syzbot


BUG: soft lockup in x64_sys_call (2)

Status: fixed on 2026/03/04 11:24
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+bc0fb13d6683d84d012d@syzkaller.appspotmail.com
Fix commit: FROMGIT: rust_binder: call set_notification_done() without proc lock
First crash: 42d, last: 29d
Bug presence (2)
Date Name Commit Repro Result
2026/02/23 lts (merge base) ff2177382799 C Didn't crash
2026/02/23 upstream (ToT) 6de23f81a5e0 C [report] BUG: soft lockup in x64_sys_call
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 BUG: soft lockup in x64_sys_call origin:upstream 1 C 29 1d14h 577d 0/2 upstream: reported C repro on 2024/08/25 04:51
android-6-1 BUG: soft lockup in x64_sys_call origin:upstream 1 C error 7 24d 38d 0/2 upstream: reported C repro on 2026/02/15 08:06
android-6-12 BUG: soft lockup in x64_sys_call 1 23 140d 275d 0/1 auto-obsoleted due to no activity on 2026/01/28 18:33
linux-5.15 INFO: rcu detected stall in x64_sys_call 1 1 635d 635d 0/3 auto-obsoleted due to no activity on 2024/10/06 02:18
upstream INFO: rcu detected stall in x64_sys_call mm 1 C error 513 1d18h 562d 0/29 upstream: reported C repro on 2024/09/09 20:48
linux-6.1 INFO: rcu detected stall in x64_sys_call 1 1 326d 326d 0/3 auto-obsoleted due to no activity on 2025/08/11 06:03
Last patch testing requests (2)
Created Duration User Patch Repo Result
2026/03/03 20:23 16m aliceryhl@google.com android16-6.12 OK log
2026/02/24 18:21 15m aliceryhl@google.com patch android16-6.12 OK log

