Messages in this thread | | | Date | Mon, 29 Apr 2024 10:45:47 -0700 | Subject | Re: [syzbot] [bpf?] [trace?] WARNING in group_send_sig_info | From | Yonghong Song <> |
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On 4/27/24 9:34 AM, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 443574b03387 riscv, bpf: Fix kfunc parameters incompatibil.. > git tree: bpf > console output: https://syzkaller.appspot.com/x/log.txt?x=11ca8fe7180000 > kernel config: https://syzkaller.appspot.com/x/.config?x=6fb1be60a193d440 > dashboard link: https://syzkaller.appspot.com/bug?extid=1902c6d326478ce2dfb0 > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/3f355021a085/disk-443574b0.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/44cf4de7472a/vmlinux-443574b0.xz > kernel image: https://storage.googleapis.com/syzbot-assets/a99a36c7ad65/bzImage-443574b0.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+1902c6d326478ce2dfb0@syzkaller.appspotmail.com > > ------------[ cut here ]------------ > raw_local_irq_restore() called with IRQs enabled > WARNING: CPU: 1 PID: 7785 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x29/0x40 kernel/locking/irqflag-debug.c:10 > Modules linked in: > CPU: 1 PID: 7785 Comm: syz-executor.3 Not tainted 6.8.0-syzkaller-05236-g443574b03387 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 > RIP: 0010:warn_bogus_irq_restore+0x29/0x40 kernel/locking/irqflag-debug.c:10 > Code: 90 f3 0f 1e fa 90 80 3d de 59 01 04 00 74 06 90 c3 cc cc cc cc c6 05 cf 59 01 04 01 90 48 c7 c7 20 ba aa 8b e8 f8 d5 e7 f5 90 <0f> 0b 90 90 90 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f > RSP: 0018:ffffc9000399fbb8 EFLAGS: 00010246 > > RAX: 4aede97b00455d00 RBX: 1ffff92000733f7c RCX: ffff88802a129e00 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: ffffc9000399fc50 R08: ffffffff8157cc12 R09: 1ffff110172a51a2 > R10: dffffc0000000000 R11: ffffed10172a51a3 R12: dffffc0000000000 > R13: 1ffff92000733f78 R14: ffffc9000399fbe0 R15: 0000000000000246 > FS: 000055557ae76480(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007ffc27e190f8 CR3: 000000006cb50000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] > _raw_spin_unlock_irqrestore+0x120/0x140 kernel/locking/spinlock.c:194 > spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] > unlock_task_sighand include/linux/sched/signal.h:754 [inline] > do_send_sig_info kernel/signal.c:1302 [inline] > group_send_sig_info+0x2e0/0x310 kernel/signal.c:1453 > bpf_send_signal_common+0x2dd/0x430 kernel/trace/bpf_trace.c:881 > ____bpf_send_signal kernel/trace/bpf_trace.c:886 [inline] > bpf_send_signal+0x19/0x30 kernel/trace/bpf_trace.c:884 > bpf_prog_8cc4ff36b5985b6a+0x1d/0x1f > bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] > __bpf_prog_run include/linux/filter.h:650 [inline] > bpf_prog_run include/linux/filter.h:664 [inline] > __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] > bpf_trace_run2+0x375/0x420 kernel/trace/bpf_trace.c:2420 > trace_sys_exit include/trace/events/syscalls.h:44 [inline] > syscall_exit_work+0x153/0x170 kernel/entry/common.c:163 > syscall_exit_to_user_mode_prepare kernel/entry/common.c:194 [inline] > __syscall_exit_to_user_mode_work kernel/entry/common.c:199 [inline] > syscall_exit_to_user_mode+0x273/0x360 kernel/entry/common.c:212 > do_syscall_64+0x10a/0x240 arch/x86/entry/common.c:89 > entry_SYSCALL_64_after_hwframe+0x6d/0x75
The following are related functions.
struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, unsigned long *flags) { struct sighand_struct *sighand;
rcu_read_lock(); for (;;) { sighand = rcu_dereference(tsk->sighand); if (unlikely(sighand == NULL)) break;
/* * This sighand can be already freed and even reused, but * we rely on SLAB_TYPESAFE_BY_RCU and sighand_ctor() which * initializes ->siglock: this slab can't go away, it has * the same object type, ->siglock can't be reinitialized. * * We need to ensure that tsk->sighand is still the same * after we take the lock, we can race with de_thread() or * __exit_signal(). In the latter case the next iteration * must see ->sighand == NULL. */ spin_lock_irqsave(&sighand->siglock, *flags); if (likely(sighand == rcu_access_pointer(tsk->sighand))) break; spin_unlock_irqrestore(&sighand->siglock, *flags); } rcu_read_unlock();
return sighand; }
static inline struct sighand_struct *lock_task_sighand(struct task_struct *task, unsigned long *flags) { struct sighand_struct *ret;
ret = __lock_task_sighand(task, flags); (void)__cond_lock(&task->sighand->siglock, ret); return ret; }
static inline void unlock_task_sighand(struct task_struct *task, unsigned long *flags) { spin_unlock_irqrestore(&task->sighand->siglock, *flags); }
int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p, enum pid_type type) { unsigned long flags; int ret = -ESRCH;
if (lock_task_sighand(p, &flags)) { ret = send_signal_locked(sig, info, p, type); unlock_task_sighand(p, &flags); } return ret; }
If p->sighand changed between lock_task_sighand() and unlock_task_sighand(), the warning makes sense. But I am not sure whether and how this could happen.
> RIP: 0033:0x7f8e47e7dc0b > Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 > RSP: 002b:00007ffd999e9950 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: fffffffffffffffa RBX: 0000000000000003 RCX: 00007f8e47e7dc0b > RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003 > RBP: 00007ffd999e9a0c R08: 0000000000000000 R09: 00007ffd999e96f7 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000032 > R13: 000000000004757a R14: 000000000004754c R15: 000000000000000f > </TASK> > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > If the report is already addressed, let syzbot know by replying with: > #syz fix: exact-commit-title > > If you want to overwrite report's subsystems, reply with: > #syz set subsystems: new-subsystem > (See the list of subsystem names on the web dashboard) > > If the report is a duplicate of another one, reply with: > #syz dup: exact-subject-of-another-report > > If you want to undo deduplication, reply with: > #syz undup >
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