Extracting prog: 7m59.336858722s Minimizing prog: 1h13m16.061439987s Simplifying prog options: 9m4.00906279s Extracting C: 3m46.904501811s 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}}): socket$nl_netfilter-sendmsg$NFT_BATCH-socket$inet-sendto$inet detailed listing: executing program 0: r0 = socket$nl_netfilter(0x10, 0x3, 0xc) sendmsg$NFT_BATCH(r0, &(0x7f0000000080)={0x0, 0x0, &(0x7f0000000040)={&(0x7f0000000600)=ANY=[@ANYBLOB="140000001000010000000000000000000000000a20000000000a010300000000000000000100fffd0900010073797a300000000040000000030a01020000000000000000010000000900030073797a3200000000140004800800024032658aeb08000140000000010900010073797a300000000044000000060a010400000000000001040100000008000b40000000000900010073797a30000000001c000480180001800d00010073796e70726f7879000000000400028014000000110001"], 0xcc}, 0x1, 0x0, 0x0, 0x40000}, 0x0) r1 = socket$inet(0x2, 0x4000000000000001, 0x0) sendto$inet(r1, 0x0, 0x0, 0x200007fd, &(0x7f0000e68000)={0x2, 0x4e23, @local}, 0x10) program crashed: INFO: task hung in tun_chr_close single: successfully extracted reproducer found reproducer with 4 syscalls minimizing guilty program testing program (duration=7m58.835192883s, {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}}): socket$nl_netfilter-sendmsg$NFT_BATCH-socket$inet detailed listing: executing program 0: r0 = socket$nl_netfilter(0x10, 0x3, 0xc) sendmsg$NFT_BATCH(r0, &(0x7f0000000080)={0x0, 0x0, &(0x7f0000000040)={&(0x7f0000000600)=ANY=[@ANYBLOB="140000001000010000000000000000000000000a20000000000a010300000000000000000100fffd0900010073797a300000000040000000030a01020000000000000000010000000900030073797a3200000000140004800800024032658aeb08000140000000010900010073797a300000000044000000060a010400000000000001040100000008000b40000000000900010073797a30000000001c000480180001800d00010073796e70726f7879000000000400028014000000110001"], 0xcc}, 0x1, 0x0, 0x0, 0x40000}, 0x0) socket$inet(0x2, 0x4000000000000001, 0x0) program did not crash testing program (duration=7m58.835192883s, {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}}): socket$nl_netfilter-sendmsg$NFT_BATCH-sendto$inet detailed listing: executing program 0: r0 = socket$nl_netfilter(0x10, 0x3, 0xc) sendmsg$NFT_BATCH(r0, &(0x7f0000000080)={0x0, 0x0, &(0x7f0000000040)={&(0x7f0000000600)=ANY=[@ANYBLOB="140000001000010000000000000000000000000a20000000000a010300000000000000000100fffd0900010073797a300000000040000000030a01020000000000000000010000000900030073797a3200000000140004800800024032658aeb08000140000000010900010073797a300000000044000000060a010400000000000001040100000008000b40000000000900010073797a30000000001c000480180001800d00010073796e70726f7879000000000400028014000000110001"], 0xcc}, 0x1, 0x0, 0x0, 0x40000}, 0x0) sendto$inet(0xffffffffffffffff, 0x0, 0x0, 0x200007fd, &(0x7f0000e68000)={0x2, 0x4e23, @local}, 0x10) program did not crash testing program (duration=7m58.835192883s, {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}}): socket$nl_netfilter-socket$inet-sendto$inet detailed listing: executing program 0: socket$nl_netfilter(0x10, 0x3, 0xc) r0 = socket$inet(0x2, 0x4000000000000001, 0x0) sendto$inet(r0, 0x0, 0x0, 0x200007fd, &(0x7f0000e68000)={0x2, 0x4e23, @local}, 0x10) program did not crash testing program (duration=7m58.835192883s, {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}}): sendmsg$NFT_BATCH-socket$inet-sendto$inet detailed listing: executing program 0: sendmsg$NFT_BATCH(0xffffffffffffffff, &(0x7f0000000080)={0x0, 