INFO: task hung in genl_rcv_msg

Status: auto-obsoleted due to no activity on 2026/03/07 22:43
Reported-by: syzbot+d46c0004fee0be3ef662@syzkaller.appspotmail.com
First crash: 257d, last: 257d
▶ ▼ Similar bugs (14)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in genl_rcv_msg (2) net 1 2 1130d 1164d 0/29 auto-obsoleted due to no activity on 2023/10/06 17:32
linux-5.15 INFO: task hung in genl_rcv_msg (3) 1 1 128d 128d 0/3 auto-obsoleted due to no activity on 2026/07/14 07:56
upstream INFO: task hung in genl_rcv_msg (3) net 1 syz, C done 13 861d 1003d 0/29 closed as invalid on 2024/04/16 10:15
upstream INFO: task hung in genl_rcv_msg (4) net 1 syz, C done 873 18h43m 678d 28/29 upstream: reported C repro on 2024/10/02 23:00
linux-6.1 INFO: task hung in genl_rcv_msg (2) 1 3 573d 687d 0/3 auto-obsoleted due to no activity on 2025/04/25 22:22
linux-5.15 INFO: task hung in genl_rcv_msg (2) 1 1 561d 561d 0/3 auto-obsoleted due to no activity on 2025/05/07 21:13
linux-4.19 INFO: task hung in genl_rcv_msg 1 syz error 17 1281d 2658d 0/1 upstream: reported syz repro on 2019/05/02 15:34
android-6-12 INFO: task hung in genl_rcv_msg 1 1 1d19h 1d19h 0/1 premoderation: reported on 2026/08/10 07:48
upstream INFO: task hung in genl_rcv_msg 1 syz done error 648 1310d 2857d 0/29 auto-obsoleted due to no activity on 2023/05/10 03:30
linux-4.14 INFO: task hung in genl_rcv_msg (2) 1 6 2093d 2281d 0/1 auto-closed as invalid on 2021/03/17 23:44
linux-6.1 INFO: task hung in genl_rcv_msg 1 1 968d 968d 0/3 auto-obsoleted due to no activity on 2024/03/26 09:02
linux-4.14 INFO: task hung in genl_rcv_msg 1 syz done 2 2398d 2398d 1/1 fixed on 2020/02/16 23:53
linux-6.1 INFO: task hung in genl_rcv_msg (3) 1 2 299d 318d 0/3 auto-obsoleted due to no activity on 2026/01/24 07:13
linux-5.15 INFO: task hung in genl_rcv_msg 1 1 1106d 1106d 0/3 auto-obsoleted due to no activity on 2023/11/09 20:26

Sample crash report:
INFO: task syz.2.60:6111 blocked for more than 156 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.60        state:D stack:24136 pid:6111  ppid:5831   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
 genl_lock net/netlink/genetlink.c:33 [inline]
 genl_op_lock net/netlink/genetlink.c:58 [inline]
 genl_rcv_msg+0x10e/0x790 net/netlink/genetlink.c:1065
 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1075
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
 ___sys_sendmsg+0x220/0x290 net/socket.c:2649
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2687 [inline]
 __se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc57758f749
RSP: 002b:00007fc5783a9038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc5777e5fa0 RCX: 00007fc57758f749
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000006
RBP: 00007fc577613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc5777e6038 R14: 00007fc5777e5fa0 R15: 00007fff8ce87da8
 </TASK>
INFO: task syz.1.62:6117 blocked for more than 166 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.62        state:D stack:26504 pid:6117  ppid:5829   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
 genl_lock net/netlink/genetlink.c:33 [inline]
 genl_op_lock net/netlink/genetlink.c:58 [inline]
 genl_rcv_msg+0x10e/0x790 net/netlink/genetlink.c:1065
 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1075
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/27 22:42 linux-6.6.y 1e89a1be4fe9 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in genl_rcv_msg
* Struck through repros no longer work on HEAD.