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[PATCH] fs: f2fs: remove WARN_ON in f2fs_is_valid_blkaddr

Dongliang Mu posted 1 patch 4 years, 1 month ago
There is a newer version of this series
fs/f2fs/checkpoint.c | 2 --
1 file changed, 2 deletions(-)
[PATCH] fs: f2fs: remove WARN_ON in f2fs_is_valid_blkaddr
Posted by Dongliang Mu 4 years, 1 month ago 
From: Dongliang Mu <mudongliangabcd@gmail.com>

In f2fs_is_valid_blkaddr, if type is DATA_GENERIC_ENHANCE or
DATA_GENERIC_ENHANCE_READ, it invokes WARN_ON(1) not matter
blkaddr is in the range or not.

Fix this by removing WARN_ON.

Note that, syzbot patch testing does not incur any further issues

Reported-by: syzbot+763ae12a2ede1d99d4dc@syzkaller.appspotmail.com
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
---
 fs/f2fs/checkpoint.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index f5366feea82d..521498b2dd8c 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -158,7 +158,6 @@ static bool __is_bitmap_valid(struct f2fs_sb_info *sbi, block_t blkaddr,
 		f2fs_err(sbi, "Inconsistent error blkaddr:%u, sit bitmap:%d",
 			 blkaddr, exist);
 		set_sbi_flag(sbi, SBI_NEED_FSCK);
-		WARN_ON(1);
 	}
 	return exist;
 }
@@ -196,7 +195,6 @@ bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
 			f2fs_warn(sbi, "access invalid blkaddr:%u",
 				  blkaddr);
 			set_sbi_flag(sbi, SBI_NEED_FSCK);
-			WARN_ON(1);
 			return false;
 		} else {
 			return __is_bitmap_valid(sbi, blkaddr, type);
-- 
2.25.1
Re: [PATCH] fs: f2fs: remove WARN_ON in f2fs_is_valid_blkaddr
Posted by Chao Yu 4 years, 1 month ago 
On 2022/4/8 13:22, Dongliang Mu wrote:
> From: Dongliang Mu <mudongliangabcd@gmail.com>
> 
> In f2fs_is_valid_blkaddr, if type is DATA_GENERIC_ENHANCE or
> DATA_GENERIC_ENHANCE_READ, it invokes WARN_ON(1) not matter
> blkaddr is in the range or not.

If we run into the path where we invoke WARN_ON(1) in f2fs_is_valid_blkaddr(),
It means f2fs image may be broken, or there is a bug in f2fs.

So, do you suffer any related issue in your environment?

Thanks,

> 
> Fix this by removing WARN_ON.
> 
> Note that, syzbot patch testing does not incur any further issues
> 
> Reported-by: syzbot+763ae12a2ede1d99d4dc@syzkaller.appspotmail.com
> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> ---
>   fs/f2fs/checkpoint.c | 2 --
>   1 file changed, 2 deletions(-)
> 
> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> index f5366feea82d..521498b2dd8c 100644
> --- a/fs/f2fs/checkpoint.c
> +++ b/fs/f2fs/checkpoint.c
> @@ -158,7 +158,6 @@ static bool __is_bitmap_valid(struct f2fs_sb_info *sbi, block_t blkaddr,
>   		f2fs_err(sbi, "Inconsistent error blkaddr:%u, sit bitmap:%d",
>   			 blkaddr, exist);
>   		set_sbi_flag(sbi, SBI_NEED_FSCK);
> -		WARN_ON(1);
>   	}
>   	return exist;
>   }
> @@ -196,7 +195,6 @@ bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
>   			f2fs_warn(sbi, "access invalid blkaddr:%u",
>   				  blkaddr);
>   			set_sbi_flag(sbi, SBI_NEED_FSCK);
> -			WARN_ON(1);
>   			return false;
>   		} else {
>   			return __is_bitmap_valid(sbi, blkaddr, type);
Re: [PATCH] fs: f2fs: remove WARN_ON in f2fs_is_valid_blkaddr
Posted by Dongliang Mu 4 years, 1 month ago 
On Sat, Apr 9, 2022 at 8:27 AM Chao Yu <chao@kernel.org> wrote:
>
> On 2022/4/8 13:22, Dongliang Mu wrote:
> > From: Dongliang Mu <mudongliangabcd@gmail.com>
> >
> > In f2fs_is_valid_blkaddr, if type is DATA_GENERIC_ENHANCE or
> > DATA_GENERIC_ENHANCE_READ, it invokes WARN_ON(1) not matter
> > blkaddr is in the range or not.
>
> If we run into the path where we invoke WARN_ON(1) in f2fs_is_valid_blkaddr(),
> It means f2fs image may be broken, or there is a bug in f2fs.
>
> So, do you suffer any related issue in your environment?

related issue? Can you explain a little?