0x0, &(0x7f0000000040)={&(0x7f0000000600)=ANY=[@ANYBLOB="140000001000010000000000000000000000000a20000000000a010300000000000000000100fffd0900010073797a300000000040000000030a01020000000000000000010000000900030073797a3200000000140004800800024032658aeb08000140000000010900010073797a300000000044000000060a010400000000000001040100000008000b40000000000900010073797a30000000001c000480180001800d00010073796e70726f7879000000000400028014000000110001"], 0xcc}, 0x1, 0x0, 0x0, 0x40000}, 0x0) r0 = socket$inet(0x2, 0x4000000000000001, 0x0) sendto$inet(r0, 0x0, 0x0, 0x200007fd, &(0x7f0000e68000)={0x2, 0x4e23, @local}, 0x10) program did not crash testing program (duration=7m58.835192883s, {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}}): socket$nl_netfilter-sendmsg$NFT_BATCH-socket$inet-sendto$inet detailed listing: executing program 0: r0 = socket$nl_netfilter(0x10, 0x3, 0xc) sendmsg$NFT_BATCH(r0, 0x0, 0x0) r1 = socket$inet(0x2, 0x4000000000000001, 0x0) sendto$inet(r1, 0x0, 0x0, 0x200007fd, &(0x7f0000e68000)={0x2, 0x4e23, @local}, 0x10) program did not crash testing program (duration=7m58.835192883s, {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}}): socket$nl_netfilter-sendmsg$NFT_BATCH-socket$inet-sendto$inet detailed listing: executing program 0: r0 = socket$nl_netfilter(0x10, 0x3, 0xc) sendmsg$NFT_BATCH(r0, &(0x7f0000000080)={0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x40000}, 0x0) r1 = socket$inet(0x2, 0x4000000000000001, 0x0) sendto$inet(r1, 0x0, 0x0, 0x200007fd, &(0x7f0000e68000)={0x2, 0x4e23, @local}, 0x10) program did not crash testing program (duration=7m58.835192883s, {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}}): socket$nl_netfilter-sendmsg$NFT_BATCH-socket$inet-sendto$inet detailed listing: executing program 0: r0 = socket$nl_netfilter(0x10, 0x3, 0xc) sendmsg$NFT_BATCH(r0, &(0x7f0000000080)={0x0, 0x0, &(0x7f0000000040)={0x0, 0xcc}, 0x1, 0x0, 0x0, 0x40000}, 0x0) r1 = socket$inet(0x2, 0x4000000000000001, 0x0) sendto$inet(r1, 0x0, 0x0, 0x200007fd, &(0x7f0000e68000)={0x2, 0x4e23, @local}, 0x10) program did not crash testing program (duration=7m58.835192883s, {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}}): socket$nl_netfilter-sendmsg$NFT_BATCH-socket$inet-sendto$inet detailed listing: executing program 0: r0 = socket$nl_netfilter(0x10, 0x3, 0xc) sendmsg$NFT_BATCH(r0, &(0x7f0000000080)={0x0, 0x0, &(0x7f0000000040)={&(0x7f0000000600)=ANY=[@ANYBLOB], 0xcc}, 0x1, 0x0, 0x0, 0x40000}, 0x0) r1 = socket$inet(0x2, 0x4000000000000001, 0x0) sendto$inet(r1, 0x0, 0x0, 0x200007fd, &(0x7f0000e68000)={0x2, 0x4e23, @local}, 0x10) program did not crash testing program (duration=7m58.835192883s, {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}}): socket$nl_netfilter-sendmsg$NFT_BATCH-socket$inet-sendto$inet detailed listing: executing program 0: r0 = socket$nl_netfilter(0x10, 0x3, 0xc) sendmsg$NFT_BATCH(r0, &(0x7f0000000080)={0x0, 0x0, &(0x7f0000000040)={&(0x7f0000000600)=ANY=[@ANYBLOB="140000001000010000000000000000000000000a20000000000a010300000000000000000100fffd0900010073797a300000000040000000030a01020000000000000000010000000900030073797a3200000000140004800800024032658aeb08000140000000010900010073797a300000000044000000060a010400000000000001040100000008000b40000000000900010073797a30000000001c000480180001800d00010073796e70726f7879000000000400028014000000110001"], 0xcc}, 0x1, 0x0, 0x0, 0x40000}, 0x0) r1 = socket$inet(0x2, 0x4000000000000001, 0x0) sendto$inet(r1, 0x0, 0x0, 0x200007fd, 0x0, 0x0) program did not crash extracting C reproducer testing compiled C program (duration=7m58.835192883s, {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}}): socket$nl_netfilter-sendmsg$NFT_BATCH-socket$inet-sendto$inet program crashed: INFO: task hung in cfg80211_event_work a never seen crash title: INFO: task hung in cfg80211_event_work, ignore simplifying guilty program options testing program (duration=7m58.835192883s, {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}}): socket$nl_netfilter-sendmsg$NFT_BATCH-socket$inet-sendto$inet detailed listing: executing program 0: r0 = socket$nl_netfilter(0x10, 0x3, 0xc) sendmsg$NFT_BATCH(r0, &(0x7f0000000080)={0x0, 0x0, &(0x7f0000000040)={&(0x7f0000000600)=ANY=[@ANYBLOB="140000001000010000000000000000000000000a20000000000a010300000000000000000100fffd0900010073797a300000000040000000030a01020000000000000000010000000900030073797a3200000000140004800800024032658aeb08000140000000010900010073797a300000000044000000060a010400000000000001040100000008000b40000000000900010073797a30000000001c000480180001800d00010073796e70726f7879000000000400028014000000110001"], 0xcc}, 0x1, 0x0, 0x0, 0x40000}, 0x0) r1 = socket$inet(0x2, 0x4000000000000001, 0x0) sendto$inet(r1, 0x0, 0x0, 0x200007fd, &(0x7f0000e68000)={0x2, 0x4e23, @local}, 0x10) program crashed: INFO: task hung in inet6_rtm_newaddr a never seen crash title: INFO: task hung in inet6_rtm_newaddr, ignore testing program (duration=7m58.835192883s, {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}}): socket$nl_netfilter-sendmsg$NFT_BATCH-socket$inet-sendto$inet detailed listing: executing program 0: r0 = socket$nl_netfilter(0x10, 0x3, 0xc) sendmsg$NFT_BATCH(r0, &(0x7f0000000080)={0x0, 0x0, &(0x7f0000000040)={&(0x7f0000000600)=ANY=[@ANYBLOB="140000001000010000000000000000000000000a20000000000a010300000000000000000100fffd0900010073797a300000000040000000030a01020000000000000000010000000900030073797a3200000000140004800800024032658aeb08000140000000010900010073797a300000000044000000060a010400000000000001040100000008000b40000000000900010073797a30000000001c000480180001800d00010073796e70726f7879000000000400028014000000110001"], 0xcc}, 0x1, 0x0, 0x0, 0x40000}, 0x0) r1 = socket$inet(0x2, 0x4000000000000001, 0x0) sendto$inet(r1, 0x0, 0x0, 0x200007fd, &(0x7f0000e68000)={0x2, 0x4e23, @local}, 0x10) program crashed: INFO: task hung in inet_rtm_newaddr a never seen crash title: INFO: task hung in inet_rtm_newaddr, ignore testing program (duration=7m58.835192883s, {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}}): socket$nl_netfilter-sendmsg$NFT_BATCH-socket$inet-sendto$inet detailed listing: executing program 0: r0 = socket$nl_netfilter(0x10, 0x3, 0xc) sendmsg$NFT_BATCH(r0, &(0x7f0000000080)={0x0, 0x0, &(0x7f0000000040)={&(0x7f0000000600)=ANY=[@ANYBLOB="140000001000010000000000000000000000000a20000000000a010300000000000000000100fffd0900010073797a300000000040000000030a01020000000000000000010000000900030073797a3200000000140004800800024032658aeb08000140000000010900010073797a300000000044000000060a010400000000000001040100000008000b40000000000900010073797a30000000001c000480180001800d00010073796e70726f7879000000000400028014000000110001"], 0xcc}, 0x1, 0x0, 0x0, 0x40000}, 0x0) r1 = socket$inet(0x2, 0x4000000000000001, 0x0) sendto$inet(r1, 0x0, 0x0, 0x200007fd, &(0x7f0000e68000)={0x2, 0x4e23, @local}, 0x10) program crashed: INFO: task hung in tun_chr_close validation run: crashed=true testing program (duration=7m58.835192883s, {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}}): socket$nl_netfilter-sendmsg$NFT_BATCH-socket$inet-sendto$inet detailed listing: executing program 0: r0 = socket$nl_netfilter(0x10, 0x3, 0xc) sendmsg$NFT_BATCH(r0, &(0x7f0000000080)={0x0, 0x0, &(0x7f0000000040)={&(0x7f0000000600)=ANY=[@ANYBLOB="140000001000010000000000000000000000000a20000000000a010300000000000000000100fffd0900010073797a300000000040000000030a01020000000000000000010000000900030073797a3200000000140004800800024032658aeb08000140000000010900010073797a300000000044000000060a010400000000000001040100000008000b40000000000900010073797a30000000001c000480180001800d00010073796e70726f7879000000000400028014000000110001"], 