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 144s! [syz.2.11424:31268]
CPU#0 Utilization every 22s during lockup:
	#1: 100% system,	  1% softirq,	  1% hardirq,	  0% idle
	#2: 100% system,	  1% softirq,	  1% hardirq,	  0% idle
	#3: 100% system,	  0% softirq,	  1% hardirq,	  0% idle
	#4: 100% system,	  0% softirq,	  1% hardirq,	  0% idle
	#5: 100% system,	  1% softirq,	  1% hardirq,	  0% idle
Modules linked in:
CPU: 0 UID: 0 PID: 31268 Comm: syz.2.11424 Not tainted syzkaller #0 955f6180463debd82b9f2b9d8786ee899826498b
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:106
Code: cc cc cc cc cc cc cc b8 0e e7 a0 f1 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d f3 9b 48 00 55 48 89 e5 fb f4 <5d> e9 07 60 02 00 cc cc cc cc cc cc cc b8 00 00 00 00 90 90 90 90
RSP: 0018:ffffc900056379d0 EFLAGS: 000002d3
RAX: ffffffff814428e1 RBX: 0000000000000001 RCX: ffff888113369300
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffffc900056379d0 R08: ffff8881f6e50a94 R09: 1ffff1103edca152
R10: dffffc0000000000 R11: ffffed103edca153 R12: dffffc0000000000
R13: 0000000000000200 R14: 0000000000000001 R15: 1ffff92000ac6f3c
FS:  000055558d257500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffb3f6700c CR3: 00000001252b6000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:112 [inline]
 kvm_wait+0x1c6/0x230 arch/x86/kernel/kvm.c:1081
 pv_wait arch/x86/include/asm/paravirt.h:596 [inline]
 pv_wait_node kernel/locking/qspinlock_paravirt.h:322 [inline]
 __pv_queued_spin_lock_slowpath+0x483/0xe90 kernel/locking/qspinlock.c:473
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock include/linux/spinlock.h:187 [inline]
 __raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline]
 _raw_spin_lock+0x115/0x120 kernel/locking/spinlock.c:154
 <kernel::sync::lock::Lock<rust_binder_main::process::ProcessInner, kernel::sync::lock::spinlock::SpinLockBackend>>::lock rust/kernel/sync/lock.rs:142 [inline]
 <rust_binder_main::process::Process>::flush drivers/android/binder/process.rs:1649 [inline]
 rust_binder_main::rust_binder_flush+0xff/0x3b0 drivers/android/binder/rust_binder_main.rs:497
 filp_flush fs/open.c:1552 [inline]
 filp_close+0xc0/0x160 fs/open.c:1565
 __range_close fs/file.c:710 [inline]
 __close_range+0x529/0x6e0 fs/file.c:767
 __do_sys_close_range fs/open.c:1618 [inline]
 __se_sys_close_range fs/open.c:1615 [inline]
 __x64_sys_close_range+0x7e/0x90 fs/open.c:1615
 x64_sys_call+0x1686/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:437
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f5497f9c629
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe3cd72e98 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007f5498217da0 RCX: 00007f5497f9c629
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f5498217da0 R08: 0000000000000006 R09: 0000000000000000
R10: 00007f5498217cb0 R11: 0000000000000246 R12: 000000000006b884
R13: 00007f5498215fac R14: 000000000006b577 R15: 00007ffe3cd72fa0
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31269 Comm: syz.2.11424 Not tainted syzkaller #0 955f6180463debd82b9f2b9d8786ee899826498b
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:106
Code: cc cc cc cc cc cc cc b8 0e e7 a0 f1 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d f3 9b 48 00 55 48 89 e5 fb f4 <5d> e9 07 60 02 00 cc cc cc cc cc cc cc b8 00 00 00 00 90 90 90 90
RSP: 0018:ffffc900056241b0 EFLAGS: 000002d3
RAX: ffffffff814428e1 RBX: 0000000000000003 RCX: ffff88811deeb900
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000003
RBP: ffffc900056241b0 R08: ffff888119bb8088 R09: 1ffff11023377011
R10: dffffc0000000000 R11: ffffed1023377012 R12: dffffc0000000000
R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff92000ac4838
FS:  00007f5498ef76c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5498ed5ff8 CR3: 00000001252b6000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:112 [inline]
 kvm_wait+0x1c6/0x230 arch/x86/kernel/kvm.c:1081
 pv_wait arch/x86/include/asm/paravirt.h:596 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:466 [inline]
 __pv_queued_spin_lock_slowpath+0x8e0/0xe90 kernel/locking/qspinlock.c:508
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock include/linux/spinlock.h:187 [inline]
 __raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline]
 _raw_spin_lock+0x115/0x120 kernel/locking/spinlock.c:154
 <kernel::sync::lock::Lock<rust_binder_main::process::ProcessInner, kernel::sync::lock::spinlock::SpinLockBackend>>::lock rust/kernel/sync/lock.rs:142 [inline]
 <rust_binder_main::process::Process>::push_work drivers/android/binder/process.rs:730 [inline]
 <rust_binder_main::thread::Thread>::push_work_if_looper+0x202/0x620 drivers/android/binder/thread.rs:667
 <rust_binder_main::node::NodeDeath>::set_notification_done drivers/android/binder/node.rs:1044 [inline]
 <rust_binder_main::process::Process>::dead_binder_done drivers/android/binder/process.rs:1312 [inline]
 <rust_binder_main::thread::Thread>::write+0x3aa3/0xa690 drivers/android/binder/thread.rs:1505
 <rust_binder_main::thread::Thread>::write_read drivers/android/binder/thread.rs:1608 [inline]
 <rust_binder_main::process::Process>::ioctl_write_read drivers/android/binder/process.rs:1609 [inline]
 <rust_binder_main::process::Process>::ioctl drivers/android/binder/process.rs:1674 [inline]
 rust_binder_main::rust_binder_ioctl+0x1077/0x5da0 drivers/android/binder/rust_binder_main.rs:449
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0x135/0x1b0 fs/ioctl.c:893
 __x64_sys_ioctl+0x7f/0xa0 fs/ioctl.c:893
 x64_sys_call+0x1878/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f5497f9c629
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5498ef7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f5498215fa0 RCX: 00007f5497f9c629
RDX: 0000200000000040 RSI: 00000000c0306201 RDI: 0000000000000003
RBP: 00007f5498032b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5498216038 R14: 00007f5498215fa0 R15: 00007ffe3cd72d38
 </TASK>

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/23 01:15 android16-6.12 c190014704c7 6e7b5511 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust BUG: soft lockup in x64_sys_call
2026/02/22 23:57 android16-6.12 c190014704c7 6e7b5511 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust BUG: soft lockup in x64_sys_call
2026/02/22 20:56 android16-6.12 c190014704c7 6e7b5511 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust BUG: soft lockup in x64_sys_call
2026/02/24 07:54 android16-6.12 569fa7be00d7 41d2fa6a .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust BUG: soft lockup in x64_sys_call
2026/02/11 14:12 android16-6.12 2f977140595b 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust BUG: soft lockup in x64_sys_call
2026/02/11 01:59 android16-6.12 c9f98ae7122b 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust BUG: soft lockup in x64_sys_call
* Struck through repros no longer work on HEAD.