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@xxxxxxxxxxxxxxxxxxxxxxxxx
------------[ 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@xxxxxxxxxxxxxxxx.
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