0xcc}, 0x1, 0x0, 0x0, 0x40000}, 0x0) r1 = socket$inet(0x2, 0x4000000000000001, 0x0) sendto$inet(r1, 0x0, 0x0, 0x200007fd, &(0x7f0000e68000)={0x2, 0x4e23, @local}, 0x10) program crashed: INFO: task hung in addrconf_dad_work validation run: crashed=true testing program (duration=7m58.835192883s, {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}}): socket$nl_netfilter-sendmsg$NFT_BATCH-socket$inet-sendto$inet detailed listing: executing program 0: r0 = socket$nl_netfilter(0x10, 0x3, 0xc) sendmsg$NFT_BATCH(r0, &(0x7f0000000080)={0x0, 0x0, &(0x7f0000000040)={&(0x7f0000000600)=ANY=[@ANYBLOB="140000001000010000000000000000000000000a20000000000a010300000000000000000100fffd0900010073797a300000000040000000030a01020000000000000000010000000900030073797a3200000000140004800800024032658aeb08000140000000010900010073797a300000000044000000060a010400000000000001040100000008000b40000000000900010073797a30000000001c000480180001800d00010073796e70726f7879000000000400028014000000110001"], 0xcc}, 0x1, 0x0, 0x0, 0x40000}, 0x0) r1 = socket$inet(0x2, 0x4000000000000001, 0x0) sendto$inet(r1, 0x0, 0x0, 0x200007fd, &(0x7f0000e68000)={0x2, 0x4e23, @local}, 0x10) program crashed: INFO: task hung in addrconf_dad_work validation run: crashed=true reproducing took 1h48m7.630821903s repro crashed as (corrupted=false): INFO: task kworker/u4:14:2955 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:14 state:D stack:25688 pid:2955 tgid:2955 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 rtnl_net_lock include/linux/rtnetlink.h:130 [inline] addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Showing all locks held in the system: 4 locks held by kworker/0:0/9: 2 locks held by kworker/0:1/10: 2 locks held by kworker/u4:0/12: 4 locks held by kworker/u4:1/13: 3 locks held by kworker/u4:2/25: 1 lock held by khungtaskd/27: #0: ffffffff8e1419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e1419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e1419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u4:3/43: 3 locks held by kworker/u4:4/69: 2 locks held by kworker/u4:5/760: 4 locks held by kworker/0:2/785: #0: ffff888043ebc948 ((wq_completion)wg-kex-wg1#4){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff888043ebc948 ((wq_completion)wg-kex-wg1#4){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc90001c57b80 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90001c57b80 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 final repro crashed as (corrupted=false): INFO: task kworker/u4:14:2955 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:14 state:D stack:25688 pid:2955 tgid:2955 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 rtnl_net_lock include/linux/rtnetlink.h:130 [inline] addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Showing all locks held in the system: 4 locks held by kworker/0:0/9: 2 locks held by kworker/0:1/10: 2 locks held by kworker/u4:0/12: 4 locks held by kworker/u4:1/13: 3 locks held by kworker/u4:2/25: 1 lock held by khungtaskd/27: #0: ffffffff8e1419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e1419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e1419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u4:3/43: 3 locks held by kworker/u4:4/69: 2 locks held by kworker/u4:5/760: 4 locks held by kworker/0:2/785: #0: ffff888043ebc948 ((wq_completion)wg-kex-wg1#4){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff888043ebc948 ((wq_completion)wg-kex-wg1#4){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc90001c57b80 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90001c57b80 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340