If you mean if this warning occurs, any other issues or crash
behaviors are generated? I tested on the syzbot. After removing the
WARN_ON, there is no abnormal issue or crash behaviors followed with
the corresponding reproducer.


>
> Thanks,
>
> >
> > Fix this by removing WARN_ON.
> >
> > Note that, syzbot patch testing does not incur any further issues
> >
> > Reported-by: syzbot+763ae12a2ede1d99d4dc@syzkaller.appspotmail.com
> > Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> > ---
> >   fs/f2fs/checkpoint.c | 2 --
> >   1 file changed, 2 deletions(-)
> >
> > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > index f5366feea82d..521498b2dd8c 100644
> > --- a/fs/f2fs/checkpoint.c
> > +++ b/fs/f2fs/checkpoint.c
> > @@ -158,7 +158,6 @@ static bool __is_bitmap_valid(struct f2fs_sb_info *sbi, block_t blkaddr,
> >               f2fs_err(sbi, "Inconsistent error blkaddr:%u, sit bitmap:%d",
> >                        blkaddr, exist);
> >               set_sbi_flag(sbi, SBI_NEED_FSCK);
> > -             WARN_ON(1);
> >       }
> >       return exist;
> >   }
> > @@ -196,7 +195,6 @@ bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
> >                       f2fs_warn(sbi, "access invalid blkaddr:%u",
> >                                 blkaddr);
> >                       set_sbi_flag(sbi, SBI_NEED_FSCK);
> > -                     WARN_ON(1);
> >                       return false;
> >               } else {
> >                       return __is_bitmap_valid(sbi, blkaddr, type);
Re: [PATCH] fs: f2fs: remove WARN_ON in f2fs_is_valid_blkaddr
Posted by Chao Yu 4 years, 1 month ago 
On 2022/4/9 9:34, Dongliang Mu wrote:
> On Sat, Apr 9, 2022 at 8:27 AM Chao Yu <chao@kernel.org> wrote:
>>
>> On 2022/4/8 13:22, Dongliang Mu wrote:
>>> From: Dongliang Mu <mudongliangabcd@gmail.com>
>>>
>>> In f2fs_is_valid_blkaddr, if type is DATA_GENERIC_ENHANCE or
>>> DATA_GENERIC_ENHANCE_READ, it invokes WARN_ON(1) not matter
>>> blkaddr is in the range or not.
>>
>> If we run into the path where we invoke WARN_ON(1) in f2fs_is_valid_blkaddr(),
>> It means f2fs image may be broken, or there is a bug in f2fs.
>>
>> So, do you suffer any related issue in your environment?
> 
> related issue? Can you explain a little?
> 
> If you mean if this warning occurs, any other issues or crash

I mean have you seen any warning info printed in the path of
f2fs_is_valid_blkaddr() before applying this patch, and if so, w/ what
reproducer? or you just figure out this patch from perspective of code
review?

