syzbot


INFO: task hung in rtnl_dumpit

Status: auto-obsoleted due to no activity on 2025/12/03 19:43
Reported-by: syzbot+3501c748b077f950ba72@syzkaller.appspotmail.com
First crash: 150d, last: 95d

Sample crash report:
INFO: task dhcpcd:148 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd          state:D stack:0     pid:148   tgid:148   ppid:147    flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5945 [inline]
 __schedule+0x1322/0x1df0 kernel/sched/core.c:7791
 __schedule_loop kernel/sched/core.c:7872 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7887
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
 rtnl_lock net/core/rtnetlink.c:79 [inline]
 rtnl_dumpit+0xa1/0x240 net/core/rtnetlink.c:6537
 netlink_dump+0x668/0xe40 net/netlink/af_netlink.c:2330
 __netlink_dump_start+0x6f8/0x980 net/netlink/af_netlink.c:2445
 netlink_dump_start include/linux/netlink.h:339 [inline]
 rtnetlink_dump_start net/core/rtnetlink.c:6567 [inline]
 rtnetlink_rcv_msg+0x717/0xa00 net/core/rtnetlink.c:6634
 netlink_rcv_skb+0x22e/0x4a0 net/netlink/af_netlink.c:2555
 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6696
 netlink_unicast_kernel net/netlink/af_netlink.c:1323 [inline]
 netlink_unicast+0x8c3/0xa60 net/netlink/af_netlink.c:1349
 netlink_sendmsg+0x7f0/0xaf0 net/netlink/af_netlink.c:1899
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x66d/0x6f0 net/socket.c:2217
 __do_sys_sendto net/socket.c:2229 [inline]
 __se_sys_sendto net/socket.c:2225 [inline]
 __x64_sys_sendto+0xe9/0x100 net/socket.c:2225
 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fed71fbf407
RSP: 002b:00007ffe35dfbcb0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fed71f35740 RCX: 00007fed71fbf407
RDX: 0000000000000014 RSI: 00007ffe35dfbd40 RDI: 0000000000000016
RBP: 00007ffe35dfbd24 R08: 00007ffe35dfbd24 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe35e1c630
R13: 00007fed71f356c8 R14: 00007ffe35dfbe20 R15: 00007ffe35e0c400
 </TASK>
INFO: task syz-executor:10277 blocked for more than 125 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:10277 tgid:10277 ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5945 [inline]
 __schedule+0x1322/0x1df0 kernel/sched/core.c:7791
 __schedule_loop kernel/sched/core.c:7872 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7887
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
 fib_net_exit_batch+0x24/0xa0 net/ipv4/fib_frontend.c:1652
 ops_exit_list net/core/net_namespace.c:178 [inline]
 setup_net+0x6f3/0x990 net/core/net_namespace.c:388
 copy_net_ns+0x513/0xa30 net/core/net_namespace.c:510
 create_new_namespaces+0x3b5/0x720 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x126/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x4fe/0x880 kernel/fork.c:3352
 __do_sys_unshare kernel/fork.c:3423 [inline]
 __se_sys_unshare kernel/fork.c:3421 [inline]
 __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3421
 x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f3df9d903e7
RSP: 002b:00007ffc5fd2fc38 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f3df9fc5f40 RCX: 00007f3df9d903e7
RDX: 0000000000000005 RSI: 00007ffc5fd2fb00 RDI: 0000000040000000
RBP: 00007f3df9fc67b8 R08: 00007f3dfaaf7d60 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:10278 blocked for more than 126 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:10278 tgid:10278 ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5945 [inline]
 __schedule+0x1322/0x1df0 kernel/sched/core.c:7791
 __schedule_loop kernel/sched/core.c:7872 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7887
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
 ip6mr_net_exit_batch+0x24/0xa0 net/ipv6/ip6mr.c:1374
 ops_exit_list net/core/net_namespace.c:178 [inline]
 setup_net+0x6f3/0x990 net/core/net_namespace.c:388
 copy_net_ns+0x513/0xa30 net/core/net_namespace.c:510
 create_new_namespaces+0x3b5/0x720 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x126/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x4fe/0x880 kernel/fork.c:3352
 __do_sys_unshare kernel/fork.c:3423 [inline]
 __se_sys_unshare kernel/fork.c:3421 [inline]
 __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3421
 x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fc7bcf903e7
RSP: 002b:00007ffcec845f88 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fc7bd1c5f40 RCX: 00007fc7bcf903e7
RDX: 0000000000000005 RSI: 00007ffcec845e50 RDI: 0000000040000000
RBP: 00007fc7bd1c67b8 R08: 00007fc7bdcf7d60 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:10281 blocked for more than 127 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:10281 tgid:10281 ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5945 [inline]
 __schedule+0x1322/0x1df0 kernel/sched/core.c:7791
 __schedule_loop kernel/sched/core.c:7872 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7887
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
 fib_net_exit_batch+0x24/0xa0 net/ipv4/fib_frontend.c:1652
 ops_exit_list net/core/net_namespace.c:178 [inline]
 setup_net+0x6f3/0x990 net/core/net_namespace.c:388
 copy_net_ns+0x513/0xa30 net/core/net_namespace.c:510
 create_new_namespaces+0x3b5/0x720 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x126/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x4fe/0x880 kernel/fork.c:3352
 __do_sys_unshare kernel/fork.c:3423 [inline]
 __se_sys_unshare kernel/fork.c:3421 [inline]
 __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3421
 x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f25819903e7
RSP: 002b:00007ffd09ef1b88 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f2581bc5f40 RCX: 00007f25819903e7
RDX: 0000000000000005 RSI: 00007ffd09ef1a50 RDI: 0000000040000000
RBP: 00007f2581bc67b8 R08: 00007f25826f7d60 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:10297 blocked for more than 128 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:10297 tgid:10297 ppid:1      flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5945 [inline]
 __schedule+0x1322/0x1df0 kernel/sched/core.c:7791
 __schedule_loop kernel/sched/core.c:7872 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7887
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
 rtnl_lock net/core/rtnetlink.c:79 [inline]
 rtnetlink_rcv_msg+0x75f/0xa00 net/core/rtnetlink.c:6675
 netlink_rcv_skb+0x22e/0x4a0 net/netlink/af_netlink.c:2555
 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6696
 netlink_unicast_kernel net/netlink/af_netlink.c:1323 [inline]
 netlink_unicast+0x8c3/0xa60 net/netlink/af_netlink.c:1349
 netlink_sendmsg+0x7f0/0xaf0 net/netlink/af_netlink.c:1899
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x66d/0x6f0 net/socket.c:2217
 __do_sys_sendto net/socket.c:2229 [inline]
 __se_sys_sendto net/socket.c:2225 [inline]
 __x64_sys_sendto+0xe9/0x100 net/socket.c:2225
 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f4b84790a23
RSP: 002b:00007ffeb8ec0f68 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f4b854f4620 RCX: 00007f4b84790a23
RDX: 000000000000002c RSI: 00007f4b854f4670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffeb8ec0f84 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f4b854f4670 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:10302 blocked for more than 129 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/04 19:41 android16-6.12 3a1f856821c2 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in rtnl_dumpit
2025/07/11 09:50 android16-6.12 5bbd30a60b96 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in rtnl_dumpit
* Struck through repros no longer work on HEAD.