Re: [syzbot] riscv/fixes test error: can't ssh into the instance (2)

[Alexandre Ghiti <alex@ghiti.fr>]

On 5/19/25 12:12, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    01534f3e0dd7 Merge tag 'riscv-fixes-6.15-rc6' of ssh://git..
> git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes
> console output: https://syzkaller.appspot.com/x/log.txt?x=158796f4580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=2c32351e59d854b7
> dashboard link: https://syzkaller.appspot.com/bug?extid=2cae92ded758083f5bde
> compiler:       riscv64-linux-gnu-gcc (Debian 12.2.0-13) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> userspace arch: riscv64
>
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/a741b348759c/non_bootable_disk-01534f3e.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/4ca1cbb891a9/vmlinux-01534f3e.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/5fb1db315d47/Image-01534f3e.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+2cae92ded758083f5bde@syzkaller.appspotmail.com
>
>
>
> ---
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So we hit the following warning:

[   33.466472][    C6] WARNING: CPU: 6 PID: 1 at fs/sysfs/group.c:131 
internal_create_group+0xa22/0xdd8
[   33.471115][    C6] Modules linked in:
[   33.475123][    C6] CPU: 6 UID: 0 PID: 1 Comm: swapper/0 Not tainted 
6.15.0-rc6-dirty #3 PREEMPT
[   33.476075][    C6] Hardware name: riscv-virtio,qemu (DT)
[   33.476615][    C6] epc : internal_create_group+0xa22/0xdd8
[   33.477194][    C6]  ra : internal_create_group+0xa22/0xdd8
[   33.477696][    C6] epc : ffffffff80dd956c ra : ffffffff80dd956c sp : 
ffffffc600087b50
[   33.478048][    C6]  gp : ffffffff89a659e0 tp : ffffffd681688000 t0 : 
ffffffc600087a80
[   33.478377][    C6]  t1 : 1ffffff8c0010f78 t2 : ffffffff89b70a80 s0 : 
ffffffc600087cc0
[   33.478690][    C6]  s1 : ffffffc600087c40 a0 : 0000000000000000 a1 : 
0000000000000000
[   33.478990][    C6]  a2 : 0000000000000002 a3 : ffffffff80dd956c a4 : 
0000000000000000
[   33.479291][    C6]  a5 : ffffffd681689000 a6 : fffffffff1f1f1f1 a7 : 
ffffffff80dd8b4a
[   33.479602][    C6]  s2 : dfffffff00000000 s3 : ffffffff86a381a0 s4 : 
ffffffc600087dc0
[   33.479967][    C6]  s5 : 0000000000000002 s6 : 0000000000000000 s7 : 
0000000000000000
[   33.480327][    C6]  s8 : 1ffffffff136df40 s9 : ffffffff89b6fa00 s10: 
1ffffff8c0010fa4
[   33.480673][    C6]  s11: ffffffff87bece20 t3 : 0000000000000000 t4 : 
fffffffef10e33b2
[   33.481019][    C6]  t5 : fffffffef10e33b3 t6 : ffffffd68aabf2f8
[   33.481326][    C6] status: 0000000200000120 badaddr: 
ffffffff80dd956c cause: 0000000000000003
[   33.481962][    C6] [<ffffffff80dd956c>] 
internal_create_group+0xa22/0xdd8
[   33.482681][    C6] [<ffffffff80dd9944>] sysfs_create_group+0x22/0x2e
[   33.483136][    C6] [<ffffffff86289d82>] platform_profile_init+0x74/0xb2
[   33.483555][    C6] [<ffffffff80061860>] do_one_initcall+0x198/0xa9e
[   33.484158][    C6] [<ffffffff8620293e>] kernel_init_freeable+0x6d8/0x780
[   33.484689][    C6] [<ffffffff8609fe54>] kernel_init+0x28/0x24c
[   33.485208][    C6] [<ffffffff860c2542>] ret_from_fork+0xe/0x18
[   33.485885][    C6] irq event stamp: 950699
[   33.486072][    C6] hardirqs last  enabled at (950699): 
[<ffffffff80a6182c>] kasan_quarantine_put+0x1a8/0x208
[   33.486710][    C6] hardirqs last disabled at (950698): 
[<ffffffff80a61726>] kasan_quarantine_put+0xa2/0x208
[   33.487398][    C6] softirqs last  enabled at (950420): 
[<ffffffff801533a6>] handle_softirqs+0x98e/0x119c
[   33.487930][    C6] softirqs last disabled at (950413): 
[<ffffffff80153fd6>] __irq_exit_rcu+0x2e8/0x53c

Because we don't have acpi enabled and then acpi_kobj is null 
(https://elixir.bootlin.com/linux/v6.15-rc6/source/fs/sysfs/group.c#L131).

The following patch fixes it, but not sure this is the right way, let me 
know if I should send it, it would be nice to have it in 6.15:

diff --git a/drivers/acpi/platform_profile.c 
b/drivers/acpi/platform_profile.c
index ffbfd32f4cf1b..afbe4705d3e7a 100644
--- a/drivers/acpi/platform_profile.c
+++ b/drivers/acpi/platform_profile.c
@@ -688,6 +688,9 @@ static int __init platform_profile_init(void)
  {
         int err;

+       if (acpi_disabled)
+               return -ENOTSUPP;
+
         err = class_register(&platform_profile_class);
         if (err)
                 return err;

Thanks,

Alex