syzbot


attempt to subtract with overflow in <kernel::task::Task>::rlimit_nice

Status: internal: reported C repro on 2025/10/21 21:52
Reported-by: syzbot+28662fd1366938044471@syzkaller.appspotmail.com
First crash: 37d, last: 37d
Bug presence (3)
Date Name Commit Repro Result
2025/11/23 android16-6.12 (ToT) c1902e025e9f C Failed due to an error; will retry later
2025/10/22 lts (merge base) b0c51e95f54e C Didn't crash
2025/10/22 upstream (ToT) 552c50713f27 C Didn't crash
Last patch testing requests (2)
Created Duration User Patch Repo Result
2025/11/07 23:01 3m retest repro android16-6.12 error
2025/11/07 23:01 3m retest repro android16-6.12 error

Sample crash report:
rust_kernel: panicked at rust/kernel/task.rs:316:9:
attempt to subtract with overflow
------------[ cut here ]------------
kernel BUG at rust/helpers/bug.c:7!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 UID: 0 PID: 381 Comm: syz.2.17 Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:rust_helper_BUG+0x8/0x10 rust/helpers/bug.c:7
Code: be 57 ee 02 cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 b8 57 97 9e bb 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 48 89 e5 <0f> 0b 66 0f 1f 44 00 00 b8 1d 53 d7 37 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000f4d090 EFLAGS: 00010246
RAX: 0000000000000055 RBX: 1ffff920001e9a14 RCX: df5a45821e9f2000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc90000f4d090 R08: ffffc90000f4cd87 R09: 1ffff920001e99b0
R10: dffffc0000000000 R11: fffff520001e99b1 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffc90000f4d0c0 R15: ffffc90000f4d0f0
FS:  00007f5c5c3eb6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5c5c3eaf98 CR3: 0000000115b3e000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 __rustc::rust_begin_unwind+0x15b/0x160 rust/kernel/lib.rs:130
 core::panicking::panic_fmt+0x84/0x90 usr/local/rustup/toolchains/1.87.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/panicking.rs:75
 core::panicking::panic_const::panic_const_sub_overflow+0xb2/0xc0 usr/local/rustup/toolchains/1.87.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/panicking.rs:178
 <kernel::task::Task>::rlimit_nice+0x54/0x70 rust/kernel/task.rs:316
 <rust_binder_main::thread::Thread>::do_set_priority+0x3f7/0xe10 drivers/android/binder/thread.rs:697
 <rust_binder_main::thread::Thread>::set_priority drivers/android/binder/thread.rs:751 [inline]
 <rust_binder_main::transaction::Transaction as rust_binder_main::DeliverToRead>::on_thread_selected+0x69d/0xae0 drivers/android/binder/transaction.rs:539
 <rust_binder_main::process::ProcessInner>::push_work+0x322/0xb30 drivers/android/binder/process.rs:178
 <rust_binder_main::transaction::Transaction>::submit+0x781/0x2040 drivers/android/binder/transaction.rs:337
 <rust_binder_main::thread::Thread>::transaction_inner drivers/android/binder/thread.rs:1335 [inline]
 <<rust_binder_main::thread::Thread>::transaction_inner as core::ops::function::FnOnce<(&kernel::sync::arc::Arc<rust_binder_main::thread::Thread>, &rust_binder_main::defs::BinderTransactionDataSg)>>::call_once usr/local/rustup/toolchains/1.87.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ops/function.rs:250 [inline]
 <rust_binder_main::thread::Thread>::transaction::<<rust_binder_main::thread::Thread>::transaction_inner>+0xb36/0xdd0 drivers/android/binder/thread.rs:1294
 <rust_binder_main::thread::Thread>::write drivers/android/binder/thread.rs:1425 [inline]
 <rust_binder_main::thread::Thread>::write_read+0x199c/0xa380 drivers/android/binder/thread.rs:1581
 <rust_binder_main::process::Process>::ioctl_write_read drivers/android/binder/process.rs:1576 [inline]
 <rust_binder_main::process::Process>::ioctl+0x40c/0x2cf0 drivers/android/binder/process.rs:1641
 rust_binder_main::rust_binder_unlocked_ioctl+0xa0/0x100 drivers/android/binder/rust_binder_main.rs:445
 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:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f5c5b58efc9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5c5c3eb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f5c5b7e6090 RCX: 00007f5c5b58efc9
RDX: 0000200000000180 RSI: 00000000c0306201 RDI: 0000000000000003
RBP: 00007f5c5b611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5c5b7e6128 R14: 00007f5c5b7e6090 R15: 00007fff1ab4ddb8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:rust_helper_BUG+0x8/0x10 rust/helpers/bug.c:7
Code: be 57 ee 02 cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 b8 57 97 9e bb 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 48 89 e5 <0f> 0b 66 0f 1f 44 00 00 b8 1d 53 d7 37 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000f4d090 EFLAGS: 00010246
RAX: 0000000000000055 RBX: 1ffff920001e9a14 RCX: df5a45821e9f2000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc90000f4d090 R08: ffffc90000f4cd87 R09: 1ffff920001e99b0
R10: dffffc0000000000 R11: fffff520001e99b1 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffc90000f4d0c0 R15: ffffc90000f4d0f0
FS:  00007f5c5c3eb6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5c5c3eaf98 CR3: 0000000115b3e000 CR4: 00000000003526b0

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/21 19:39 android16-6.12 0d6730ee6542 9832ed61 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust attempt to subtract with overflow in <kernel::task::Task>::rlimit_nice
2025/10/21 19:03 android16-6.12 0d6730ee6542 9832ed61 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust attempt to subtract with overflow in <kernel::task::Task>::rlimit_nice
2025/10/21 18:28 android16-6.12 0d6730ee6542 9832ed61 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust attempt to subtract with overflow in <kernel::task::Task>::rlimit_nice
2025/10/21 17:54 android16-6.12 0d6730ee6542 9832ed61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust attempt to subtract with overflow in <kernel::task::Task>::rlimit_nice
* Struck through repros no longer work on HEAD.