Re: [f2fs-dev] [PATCH] f2fs: check memory boundary by insane namelen

2018-11-26 Thread Jaegeuk Kim 
On 11/23, Sheng Yong wrote:
> Hi, Jaegeuk and Chao,
> 
> On 2018/11/15 15:50, Jaegeuk Kim wrote:
> > If namelen is corrupted to have very long value, fill_dentries can copy
> > wrong memory area.
> > 
> Is there any scenario that could hit this corruption? Or this is triggered
> by fuzzing injection?

Hi Sheng,

It's from a fuzzing test.

Thanks,

> 
> thanks,
> Sheng Yong
> 
> > Signed-off-by: Jaegeuk Kim 
> > ---
> >   fs/f2fs/dir.c | 12 +++-
> >   1 file changed, 11 insertions(+), 1 deletion(-)
> > 
> > diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
> > index bacc667950b6..c0c845da12fa 100644
> > --- a/fs/f2fs/dir.c
> > +++ b/fs/f2fs/dir.c
> > @@ -808,6 +808,17 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct 
> > f2fs_dentry_ptr *d,
> > de_name.name = d->filename[bit_pos];
> > de_name.len = le16_to_cpu(de->name_len);
> > +   /* check memory boundary before moving forward */
> > +   bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
> > +   if (unlikely(bit_pos > d->max)) {
> > +   f2fs_msg(sbi->sb, KERN_WARNING,
> > +   "%s: corrupted namelen=%d, run fsck to fix.",
> > +   __func__, le16_to_cpu(de->name_len));
> > +   set_sbi_flag(sbi, SBI_NEED_FSCK);
> > +   err = -EINVAL;
> > +   goto out;
> > +   }
> > +
> > if (f2fs_encrypted_inode(d->inode)) {
> > int save_len = fstr->len;
> > @@ -830,7 +841,6 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct 
> > f2fs_dentry_ptr *d,
> > if (readdir_ra)
> > f2fs_ra_node_page(sbi, le32_to_cpu(de->ino));
> > -   bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
> > ctx->pos = start_pos + bit_pos;
> > }
> >   out:
> > 


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Re: [f2fs-dev] [PATCH] f2fs: check memory boundary by insane namelen

2018-11-24 Thread Chao Yu 
Hi Sheng,

On 2018/11/23 20:11, Sheng Yong wrote:
> Hi, Jaegeuk and Chao,
> 
> On 2018/11/15 15:50, Jaegeuk Kim wrote:
>> If namelen is corrupted to have very long value, fill_dentries can copy
>> wrong memory area.
>>
> Is there any scenario that could hit this corruption? Or this is triggered

I didn't see such issue in my test, I guess it may be caused by fuzzing test.

Thanks,

> by fuzzing injection?
> 
> thanks,
> Sheng Yong
> 
>> Signed-off-by: Jaegeuk Kim 
>> ---
>>   fs/f2fs/dir.c | 12 +++-
>>   1 file changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
>> index bacc667950b6..c0c845da12fa 100644
>> --- a/fs/f2fs/dir.c
>> +++ b/fs/f2fs/dir.c
>> @@ -808,6 +808,17 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct 
>> f2fs_dentry_ptr *d,
>>  de_name.name = d->filename[bit_pos];
>>  de_name.len = le16_to_cpu(de->name_len);
>>   
>> +/* check memory boundary before moving forward */
>> +bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
>> +if (unlikely(bit_pos > d->max)) {
>> +f2fs_msg(sbi->sb, KERN_WARNING,
>> +"%s: corrupted namelen=%d, run fsck to fix.",
>> +__func__, le16_to_cpu(de->name_len));
>> +set_sbi_flag(sbi, SBI_NEED_FSCK);
>> +err = -EINVAL;
>> +goto out;
>> +}
>> +
>>  if (f2fs_encrypted_inode(d->inode)) {
>>  int save_len = fstr->len;
>>   
>> @@ -830,7 +841,6 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct 
>> f2fs_dentry_ptr *d,
>>  if (readdir_ra)
>>  f2fs_ra_node_page(sbi, le32_to_cpu(de->ino));
>>   
>> -bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
>>  ctx->pos = start_pos + bit_pos;
>>  }
>>   out:
>>
> 
> 
> 
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> 
> 



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Re: [f2fs-dev] [PATCH] f2fs: check memory boundary by insane namelen

2018-11-23 Thread Sheng Yong 

Hi, Jaegeuk and Chao,

On 2018/11/15 15:50, Jaegeuk Kim wrote:

If namelen is corrupted to have very long value, fill_dentries can copy
wrong memory area.


Is there any scenario that could hit this corruption? Or this is triggered
by fuzzing injection?

thanks,
Sheng Yong


Signed-off-by: Jaegeuk Kim 
---
  fs/f2fs/dir.c | 12 +++-
  1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index bacc667950b6..c0c845da12fa 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -808,6 +808,17 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct 
f2fs_dentry_ptr *d,
de_name.name = d->filename[bit_pos];
de_name.len = le16_to_cpu(de->name_len);
  
+		/* check memory boundary before moving forward */

+   bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
+   if (unlikely(bit_pos > d->max)) {
+   f2fs_msg(sbi->sb, KERN_WARNING,
+   "%s: corrupted namelen=%d, run fsck to fix.",
+   __func__, le16_to_cpu(de->name_len));
+   set_sbi_flag(sbi, SBI_NEED_FSCK);
+   err = -EINVAL;
+   goto out;
+   }
+
if (f2fs_encrypted_inode(d->inode)) {
int save_len = fstr->len;
  
@@ -830,7 +841,6 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,

if (readdir_ra)
f2fs_ra_node_page(sbi, le32_to_cpu(de->ino));
  
-		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));

ctx->pos = start_pos + bit_pos;
}
  out:





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Re: [f2fs-dev] [PATCH] f2fs: check memory boundary by insane namelen

2018-11-16 Thread Chao Yu 
On 2018-11-15 15:50, Jaegeuk Kim wrote:
> If namelen is corrupted to have very long value, fill_dentries can copy
> wrong memory area.
> 
> Signed-off-by: Jaegeuk Kim 

Reviewed-by: Chao Yu 

Thanks,


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