syzbot has found a reproducer for the following issue on: HEAD commit: 931e46dcbc7e Add linux-next specific files for 20250814 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=13d65af0580000 kernel config: https://syzkaller.appspot.com/x/.config?x=bb7fbecfa2364d1c dashboard link: https://syzkaller.appspot.com/bug?extid=97bc0b256218ed6df337 compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=142793a2580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17fcbdbc580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/68e3ffeee4c1/disk-931e46dc.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/3cc40de4a0c3/vmlinux-931e46dc.xz kernel image: https://storage.googleapis.com/syzbot-assets/aed3e4f6a518/bzImage-931e46dc.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+97bc0b256218ed6df337@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz-executor297:5890 blocked for more than 143 seconds. Not tainted 6.17.0-rc1-next-20250814-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor297 state:D stack:28168 pid:5890 tgid:5890 ppid:5887 task_flags:0x400040 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1360 kernel/locking/mutex.c:760 sync_bdevs+0x1ac/0x340 block/bdev.c:1288 ksys_sync+0xb9/0x150 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd97a9d2959 RSP: 002b:00007ffd0221b4d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd97a9d2959 RDX: 00007fd97a9d1b90 RSI: 0000000000000012 RDI: 00007fd97aa1b03b RBP: 000000000002219f R08: 0000000000000000 R09: 0000000000000006 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd0221b4ec R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001 </TASK> INFO: lockdep is turned off. NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.17.0-rc1-next-20250814-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.17.0-rc1-next-20250814-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 53 e8 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 1a 25 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8e207d80 EFLAGS: 000002c6 RAX: 302944256c608e00 RBX: ffffffff8196d368 RCX: 302944256c608e00 RDX: 0000000000000001 RSI: ffffffff8c04d960 RDI: ffffffff8196d368 RBP: ffffffff8e207eb8 R08: ffff8880b8632f9b R09: 1ffff110170c65f3 R10: dffffc0000000000 R11: ffffed10170c65f4 R12: ffffffff8fe4db30 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1c52a40 FS: 0000000000000000(0000) GS:ffff8881257d6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005595b06bc168 CR3: 000000000e336000 CR4: 00000000003526f0 Call Trace: <TASK> arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:756 start_kernel+0x3a9/0x410 init/main.c:1109 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147 </TASK> --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.
