886 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5843
__fs_reclaim_acquire mm/page_alloc.c:4375 [inline]
fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4389
might_alloc include/linux/sched/mm.h:314 [inline]
slab_pre_alloc_hook mm/slub.c:4539 [inline]
slab_alloc_node mm/slub.c:4899 [inline]
kmem_cache_alloc_noprof+0x63/0x6a0 mm/slub.c:4933
__radix_tree_preload+0x333/0x820 lib/radix-tree.c:338
blkg_conf_prep+0x489/0xf10 block/blk-cgroup.c:885
tg_set_conf.isra.0+0x1ed/0x500 block/blk-throttle.c:1373
cgroup_file_write+0x1e6/0x8a0 kernel/cgroup/cgroup.c:4412
kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6af/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
fs_reclaim --> &q->q_usage_counter(io)#2 --> &q->blkcg_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&q->blkcg_mutex);
lock(&q->q_usage_counter(io)#2);
lock(&q->blkcg_mutex);
lock(fs_reclaim);
*** DEADLOCK ***
locks held by syz.3.20/6039: 6, last CPU#3:
#0: ffff88802339cd30 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff888037ab0460 (sb_writers#11){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#2: ffff88802f2bbc80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:336
#3: ffff88802a08a5a8 (kn->active#66){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#3: ffff88802a08a5a8 (kn->active#66){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:337
#4: ffff888028badf80 (&q->rq_qos_mutex){+.+.}-{4:4}, at: blkg_conf_open_bdev+0x253/0x410 block/blk-cgroup.c:806
#5: ffff888028bae100 (&q->blkcg_mutex){+.+.}-{4:4}, at: blkg_conf_prep+0xbc/0xf10 block/blk-cgroup.c:849
stack backtrace:
CPU: 3 UID: 0 PID: 6039 Comm: syz.3.20 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:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_circular_bug.cold+0x178/0x1be kernel/locking/lockdep.c:2059
check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2191
check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3181
check_prevs_add kernel/locking/lockdep.c:3300 [inline]
validate_chain kernel/locking/lockdep.c:3924 [inline]
__lock_acquire+0x1492/0x1ec0 kernel/locking/lockdep.c:5253
lock_acquire kernel/locking/lockdep.c:5886 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5843
__fs_reclaim_acquire mm/page_alloc.c:4375 [inline]
fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4389
might_alloc include/linux/sched/mm.h:314 [inline]
slab_pre_alloc_hook mm/slub.c:4539 [inline]
slab_alloc_node mm/slub.c:4899 [inline]
kmem_cache_alloc_noprof+0x63/0x6a0 mm/slub.c:4933
__radix_tree_preload+0x333/0x820 lib/radix-tree.c:338
blkg_conf_prep+0x489/0xf10 block/blk-cgroup.c:885
tg_set_conf.isra.0+0x1ed/0x500 block/blk-throttle.c:1373
cgroup_file_write+0x1e6/0x8a0 kernel/cgroup/cgroup.c:4412
kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6af/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f87a939e0d9
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:00007f87aa1ff028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f87a9625fa0 RCX: 00007f87a939e0d9
RDX: 000000000000006a RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007f87a9435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f87a9626038 R14: 00007f87a9625fa0 R15: 00007ffd6065d3e8