syzbot

INFO: task syz.2.17:371 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.17        state:D stack:0     pid:371   tgid:371   ppid:367    flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6016 [inline]
 __schedule+0x1399/0x1fa0 kernel/sched/core.c:7870
 __schedule_loop kernel/sched/core.c:7951 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7966
 schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common+0x369/0x650 kernel/sched/completion.c:127
 wait_for_completion_state+0x19/0x40 kernel/sched/completion.c:264
 coredump_wait fs/coredump.c:448 [inline]
 do_coredump+0x8ad/0x2fe0 fs/coredump.c:629
 get_signal+0x11f8/0x14e0 kernel/signal.c:2918
 arch_do_signal_or_restart+0xbc/0x760 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 irqentry_exit_to_user_mode+0x4d/0xb0 kernel/entry/common.c:231
 irqentry_exit+0x16/0x60 kernel/entry/common.c:334
 exc_page_fault+0x65/0xc0 arch/x86/mm/fault.c:1537
 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f4e962527f7
RSP: 002b:00007ffe4d4930e0 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000000000000b RCX: 0000000000022e98
RDX: 00007ffe4d493100 RSI: 00007ffe4d493230 RDI: 000000000000000b
RBP: 00007f4e96617da0 R08: 000000002a789ec5 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000000 R12: 000000000002346a
R13: 00007f4e9661609c R14: 0000000000023192 R15: 00007f4e96616090
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 1a36ed5f0b44f46e7eaed3953ba11d0fea6dce7e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
 dump_stack+0x19/0x20 lib/dump_stack.c:129
 nmi_cpu_backtrace+0x2ba/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
 watchdog+0xdad/0xf00 kernel/hung_task.c:423
 kthread+0x2c6/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 1a36ed5f0b44f46e7eaed3953ba11d0fea6dce7e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:106
Code: cc cc cc cc cc cc cc b8 be 04 56 f9 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 53 eb 45 00 55 48 89 e5 fb f4 <5d> c3 cc cc cc cc cc cc cc cc cc cc cc b8 00 00 00 00 90 90 90 90
RSP: 0018:ffffc900001a7e00 EFLAGS: 000002c6
RAX: ffff8881f6f00000 RBX: ffff88810366cc00 RCX: ffffffff85a16bcd
RDX: 0000000000000001 RSI: 0000000000000004 RDI: 000000000002e22c
RBP: ffffc900001a7e00 R08: ffff8881f6f39773 R09: 1ffff1103ede72ee
R10: dffffc0000000000 R11: ffffed103ede72ef R12: 1ffff110206cd980
R13: 0000000000000001 R14: 0000000000000000 R15: ffffffff87ec1ca8
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d94b763018 CR3: 000000010c3ac000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:112 [inline]
 default_idle+0x17/0x30 arch/x86/kernel/process.c:754
 arch_cpu_idle+0xd/0x20 arch/x86/kernel/process.c:791
 default_idle_call+0x3e/0x80 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x19f/0x4b0 kernel/sched/idle.c:326
 cpu_startup_entry+0x47/0x60 kernel/sched/idle.c:424
 start_secondary+0x12e/0x140 arch/x86/kernel/smpboot.c:314
 common_startup_64+0x13b/0x157
 </TASK>