Thanks,

> behaviors are generated? I tested on the syzbot. After removing the
> WARN_ON, there is no abnormal issue or crash behaviors followed with
> the corresponding reproducer.
> 
> 
>>
>> Thanks,
>>
>>>
>>> Fix this by removing WARN_ON.
>>>
>>> Note that, syzbot patch testing does not incur any further issues
>>>
>>> Reported-by: syzbot+763ae12a2ede1d99d4dc@syzkaller.appspotmail.com
>>> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
>>> ---
>>>    fs/f2fs/checkpoint.c | 2 --
>>>    1 file changed, 2 deletions(-)
>>>
>>> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
>>> index f5366feea82d..521498b2dd8c 100644
>>> --- a/fs/f2fs/checkpoint.c
>>> +++ b/fs/f2fs/checkpoint.c
>>> @@ -158,7 +158,6 @@ static bool __is_bitmap_valid(struct f2fs_sb_info *sbi, block_t blkaddr,
>>>                f2fs_err(sbi, "Inconsistent error blkaddr:%u, sit bitmap:%d",
>>>                         blkaddr, exist);
>>>                set_sbi_flag(sbi, SBI_NEED_FSCK);
>>> -             WARN_ON(1);
>>>        }
>>>        return exist;
>>>    }
>>> @@ -196,7 +195,6 @@ bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
>>>                        f2fs_warn(sbi, "access invalid blkaddr:%u",
>>>                                  blkaddr);
>>>                        set_sbi_flag(sbi, SBI_NEED_FSCK);
>>> -                     WARN_ON(1);
>>>                        return false;
>>>                } else {
>>>                        return __is_bitmap_valid(sbi, blkaddr, type);
Re: [PATCH] fs: f2fs: remove WARN_ON in f2fs_is_valid_blkaddr
Posted by Dongliang Mu 4 years, 1 month ago 
On Sat, Apr 9, 2022 at 11:46 AM Chao Yu <chao@kernel.org> wrote:
>
> On 2022/4/9 9:34, Dongliang Mu wrote:
> > On Sat, Apr 9, 2022 at 8:27 AM Chao Yu <chao@kernel.org> wrote:
> >>
> >> On 2022/4/8 13:22, Dongliang Mu wrote:
> >>> From: Dongliang Mu <mudongliangabcd@gmail.com>
> >>>
> >>> In f2fs_is_valid_blkaddr, if type is DATA_GENERIC_ENHANCE or
> >>> DATA_GENERIC_ENHANCE_READ, it invokes WARN_ON(1) not matter
> >>> blkaddr is in the range or not.
> >>
> >> If we run into the path where we invoke WARN_ON(1) in f2fs_is_valid_blkaddr(),
> >> It means f2fs image may be broken, or there is a bug in f2fs.
> >>
> >> So, do you suffer any related issue in your environment?
> >
> > related issue? Can you explain a little?
> >
> > If you mean if this warning occurs, any other issues or crash
>
> I mean have you seen any warning info printed in the path of
> f2fs_is_valid_blkaddr() before applying this patch, and if so, w/ what
> reproducer? or you just figure out this patch from perspective of code
> review?

Yes, I have seen both warning information from Syzbot [1] and my local
syzkaller instance.

In f2fs_is_valid_blkaddr, if the following condition is satisfied,
i.e., blkaddr is not in the right range [2], it will directly invoke
one WARN_ON.

if (unlikely(blkaddr >= MAX_BLKADDR(sbi) ||
                 blkaddr < MAIN_BLKADDR(sbi))) {

This is the case on Syzbot.

Otherwise, it will jump into __is_bitmap_valid. And if the following
condition is satisfied [3], it will trigger another WARN_ON.

exist = f2fs_test_bit(offset, se->cur_valid_map);
if (!exist && type == DATA_GENERIC_ENHANCE) {

This appears in my local syzbot instance, but unfortunately it does
not get any reproducer.

[1] https://syzkaller.appspot.com/bug?extid=763ae12a2ede1d99d4dc
[2] https://elixir.bootlin.com/linux/latest/source/fs/f2fs/checkpoint.c#L187
[3] https://elixir.bootlin.com/linux/latest/source/fs/f2fs/checkpoint.c#L135


>
> Thanks,
>
> > behaviors are generated? I tested on the syzbot. After removing the
> > WARN_ON, there is no abnormal issue or crash behaviors followed with
> > the corresponding reproducer.
> >
> >
> >>
> >> Thanks,
> >>
> >>>
> >>> Fix this by removing WARN_ON.
> >>>
> >>> Note that, syzbot patch testing does not incur any further issues
> >>>
> >>> Reported-by: syzbot+763ae12a2ede1d99d4dc@syzkaller.appspotmail.com
> >>> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> >>> ---
> >>>    fs/f2fs/checkpoint.c | 2 --
> >>>    1 file changed, 2 deletions(-)
> >>>
> >>> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> >>> index f5366feea82d..521498b2dd8c 100644
> >>> --- a/fs/f2fs/checkpoint.c
> >>> +++ b/fs/f2fs/checkpoint.c
> >>> @@ -158,7 +158,6 @@ static bool __is_bitmap_valid(struct f2fs_sb_info *sbi, block_t blkaddr,
> >>>                f2fs_err(sbi, "Inconsistent error blkaddr:%u, sit bitmap:%d",
> >>>                         blkaddr, exist);
> >>>                set_sbi_flag(sbi, SBI_NEED_FSCK);
> >>> -             WARN_ON(1);
> >>>        }
> >>>        return exist;
> >>>    }
> >>> @@ -196,7 +195,6 @@ bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
> >>>                        f2fs_warn(sbi, "access invalid blkaddr:%u",
> >>>                                  blkaddr);
> >>>                        set_sbi_flag(sbi, SBI_NEED_FSCK);
> >>> -                     WARN_ON(1);
> >>>                        return false;
> >>>                } else {
> >>>                        return __is_bitmap_valid(sbi, blkaddr, type);

Patchew 2.1-devel-ea86937

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